Critique of ‘A path to sustainable energy by 2030’

The November 2009 issue of Scientific American has a cover story by Mark Z. Jacobson (Professor, Stanford) and Mark A. Delucchi (researcher, UC Davis). It’s entitled “A path to sustainable energy by 2030” (p 58 – 65; they call it WWS: wind, water or sunlight). This popular article is supported by a technical analysis, which the authors will apparently submit to the peer-reviewed journal Energy Policy at some point (or may have already done so). Anyway, they have made both papers available for free public download here.

So what do they say? In a nutshell, their argument is that, by the year 2030:

Wind, water and solar technologies can provide 100 percent of the world’s energy, eliminating all fossil fuels.

Big claim. Does it stack up? Short answer, no. Here I critique the 100% WWS plan (both articles).

The articles are structured around 7 parts: (1) A discussion of ‘clean energy’ technologies and some description of different plans for large-scale carbon mitigation. (2)  The amount and geographic distribution of available resources [wind, solar, wave, geothermal, hydro etc.] are evaluated, globally. (3) The number of power plants or capture devices required to harness this energy is calculated. (4) A limit analysis is undertaken, to determine whether any technologies are likely to face material resource bottlenecks that risk stymieing their large-scale deployment. (5) The question of ‘reliability’ of energy generation is discussed. (6) The projected economics of this vision are forecast. (7) The policy approaches required to turn vision into reality are reviewed.

In this post I want to concentrate on (5) and (6) — what I consider to be “The Bad”. But first, let’s look quickly at “The Good” (actually, more like the “Okay”) and then the really “Ugly” parts.

The majority content of the twin papers is focused on making the banal point that there is a huge amount of energy embodied in ‘wind, water and sunlight’ (“Plenty of Supply”), and that a wide diversity of technologies have been developed to try and harness this into useable electrical power.  No critic of large-scale renewable energy would argue any differently, and the size of these resources has been covered in detail by David Mackay. In that context, I wonder what they hope to add to the literature? There’s nothing wrong in this section, and well explained, but it’s just standard, rehashed fare.

Next comes a simple extrapolation of the total number of wind turbines, solar thermal facilities, etc. required to deliver 11.5 TWe of average power (close to my figure of 10 TWe in TCASE 3). This part is similar to that which I provided in TCASE 4 except they use a mix of contributing technologies rather than considering a hypothetical limit analysis for each technology individually. Curiously though, they never really explain (in either paper) how they came up with their scenario’s relative mix of hydro capacity, millions of wind turbines, billions of solar PV units, and thousands of large CSP plants, wave converters, and so on — except in pointing out that some resources are more abundant in deployable locations than others (see Table 2 of the tech paper). They do provide a useful discussion of possible material component bottlenecks for different techs (e.g. Nd for permanent magnets in wind turbines, Pt for hydrogen fuel cells, In/Ga etc. for solar PV), and argue how they can be plausibly overcome via recycling and substitution with cheaper/more abundant alternatives. This bit is quite good.

So what’s “The Ugly”? Well, it’s something utterly egregious and deceptive. In the Sci Amer article, the following objection is raised in order to dismiss the fission of uranium or thorium as clean energy:

Nuclear power results in up to 25 times more carbon emissions than wind energy, when reactor construction and uranium refining and transport are considered.

Hold on. How could this be? I’ve shown here that the “reactor construction” argument is utterly fallacious – wind has a building material footprint over 10 times larger than that of nuclear, on energy parity basis. Further, Peter Lang has shown that wind, once operating, offsets 20 times LESS carbon per unit energy than nuclear power, when a standard natural gas backup for wind is properly considered. I’ve also explained in this post that the emissions stemming from mining, milling, transport and refining of nuclear fuel is vastly overblown, and is of course irrelevant for fast spectrum and molten salt thorium reactors. So…?

Well, you have to look to the technical version of the paper to trace the source of the claim. It comes from Jacobson 2009, where he posited that  nuclear power means nuclear proliferation, nuclear proliferation leads to nuclear weapons, and this chain of events lead to nuclear war, so they calculate (?!) the carbon footprint of a nuclear war! (integrating a probability of 0 — 1 over a 30 year period). I quote:

4d. Effects of nuclear energy on nuclear war and terrorism damage

Because the production of nuclear weapons material is occurring only in countries that have developed civilian nuclear energy programs, the risk of a limited nuclear exchange between countries or the detonation of a nuclear device by terrorists has increased due to the dissemination of nuclear energy facilities worldwide. As such, it is a valid exercise to estimate the potential number of immediate deaths and carbon emissions due to the burning of buildings and infrastructure associated with the proliferation of nuclear energy facilities and the resulting proliferation of nuclear weapons. The number of deaths and carbon emissions, though, must be multiplied by a probability range of an exchange or explosion occurring to estimate the overall risk of nuclear energy proliferation. Although concern at the time of an explosion will be the deaths and not carbon emissions, policy makers today must weigh all the potential future risks of mortality and carbon emissions when comparing energy sources.

Really, need I say more? Can it really be that such wildly conjectural nonsense is acceptable as a valid scientific argument in the sustainable energy peer-reviewed literature? It seems so, which suggests to me that this academic discipline needs a swift logical kick up its intellectual rear end.

So, on to the grand renewables plan. The fulcrum upon which the whole WWS analysis pivots is the section entitled “Reliability”.  Here’s where the steam and mirrors of their WWS dream (sorry, solar thermal pun) really starts to blow off into the atmosphere and shatter on the ground.

First, the authors cite ‘downtime’ figures for each technology (i.e., the period of unscheduled maintenance, as opposed to scheduled outages). From this, they leave the uninitiated reader with the distinct impression (especially in the Sci Amer pap piece) that wind and solar PV is actually more ‘reliable’ than coal! (Who knew? We’d better tell the utilities). They also say that unscheduled downtimes for distributed WWS technologies will have less impact on grid stability than when a large centralised power plant suddenly drops out. Sorry, but I just don’t get this. If the downtime of solar PV is 2%, for instance, and you have 1.7 billion 3 kW units installed worldwide (their calculated figure), then 340,000 of them are out at any one time. That seems rather significant to me…

Next, to overcome intermittency, they claim that for an array of 13-19 wind farms, spread out over an 850 x 850 km region and hypothetically interconnected:

… about 33% of yearly-averaged wind power was calculated to be useable at the same reliability as a coal-fired power plant.

Let’s parse this. By reliability of the coal plant, I assume in this context that they mean its capacity factor (rather than unscheduled outages), which would be around 85% of peak output. Now, wind in excellent sites has a capacity factor of ~35%, so the yearly-averaged power of a hypothetical 10 GW peak wind array of 13-19 farms would be 3.5 GW. Now, following their statement, 33% of 3.5 GW — that is, 1.15 GW or ~12% of peak capacity — would be available 85% of the time. Or, to put it another way, we’d need to install 10 GW of peak wind to replace the output of 1.4 GW of coal? Is that what they are saying? Did they cost this? (hint: no, see below). Perhaps someone else can confirm or reject my interpretation of the statements on p19 of the tech paper.

Also, consider this. Say we instead installed 20 GW peak over this 850 x 850 km area. We’d still only be able to deliver 20 x 0.35 x 0.33 = 2.3 GW of baseload-equivalent power. That is, adding more and more wind doesn’t help with system reliability, as it would for coal.  I suppose the overall system reliability might get a little better as you spread your wind farm array over increasingly large geographical areas, but I suspect that this would be a case of rapidly diminishing returns. How can such a scheme be considered economic?

(Note: I’m not arguing for coal here, just using the power technologies given in their example. For me, insert nuclear instead).

wwwsfigpg63Then they introduce ‘load-matching’ renewables. For instance, they present a “Clean Electricity 24/7” figure for California (see above), in which geothermal, wind, solar and hydro together provide a perfect match to an average power demand curve for CA for a given month (July in this figure). Strangely though, they neglect to mention what happens during the many imperfect, less-than-average days, when it’s cloudy and/or calm for some or most of the day and night (or strings of days/nights), or how much extra capacity is needed in winter months. How is the gap filled if either or both of wind/solar is mostly unavailable? Do the residents of CA go without electricity on those days? Err, no. Apparently, in these instances, grid operators must ‘plan ahead for a backup energy supply’. Riiiight. Where does this come from again, and how will this be costed into the WWS economic equation?

I could go on here, but won’t. This post is already getting way too long, and besides, many of these points will be topics, in and of themselves, in future TCASE posts.

As you’d have already gathered from the above, the economics of WWS is pretty strange. Here’s another example:

Power from wind turbines, for example, already costs about the same or less than it does from a new coal or natural gas plant, and in the future is expected to be the least costly of all options.

How can they justifiably say this, and yet neglect to mention that the power these these technologies produce is variable in quanity, low quality (in terms of frequency control), not dispatchable, diffuse (thereby requiring substantial interconnection), and that their projected energy prices don’t include costs of backup? In other words, in the real world, what exactly does the above quoted statement mean? Nothing meaningful that I can see.

They make a token attempt to price in storage (e.g., compressed air for solar PV, hot salts for CSP). But tellingly, they never say HOW MUCH storage they are costing in this analysis (see table 6 of tech paper), nor how much extra peak generating capacity these energy stores will require in order to be recharged, especially on low yield days (cloudy, calm, etc). Yet, this is an absolutely critical consideration for large-scale intermittent technologies, as Peter Lang has clearly demonstrated here. Without factoring in these sort of fundamental ‘details’ — and in the absence of crunching any actual numbers in regards to the total amount of storage/backup/overbuild  required to make WWS 24/365 — the whole economic and logistical foundation of the grand WWS scheme crumbles to dust. It sum, the WWS 100% renewables by 2030 vision is nothing more than an illusory fantasy. It is not a feasible, real-world energy plan.

I also see that they are happy to speculate about dramatic future price drops for solar PV and concentrating solar thermal with up to 24 hours future storage (Although even they admit it would not provide sufficient power in winter – what do we do then, I wonder? – have huge capacities of coal and gas on idle and as spinning reserve?). Well, I guess that if analysts like Jacobson and Delucchi are willing to forecast such optimistically low costs for future solar, then we can be quite comfortable doing the same for IFR and LFTR, the Gen IV nuclear. What’s good for the goose…

Finally, a quick note on the section “Policy Approaches”. I found one thing particularly amusing. They start by emphasising the critical need for feed-in tariffs (FITs), to subsidise the initial deployment of WWS technologies, because these deliver a necessary kick start towards lower future costs. It’s ironic then, that they end with a quote from Benjamin Sovacool (2009) which says:

Consumers practically ignore renewable power systems because they are not given accurate price signals about electricity consumption. Intentional market distortions (such as subsidies), and unintentional mark distortions (such as split incentives) prevent consumers from becoming fully invested in their electricity choices.

Well, excuse me, but if FITs, and WWS technologies that are priced without adequate storage/backup, are not market distortions and subsidies, then what the hell is?


Charles Barton at Nuclear Green has two further useful critiques of the WWS papers here and here; these follow on from his earlier dissections of Jacobson, Archer’s and Sovacool’s work.


Appendix: Further comments on WWS from Dr. Gene Preston of SCGI:

By profession I do transmission studies for wind and solar clients. My company name is TAC meaning Transmission Adequacy Consulting. I currently am doing studies all across the US.  “A path to sustainable energy by 2030” omits the transmission system needed by 2030.  Because the wind and solar and water and geothermal projects are not in the locations of the existing power plants, new lines will be needed.

Looking at the graph on page 63, and carefully measuring scales on the graph, I estimate that there is 40,000 MW of wind and 40,000 MW of centralized solar on that graph. The reason I omitted rooftop solar is because Jacobson has its contribution to be rather small.  For example, multiplying out the numbers on page 61 you will get 5.1 TW of rooftop solar and 26.7 TW of large scale solar of 300 MW size in farms, much like wind farms.  This seems reasonable since centralized solar is twice as cost effective as rooftop solar.  Since the rooftop solar is small I will omit it from these comments.

That leaves us needing 80,000 MW of new wind solar and geothermal generation just to serve California. I think an estimate of 500 miles from wind and solar resources to major load centers is reasonable.  A 500 kV transmission line is rated at about 2000 MW max power. But you don’t want to operate it at that power level because the losses are too high and there is no reserve capacity in the line to handle the first contingency problem. Therefore I will estimate we will load the new 500 kV lines to about 1500 MW on average.

So we have 80,000 MW of renewable sources widely scattered around the Western System (WECC) with each carrying 1500 MW so that we need roughly 50 new 500 kV lines of 500 miles each, for a total length of 25,000 miles.

The article assumes there is little solar power energy storage and it also assumes the wind be blowing at night.  We know for sure that the solar power is not available at night so we are nearly totally dependent on wind for night time energy.  You are going to ask about the geothermal energy.  One geothermal project I recently worked on for determining the transmission access for looked like a good project until the geothermal energy extraction failed to work.  Recently other geothermal projects have created human induced earthquakes.  Geothermal energy seem less likely today than just a few years ago.

So we are nearly totally dependent on wind energy for the night-time CA energy as envisioned in the 100% renewables by 2030.  If we plan for those few occurrences when there is no wind in the WECC system, we must interconnect WECC with the rest of the US so CA can draw power from other wind generators that do have wind (hopefully) outside the WECC area, such as the Texas coast and east of the rocky mountains where massive wind farms can be constructed. However we will need at least 40,000 MW of lines that I estimate will average 2000 miles in length. If we used 500 kV lines, we would need about 25 of these lines bridging from WECC to the US eastern grid and ERCOT and the total length would be about 50,000 miles. By 2030 we would need 75,000 miles of new 500 kV lines just to serve California with 100% renewables. Considering that we have the period from 2010 to 2030, that means we would have to construct about 4000 miles of new 500 kV lines every year from now until 2030 for the renewables plan as outlined in this article to work.

How much do these lines cost? Probably about 2 million dollars per mile.  Also, the 500 miles is just an estimate.  If you have specific projects in mind that eliminates some of the uncertainty in estimating costs.  For example the distances might be less to wind generators.  However I suspect that opposition to the wind generators unsightliness and opposition to power lines will result in longer pats for lines zig zagging around the countryside and the wind generators being not allowed anywhere on the coast, so I understand that Mexico is the desirable place for wind.  But if you were to string out 40,000 MW of wind, I bet you would find the 500 miles was not that bad a guesstimate after all.  The first few sites might be closer to load centers, but opposition is likely to drive them farther away.  The construction time for lines is mostly how long it takes to get all the ROW and get approval to build the lines.  How many years will a line be held up in hearings?  Add one year to that number of years and you have roughly the time it takes to build a new line.  Now try to build new lines across the Rockies and see how long that will take – decades I predict, if ever.

In sum, I do not believe this is achievable at all.  Therefore the concept envisioned in the SA article is not a workable plan because the transmission problems have not been addressed.  The lines aren’t going to get built.  The wind is not going to interconnect.  The SA article plan is not even a desirable plan. The environmental impact and cost would be horrendous.  Lets get realistic.

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By Barry Brook

Barry Brook is an ARC Laureate Fellow and Chair of Environmental Sustainability at the University of Tasmania. He researches global change, ecology and energy.

203 replies on “Critique of ‘A path to sustainable energy by 2030’”

Oh, and in terms of these lifecycle carbon emissions, the vast majority come from the worst-case mining and enrichment scenarios, but of course with IFRs we would have NO mining and NO enrichment for hundreds of years. So the 9-10 grams reported by the IAEA, IPCC and others that correspond to lifecycle carbon costs of Gen II reactors would nearly disappear, especially if you built the power plants using low-CO2 concrete and steel smelted at an electric smelter, which is entirely feasible. Jacobson’s numbers, when considering those very reasonable scenarios, transform themselves from merely outrageous to absolutely ludicrous. IFRs produced in this manner would have as close to zero for a carbon lifecycle cost as one could possibly achieve from any type of electrical generation, and certainly would be far lower than wind or solar.


Gene Preston,

Returning to your Appendix in the header article for this thread, and also my question (#33470) and your reply (#33622), I would like to check these figures again before I use them.

Based on your figures I calculate the cost of transmission for solar as $625/kW (no interstate interconnections) and for wind is $3125/kW ( including interstate intgerconnections).

The transmission cost for wind is about 50% higher than the cost of the wind farm. These figures seem too high to me. Can you please point out if I have understood this correctly, and if not where I have gone wrong?

My calculations are as follows:

solar capacity = 40,000 MW
Av line length = 500 miles
Av power = 1500 MW
No. of lines = 25
Total length = 12,500 miles
Cost per mile = $2 million
Total cost = $25 billion
Cost per kW = $625

Wind capacity and cost is the same as for solar, PLUS the cost of interstate interconnections:

Interconnection capacity = 40,000 MW
Av line length = 2000 miles
Av power = 1500 MW
No. of lines = 25
Total length = 50,000 miles
Cost per mile = $2 million
Total cost = $100 billion
Cost per kW = $2500

Total for wind = $625 + $2500 = $3125

Gene, Do I have a mistake or do you think these figures are roughly correct?


Barry #34182, nice find with the TBAS article on pyroprocessing in South Korea.

This article indicates the Koreans are currently operating lab scale pyroprocessing, and intend to build an engineering scale mockup by 2011 (which I take to facilities, hot cells, control systems, transport systems, services etc. but not actually separating transuranics). I assume from there it might take ~1-2 years to scale up the lab process, meaning process development on the separation step itself, development of lots of process monitors, and a metric assload of documentation.

Nuclear and IFR skeptics seize on the fact that there is no operational pyroprocessing facility, as if no-one ever scaled up a process before. This is very conventional process engineering, and a quick look at the Korea Atomic Energy Research Institute shows obvious capability to carry this through.


Peter, I normally say that wind is $2/w and estimate a 500 mile 345 kV line good for 1000 MW costing $2 million per mile. That equates to $1/w for transmission. That is a good estimate for the $5 billion dollar CREZ lines in west Texas which I estimate will allow about another 5000 MW of new wind, and that is from my own load flow transmission analysis. So that also equates to $1/w transmisson. However that transmission is just to bring power from the wind generators to the load centers in Texas. The reason my wind cost was so high is that I was adding in massive amounts of new transmission lines so that the entire Texas region could interconnect to other regions like WECC and the eastern grid. If Texas wanted to make renewables more reliable and retire base load coal and nuclear plants, it would have to rely on imported power from other areas. Now the transmission costs skyrocket because of the length of these lines connecting between large regions within the US. You could leave out these interconnecting lines and the cost of transmission would probably be about $1/w, but it would not be as reliable as interconnecting. You probably should show separate transmission costs for just connecting up wind and solar and that might be the $1/w and then how much you want to spend on interconnecting and gridding up the US is up for grabs and depends on how much power you want or need to move around in large blocks from one geographic region to another. Hourly simulations are needed to study this in detail. I think that after careful study you will find that renewables are never reliable enough regardless of how much transmission you add connecting the regions together.


With regard to the wind capacity factors, CF, in west Texas the wind CF was 33% in 2006 and dropped to 25% in 2007. I asked one of my wind clients why the CF was so much lower in 2007 and he said the wind just didn’t blow as much in 2007. So there you have it. Wind is rather fickle.


So the 9-10 grams reported by the IAEA, IPCC and others

Minor correction – IPCC does not give any CO2 figures, rather it simply defers to WEC 2004. This is in the WG3 report (IIRC they reprint the entire summary chart.)

Oh and no, they are not to be trusted. Sovacool throws out both IAEA and WEC. Jacobson’s figures are Sovacool’s.


Udiv, it is true that the Wikipedia Capacity Factors, calculated from Net Summer Capacity (which should be approx. avg over the year), will be slightly out – maybe 10%. But the results are all calculated similarly and do not show any evidence of Jacobson’s greatly increased Capacity Factors. Also the CF of new Wind Turbines does not tell the CF of Wind Turbines over their entire life. As they age maintenance breakdowns become more common. Debris & Ice collecting on the blades reduces efficiency, as well as cracks and distortion that may develop in the blades. Because of the difficulty & cost of Wind Turbine maintenance, and the low value of their power, they will likely be at the bottom of the list for maintenance priority.

The following document shows European avg Capacity Factors over 2003-07 were less than 21%.

Capacity factor of wind power realized values vs. estimates:

Tom Adams – Review of Wind Power Results in Ontario shows 22.3% CF:

As for the EERE/NREL chart, their data is highly suspect, and does not necessarily imply much higher avg CF’s for newer Wind Turbines, on average.

The following critiques of NREL documents show good examples of the extreme bias and shoddy analysis of the NREL:

U.S. DOE Report “20% Wind Energy by 2030” Presents Implausible Scenario:

Errors and Excesses in the NREL’s JEDI-WIM Model that Provides Estimates of the State or Local Economic Impact of “Wind Farms”:

Click to access errors-in-nrel-model.pdf


Yeah, so the number used for capacity is summer which is halfway through the year so therefore that is approx average capacity of the year.

And the same criteria is used for each year, so once again no sign of the major increase in CF for new wind turbines.


Also note that the CFs in the Boccard analysis, which use more accurate methods, match well with the Wikipedia numbers, averaged over the 2003-07 period.


Yeah, so the number used for capacity is summer which is halfway through the year

No, the figures are at the end of the year. This is very clear if you go back to the primary source:

Capacities are reporter in quarter-years; the annual figures are what exists at the end of the year. The 2008 figure is 25,369 MWe cumulative; as of July 2008 (2Q) it is only 19,549 MWe.

Also note that the CFs in the Boccard analysis, which use more accurate methods, match well with the Wikipedia numbers, averaged over the 2003-07 period.

This is pointless – they all share the same systemic error. Their average has the same error.

Here’s my rough attempt to fix the calculation. From the AWEA’s 2008 1Q-3Q and annual reports, here are the wind capacities:

end of 2007 – 16,823 MWe
1Q 2008 – 18,303 MWe
2Q 2008 – 19,549
3Q 2008 – 21,017
4Q 2008 – 25,369

With simple linear interpolation, I get an average capacity of 19,990 MWe over the year 2008. Note how huge the error is! It’s even further exacerbated that 2008 growth was nonlinear – much higher in the second half of the year than the first.

Combining this with the generation statistics from the EIA, and taking note that 2008 is a leap year, I estimate a capacity factor of 52,026 GWh / 366 days / 19,990 MW = 29.6%, with a range of 28.1%-31.3% (the error introduced by the linear interpolation).


Hi Gene Preston,

Thank you for the clarification for the $/W figure for transmission for wind power. It confirms (slightly increases) the $/W figure I calculated for the ‘without interstate interconnection’ case, which I calculated from your figures to be $625/kW (or $0.625/W).

I now have a better understanding of the ‘ball park’ figure for the cost of transmission for wind power.

By the way, just for interest, the wind farms built recently in Australia are running at about A$2.4/W, so about US$2.2/W. Here is a list from ABARE:

Not on this list is the Waubra wind farm, commissioned in September 2009. $2.344/W.

So far the transmission costs are not showing up anywhere that I have seen. They are being abosrbed (ie carried by other generators and the public) because as yet, wind is only about 1% of generating capacity.


Douglas Wise,

I have to apologise: I have not done any more on your question about tidal power. My focus is on another paper at the moment. I am not sure when I will get to look at your question.


Peter, thanks for the wind information. Since these cost numbers keep fluctuating, we won’t be able to nail down the costs precisely.

Warren, the time of the peak has nothing to do with the capacity factor. You can define the capacity factor as an average MW divided by the peak MW over a time period. Or you could define CF as the actual energy delivered divided by the maximum energy that could have been delivered if the generator had run at 100% of its capacity for the same period of time. In either case wind is about 30% capacity factor. Unfortunately west Texas wind has its highest powers when the Texas load is at minimum levels and then during the summer peak load period the wind is at low output. However wind along the Gulf coast of Texas tracks the daily peak load better because there is a daily afternoon breeze that blows inland that coincides with the daily electrical peak so the economics for those wind generators may be better than the ones in west Texas. However there is much more opposition to the coastal wind than there is in west Texas, where the farmers have open arms for wind in those regions and the populations are sparse.


Peter Lang # 34807

I appreciate that tidal power is always going to be a bit part player and that you are currently concerning yourself with the pros and cons of the more “popular” renewable technologies.

I raised the subject of tidal lagoon power because it seemed, from what I read in MacKay (and later in, to offer potential advantages over other renewables in its ability to provide peaking power on demand which could fit in well with nuclear baseload, an attribute that additional pumping from wind might enhance. As a layman, I might be being naive and therefore wondered whether you could venture a quick but more informed judgement on the matter. I am much less persuaded of the virtues of tidal stream and barrage approaches.

I appreciate that you are primarily concerned with Australia and I know little of your tidal ranges. As an inhabitant of a small island nation (UK) with good tidal ranges, perhaps I should seek my answers nearer home.


…No, the figures are at the end of the year. This is very clear if you go back to the primary source…

That explains the discrepancy. I assumed Net Summer Capacity actually meant Summer Peak Capacity, whereas it seems that it doesn’t. Although looking at the StatCan Canadian Data for Wind Capacity & Energy Output, it does look like an average of the two end of year nameplate capacity or the actual capacity installed in summertime. So recalculating, using the average of the two end of year capacity numbers, I get USA 2007: 27.6% CF, 2006: 29.1%, 2005: 25.5%, 2004: 24.5%, 2003: 23.0% – which averages out to 25.9% 2003 to 2007 – which is very close to Boccard’s number of 25.7%, using more accurate methods. The USA numbers are very good compared to most European countries. Note the drop of CF to 27.6% from 29.1% 2007 to 2006, in spite of a ~37% increase in Wind Capacity. That does not show any indication of the large rise in CF for new Wind Turbines, that Jacobson claims. I suspect USA CF’s, averaged over several years, will decrease over the next 20 yrs

…This is pointless – they all share the same systemic error. Their average has the same error…

Not True. Boccard does not use that type of analysis, but uses actual Wind Farm output data. His data for Europe should be as accurate as you will get anywhere, and does indeed indicate an actual CF for Europe of 21%, 2003 to 2007.

What would be really informative, would be if Gene Preston, would give us some information on line loss on long distance Wind Power Transmission lines. My understanding is that transmission line conductor sizes are determined (besides being able to carry peak load) by the marginal cost of increasing conductor size equals the marginal value of the line loss power saved. Since Wind Farms average about 30-40% of peak output, larger line loss would be expected, than for a baseload supply. It is proper to reduce actual Wind Farm energy production by the amount of that line loss, in calculating Capacity Factor.

Also regarding Capacity Factor calculation. Most new Wind Turbines come with only a 2 year warranty. And I believe blade changes are expected before end of the 20 yr projected lifespan. Any major repair on a Wind Turbine, such as a blade change, gearbox or generator replacement, requires a giant Crane to be brought to site. I’ve been told that you have a minimum $100k charge on that. And a serious logistical challenge. I suspect that when serious maintenance, such as that occurs, the Turbines will be left shutdown for long stretches of time, possibly waiting to bring a crane in for multiple turbine repairs, rather than just one. These factors will not become apparent until a large portion of the fleet of Wind Turbines reaches mid-life.


Note the drop of CF to 27.6% from 29.1% 2007 to 2006

This is a statistical artifact: your uncertainty is much larger than the difference between your two numbers (try calculating it). And your approximation doesn’t hold: the rate of growth over 2008 is not constant, but was much faster in the second half of the year (see earlier comment). I calculated 29.6% for 2008.

Not True. Boccard does not use that type of analysis, but uses actual Wind Farm output data.

A quick glance shows Boccard’s method is the same as ours, and uses national generation statistics (not individual wind farms) for his 2003-2007 figure.

And if you want statistics of individual wind farm generation statistics, I already linked to the EERE numbers of exactly that, which support the 33-35% figure:

His data for Europe should be as accurate as you will get anywhere, and does indeed indicate an actual CF for Europe of 21%, 2003 to 2007.

I too have calculated capacity factors in the low 20’s for Europe (see my blog). But here we are talking about the US, not Europe. They have different numbers.


Hi Warren, rather than giving you just one line’s losses, I ran some load flow simulations for ERCOT on the planned 10,000 MW of wind in west Texas for 2013. First, ERCOT has a rather strong transmission system, and the 80,000 MW of generation for the summer peak of 2013 has only a 2.2% transmission system loss for the whole system at peak load. The light load case for the spring of 2013 has 31656 MW of generation and the total system transmission loss is 1.9% of that generation. In the summer peak case the wind is very light around 10% which is based on experience, so incremental losses from wind at summer peak are not important because the wind will never run a high output during the summer peak. However the light load case is the one most likely to have high wind output. ERCOT has set the west Texas wind at 4120 MW for the light load spring case, which is the expected value of wind, which is highly variable of course, but 4120 MW is typical out of 10,000 MW and the light load level is very frequent. I get e-mails every day on the load for ERCOT and I can say that we spend many many hours in a rather light load condition. So the question is, what is the incremental loss from wind in the light load case when wind is varied in output? We can look at the losses in two ways and we get two different answers. If we simply vary the west Texas wind and vary the total system load, we find that dropping off the 4120 MW of wind and adjusting the load downward shows that there was an incremental transmission loss of 144.4 MW or an incremental loss of 3.5%. If we however decrease the wind to 0 MW and increase other genreators in ERCOT to hold the load constant, then the incremental loss due to wind is only 27 MW or 0.7%. If I had run a case with west Texas wind at 10,000 MW I’m sure the incremental loss would have been a higher percentage. But that condition has such a short period, its calculation really has no meaning. Also, we would have to decide how to do the dispatch, against load or against other generators and the results would be dramatically different. I must also say that these losses are quite low because this load flow case has the new CREZ lines in the case, i.e. the $5 billion investment in new 345 kV lines, which have substatially reduced losses. So, the losses are likely to be high only in systems that try to use too low voltages, such as 69 kV lines, and for systems that are loading lines too high, i.e. at thermal limits for extended periods. If the system is made reliable from an N-1 outage standpoint, the transmission losses are likely to be low, as stated above.


Douglas Wise,

I happenned to come across a paper by Martin Thomas (AM, FTSE, HonFIEAust) “Energy Security – The Options for Australia”. I thought you might be interested in what he has to say about tidal power:

Tidal technologies convert tidal flow energy into electricity using large scale water turbines. Tidal barrages with differing water heads (high tide to low tide) generate from the head difference, large in temperate climes but negligible in the equatorial oceans. Tidal power sites are often remote from load centres, for example the Secure Bay – Walcott Inlet site in Western Australia which, although a site of very high potential, cannot find local economic application.

In Australia Tidal Energy Pty Ltd has successfully trialled a high efficiency shrouded turbine (efficiency > 60%) and plan a 3.5MW facility in north west Australia. Small (<1MW) propeller turbines are being demonstrated in the UK and Norway. A 1.2MW unit has been connected to the Northern Ireland grid since 2008. Other MW scale farms are foreshadowed internationally.

A 240MW barrage tidal power plant has been in operation in France since 2006, producing 600GWh at 28% capacity factor. Other such facilities operate at Canada’s Bay of Fundy (18MW) and Kislaya Guba in Russia (0.5MW). Tidal power scheme costs are site specific but are believed to range from $1,500-2,000/kWp.

Like wind power, wave and tidal power schemes raise environmental concerns including visual pollution of coastal seascapes and possible harm to marine creatures. Tidal power changes to estuarine ecosystems, turbidity, salinity and sediment movement may also limit their applicability.


In response to transmission costs, the Australian Energy Market Operator (AEMO) gave a presentation to a conference in Brisbane this week. Among other things they have costed a 5000 MW transmission system from the Cooper Basin to carry power from the potential geothermal hot rock plants (that may get built there one day) to three cities Sydney (4000MW), Melbourne (500 MW) and Adelaide (500 MW). The cost for DC ranged from $0.5 – $0.74/W and for AC $0.78-$1.2/W.

Of course we have no real idea what the cost per W will be for the power plant as one is yet to be built at commercial scale. But the transmission cost will be significant proportion of the whole deal.

This is a significant “hidden” cost for renewable energy sources that needs to be build a long way from the load.


… This is a statistical artifact And your approximation doesn’t hold: the rate of growth over 2008 is not constant, but was much faster in the second half of the year …

I checked that out against AWEA quarterly data, and you are correct, the Wind Capacity growth is concentrated at the end of year for 2007 & 2008. Recalculating using Quarterly data I get:

Q1: 2007/8/9 = 31.9% / 33.1% / 29.3%.
Q2: 2007/8/9 = 33.1% / 36.8% / 28.1%.
Q3: 2007/8/9 = 26.8% / 22.1% / 22.2%
Q4: 2007/8/9 = 30.0% / 29.3%

I don’t see any indication of Jacobson’s big improvement in Wind Capacity Factors, in the USA. 2009 has dropped considerably from 2008 & 2007 in spite of 77% of Q1 capacity being after 2003.

… A quick glance shows Boccard’s method is the same as ours, and uses national generation statistics (not individual wind farms) for his 2003-2007 figure.…

That is only for USA data, using averages of end-of-years (not Wikipedia’s method). The European data, which is what the study is about, does use Wind Farm & Utility data if you read the report:

“…Our main reference is the wind energy barometer of think-tank EurObserv’ER with corrections from more reliable sources, whenever available. While there are only minor revisions regarding installed capacity from year to year in all sources, generation data show important discrepancies, both between yearly report so if the same source and between different sources. We have favored the most recent reports and those of TSOs over research institutes….”

The conclusion that European Wind Output averages 20.8% CF over 2003 to 2007 is valid.

… I already linked to the EERE numbers of exactly that, which support the 33-35% figure:…

Those numbers are clearly high, they do not match actual EIA data for those years. And you can select high output Wind Farms, which are the Offshore & Coastal areas, which are very expensive or very limited. And even their study shows no improvement in those numbers after 2004. You can always increase CF by going offshore, but the cost per avg kw is much higher than onshore, which makes Jacobson’s overpriced plan all the more infeasible. Coastal regions are where the rich commonly live, and they can & do block Wind Farms – very effectively. The Wind Farms are going in impoverished areas, where landowners can be bought for a meager royalty. No correlation to best Wind Sites. Even Pickens has stated: “…I’m not going to have the windmills on my [68,000 acre] ranch. They’re ugly..”

… But here we are talking about the US, not Europe:…

No, we are talking about Worldwide. Jacobson is trying to justify his 30% Worldwide in his report, using USA data. He disputes Brooks calculation, using 23%. From what I see Brooks 23% for Worldwide Wind, especially for a major build, is a pretty good estimate, if anything it is high. Especially when we begin to see the effects of Wind Turbine Age, Nimbyism, Climate change and Grid Inability to absorb Wind Peaks.


Martin Nicholson,

Thank you for the figures for transmisson costs from the geothermal sites to the capital cities. Tjos figures align well with the figures Gene Preston provided. I suspect the average distance to the best solar sites (Tanami desert) is about double so a bit less than double the cost per watt you mentioned. Perhaps $1.20/W as an average cost for transmission from the optimum solar thermal sites. Any thoughts?


Gene Preston, thanks for the info on the Texas Transmission system & their low line losses. But, what I would be more interested in, and is more relevant to this discussion, is the expected overall line loss on the long distance transmission lines, needed for Jacobson’s plan. For instance the ones you proposed for sending 40 GW of Texas Wind Energy to California. 25 lines, 500 kv, 2000 miles each.



I did some distance estimates for the AEMO lines for Gene and came up with about 1,100 km to the connection point in Sydney, 1,100 km to Melbourne and 800 km to Adelaide all in different directions. The actual cost range for 5000 MW DC was A$2.5 – 3.7 billion. AC was $3.9 – 6.0 billion.

It could be 1.200 km from the Cooper Basin to the Tanami Desert in the opposite direction so your “about double” is about right..


Mark Z. Jacobson says in post #34345, Response No 2:

“With regard to land and materials footprints on his TCASE web site that he refers to, Brooks confuses the definition of footprint with spacing area. He pretends that the space between wind turbines is an apple-to-apple comparison of the actual land taken up on the ground by nuclear power plants, when in fact the real footprint of wind covering the ground to power, for example, the U.S. vehicle fleet, is 770-1100 times less than that of nuclear.”

This calculation appears to be wrong by several orders of magnitude.

As Barry pointed out, the land use due to mining, material handling, manufacturing and transport is much greater for wind than it is for nuclear.

Purely on the basis of the land area used for the actual power station we can compare a single modern wind power station and a 1980’s nuclear power station. The reason I picked these is because the data is readily available. Using an old Gen II power station for the comparison biases the result towards wind because newer power stations require less area.

We can compare on the basis of the total site area or on the area that is excluded from all other uses. The total site area for wind power is the total land area occupied by the wind farm. For the nuclear power plant it is the power station site area. The area excluded from other uses for the wind farm comprises the area of the foundations, site erection areas and the access roads. For the nuclear power station it comprises the buildings, roads and parking areas and set down areas.

Here is a comparison for Torness NPP, UK and Capital Wind Farm, NSW Australia.

Capacity; MW; 1250; 132.3
Economic life; years; 40; 20
Life time energy; TWh; 332; 8.11
Total Site Area; ha; 143.7; 1200
Area excluded from other uses; ha; 30; 22
Total site area per life time energy; m2/GWh; 4.33; 1480
Area excluded from other uses per life time energy; m2/GWh; 0.9; 27.1

Comparing these two power stations, wind requires 340 times the total site area of nuclear and 30 times the area excluded from other uses. If the area required for mining, milling, materials handling, processing, fabricating, manufacturing, and transport was included, the comparison would be even more favourable to nuclear.

Jacobson claims “real footprint of wind covering the ground … is 770-1100 times less than that of nuclear.” Whereas, the comparison of Torness NPP and Capital Wind farm suggests wind requires 30 to 340 times more areas than nuclear. It seems Jacobson has mis-calculated the case for wind power by a substantial amount.


Click to access EPD_Doc_-_Final.pdf

Click to access 05_0179_d-gsassessmentreport_version3.pdf


Warren, I looked inside a WECC case and located the most heavily loaded 500 kV line I could find. It was 52.3 miles long and is rated at 3767 MVA and had 1719.8 MW flowing into one of the line and 1709.1 MW flowing out the other end. The line loss would be 10.7 MW. If it was 523 miles long I would assume the line loss would be about 107 MW for about 1700 MW flowing on the line, or about 6% line loss. Does this help? …Gene


You asked about the loss if it were 2000 miles long. I guess it would be about 24% line loss. Also, if the loading is increased the loss would be a higher percentage due to I2R. Thats a lot of line loss and shows the problem of trying to transmit too much power over too great of distances. I am surprised the loss is that high. Possibly the idea of getting wind to CA from east of the rockies is not such a good idea just based on high losses of the lines.


So you put in 1900 MW of wind that is east of the rockies and transmit it 2000 mi to CA and take out about 1500 MW of power. I haven’t checked the distance. Is it really 2000 miles? Let me check…Following interstates 15 and 70, the distance is more like 1400 miles. So the losses would be less than 24%, only about 17%. Without an actual routing plan or transmission plan, we do not know the lengths of the lines.


Thanks for the information, Gene.

So this is what I estimate as a basic summary of supplying California with 40 GW peak of Wind Energy from Texas:

– 27 of 500 kv AC transmission lines
– 1400 miles long or 38,000 miles total
– @ $2M per mile, that’s $76B total
– each taking 1733 MW peak Texas Wind Energy, total 46.8 GW pk input
– 17% line loss at peak -> 1439 MW peak output each or 40 GW total output

– approx. 80% of Wind Installed Capacity req’d at Peak or 59 GW Texas Wind Installed Capacity
– at 30% CF, that’s 17.6 GW avg total input
– say avg line loss of 13%
– that’s 15.3 GW avg total output
– cost of $76B/15.3GW = $4.9K per avg delivered kw
– 59 GW @ $2.5k/kw = $148B for the Texas Wind Farms
– total cost $14.5k per avg delivered kw

And that is only supplying 38% of the 40 GW needed. And you would have a hard time finding 25 GW’s of complementary load, with Renewables, be it Hydro, Solar or Geothermal, without shedding substantial energy when that wind from Texas is near max.

Mighty expensive way to get unreliable energy. And I would call that a worst case scenario of a HIGHLY CENTRALIZED ENERGY SUPPLY.


I was having a discussion with Dan Coffey on

who is pro wind and not so enthusiastic about nuclear power. I did some new cost estimates and losses for transmission using 765 kV lines and trying to bring in 20000 MW of “base load” wind 1400 miles away from Los Angeles. Here is what was posted:

Let’s suppose California wanted to get 20,000 MW of wind power “base load” from farms east of the Rockies. Using Jacobson’s diversity of wind we could assume that the wind is reliable for 33% of that capacity. That means that we need to install 60,000 MW of wind generators to get 20,000 MW of base load generation out of wind. But let’s suppose that frequently the wind blows at 50% of the total installed 60,000 MW. That means that CA would have to install 30,000 MW of transmission to insure that they get 20,000 MW of base load wind and then didn’t throw away too much energy when wind is more than 50% of the installed capacity. By the way, by using DC connections to the same wind farms east of the Rockies, you could sell the excess wind to loads east of the Rockies when the wind was over 30,000 MW. Even if the lines have a thermal capacity of 30,000 MW, you would not want to normally load them to that level anyway because the losses would be too high. So by expecting them to be loaded to 20,000 MW from wind continuously, the losses would be lower and you would still have some reserve capacity. Let’s assume that the 30,000 MW is going to be on 765 kV AC lines based on the AEP 765 kV concept:

Click to access AEPInterstateProject-Why765kVAC.pdf

Although AEP rates the lines as 2770 MW max, the thermal loading could easily go to 5000 MVA. I think with some voltage support substations intermediately positioned between east of the Rockies and LA, you could count on the 30,000 MW wind to load the 765 kV lines to 5000 MW and then the 20,000 base load wind condition would load each 765 kV line to 3330 MW. Getting all the lines to take 5000 MW at the same time would be an engineering challenge and require SPS or special protection schemes to drop 5000 MW of wind if a 765 kV line tripped out of service.

I looked in the eastern grid data and found a 765 kV line rated a little over 5000 MW. I set up a 700 mile long 765 kV line with 3333 MW on the sending end. The line loss was observed to be 2.83%. The phase angle shift was 38 degrees. If we scaled this up to 1400 mi from Kansas to LA, the loss would be about 5.6% at 3333 MW injected in Kansas and about 3140 MW out in LA. You can estimate the costs of this line from the reference given above. It’s about 5 million dollars per mile or 7 billion dollars for a single 5000 MW line from Kansas to LA. We will need six of them to get up to 30,000 MW line capacity. The lines are 42 billion and adding in substations would probably increase the cost to $50 billion. It could require three substations per 1400 mile line, or a total of 18 substations. Then the amount of wind would be 60,000 MW nameplate and would cost about 120 billion dollars. So, the total cost of that base load wind generation would be about 170 billion dollars. This is $8.5/watt. Nuclear plants would cost in the 5 to 10 $/w range and not need the 1400 mile long transmission lines. I think the time required to build this wind and transmission system is about the same time it takes to build a nuclear plant, or about 10 years. If you are anti transmission you should go for the nuclear plants.


Gene Preston,

Earlier in this thread you gave me a ‘ball park’ figure of $1/W for the capital cost of transmission for wind power.

Could you give me a rough $/MWh figure based on the same assumptions as you used previously. You would have a much better idea than I of any other FOM costs that should be included.


Hello Peter,

EHV transmission lines can serve two purposes: 1) serve as a lightly loaded intertie between two larger systems for the purpose of delivering standby power if one of the areas becomes emergency deficient in its generation, and 2) delivering power from a large generator to a load center. Its not appropriate calculate a kWh energy cost for 1) because little energy is delivered, so I will discuss 2) the delivery of energy from a large power plant or source of power such as hydro or wind or coal or nuclear. The $1/watt number I proposed assumed a 1000 MW line costing $2 million per mile and being a length of 500 miles. I have seen the AEP cost estimate of a 765 kV line being $5 million per mile and thermal rating of 5000 MW, although AEP recommends loading it at a much lower level. The energy cost depends on how the line is loaded, its length, and its voltage. For example, the 1000 MW 345 kV line should be loaded to about 500 MW if connected to a remote nuclear plant. This greatly reduces losses and also is near the surge impedance loading, which is 400 to 500 MW for a 345 kV line. The surge impedance loading insures a flat voltage profile along the line. So lets assume we have the 345 kV line loaded to 500 MW and its 500 miles away and the line costs $2 million per mile. That cost would be $2/watt. Amortize this capital cost over 30 years at 5% APR would be an annual capital cost of (2$/w)(.05)(1.05^30)/(1.05^30-1) = $0.13/w annually. Assume the nuclear plant runs 90% of the year. Then the cents per kWh would be (13000 cents)/(8760*.9) = 1.65 cents per kWh. With this design of loading the line to 500 MW, we still have another 500 MW reserve for emergency loading, such as when other power plants trip off line and/or other large 345 kV lines trip out of service, so that system becomes reliable by having that reserve transmisson capacity. Now let’s consider wind remotely. Because of the variable nature of wind, which has an average 30% capacity factor, meaning if you had a large enough area, you might expect to see less diversity so that the peak wind power is reduced and the minimum wind is increased. For wind I would design the transmission system to fully load the transmission at about 2/3 of wind total capacity which would correspond to our 345 kV transmission line being loaded to 1000 MW and then the 1/3 rd average wind would correspond to 500 MW “base loading” just as for the nuclear plant. The total wind generation installed capacity would be three times the base load MW level. Therefore it would take 1500 MW of wind connected to our 1000 MW transmission line and the energy delivered would roughly be the 500 MW continuously, so the cents per kWh would be 13000/8760 = 1.49 cents per kWh for 500 miles of 345 kV 1000 MW transmission connected to a 1500 MW wind farm. Scale the cost roughly linearly with distance. Does this help?



Thank you for that excellent explanation. I will use $0.015/kWh (or $15/MWh).

I think this would be a conservative figure (ie on the low side) because I expect the lines must be designed to carry the full peak power from each wind power station and each region. Would you agree with that?

I am preparing a paper (very approximate) to compare the CO2 emissions and costs of supplying all Australia’s electricity with one of six options. The six options comprise different technology mixes rerplacing coal fired generation as it is decommissioned at the rate of 1GW/yr for black coal and 0.4 GW/yr for Brown coal. The six option are:

Business as usual
CCGT & nuclear
CCGT & Solar Thermal
Wind, Solar Thermal, CCGT & OCGT

For first three options the transission cost is similar so I have not factored in any extra costs. However, for Wind and Solar thermal transmission is a significant extra cost. So I need to add it in.

My assumptions are that wind greneration is mainly along the southern and sourth-east coastal fringe of Australia. Solar thermal power stations are distributed throughout the insolation regions of Australia – basically the desert areas over an area of 3000 km by 1000 km. Average distance from the main population centres to the centre of this region is 2000 km. Each solar thermal power station will be 250 MW with energy storage sufficient to give 24 h operation and 8000 generating hours per year (as per NEEDS, 2008) (don’t laugh at me :) ).

So I will use $15/MWh for wind. Do you have any comment on a vlaue I should use for my solar thermal ‘baseloadf power stations located in the desert.


Hi Peter, you may want to install enough transmission to fully handle all the wind capacity, however the independent wind developers here in the US will continue building new wind generation past the point where they can operate all the time up to maximum output power. They have to encounter many curtailments before their wind projects become uneconomic. In Texas the 2006 wind data shows that the coincident wind maximum power was only 85% of the installed wind capacity. As the geographic area is increased, the probability of having all wind generation at Pmax or even at a real high percentage of Pmax level goes down. Would you want to build transmission that is never used? I think the economic optimum (lowest cost energy) occurs for transmission capacity being a little less than the total sum of all wind Pmax in an area.



I understand what you say.

But … Wind enthusiasts argue that the wind is always blowing somewhere. They argue that the reason we are seeing large intermittency for all wind farms on the Eastern Australian grid is because the area covered by the grid is not large enough and we need to consider a grid connecting all of Australia. They argue we need to link in Western Australia and have wind farms along the southern coast line.

That is fine in theory. But when the wind is blowing in Western Australia and not blowing in Eastern Australia, we need to be able to transmit all the power being generated in Western Australia to Eastern Australia. So we need transmission capacity to for the maximum power output. I recognise I am exaggerating to make my point clear.

Gene, I just want to check that you are not saying the $15/MWh figure is wrong, you are just suggesting it is not as conservative as I suggested. Is this correct?

Also, could you comment on whether $15/MWh is a reasonable rough figre to use for my solar thermal ‘baseload’ power stations at average 2000 km distance from the load centres?


Peter, I think Gene is right. Remember when you are building an EHV transmission line they run from point A to point B. So you are only servicing the wind farms that are connected to that line. The wind may “always be blowing somewhere” but it is unlikely to be blowing at >15 m/s everywhere in the area of connection and some turbines will be down for maintenance. The probability of getting 100% from all the connected wind farms at the same time is very small so it makes no sense to “over-build” the line when it is rarely going to be used. On the rare occasions it does happen then the wind power can be curtailed to avoid the line tripping. This is what I think AEMO will do.



I do understand the part of Gene’s reply that you have reitterated, and I did state that in my reply.

Wind farm advocates argue that the wind is usually blowing somewhere. However, there are times when it is not blowing anywhere where there are wind farms are connected to the grid. We see that all over the world. So if it is blowing full speed at Esperence and nowhere in the eastern states, we can only get as much power as the tranmissions line can carry. I do understand the point Gene and you made about what is a rational and cost effective capacity of transmission to build. But what this means is that wind power can never generate more than say 85% of its installed capacity. So, if I want to replace 1 GW of coal with 1 GW of wind and gas, I need to build about 1.2 GW of wind capacity AND 1 GW of gas. So it is even more costly and uses even more land. Leave aside the capacity credit argument for the moment.


Peter I think that is right. For a group of wind farms in a single region connected to the same transmission line you probably won’t get more than 85% of the nameplate capacity at any one time – even in Esperence. Plus the electricity from the wind farms in Esperence will go to meet demand in Esperence first before any surplus comes across to the eastern states so the amount you get on the interconnector will depend on the total generating capacity and load in the region.

In any event the interconnector would be sized based on the anticipated power flows between the regions not specifically for the wind power.

I know we disagree about the capacity credit for wind, but when assessing power needs from various generators the system operator looks at the whole network generating capacity, including the size of the interconnectors, and the anticipated loads so really the concept of 1 GW of wind replacing 1 GW of coal probably doesn’t make sense. It is just a metaphor not an installed reality.



We are talking at cross purposes. You are talking abot optimising the grid and the investment in it. I am looking at a very simple analysis of replacing coal fired power stations with substitute options. I am seeking the cost per kWh for transmission for wind and solar. We need to make simple assumptions. We are not at the stage of optimising.

By the way, I disagree with this point: “For a group of wind farms in a single region connected to the same transmission line you probably won’t get more than 85% of the nameplate capacity at any one time – even in Esperence”. We commonly get the all the wind power generating at full capacity in a region. We also commonly get a whole region generating zero or near zero. If you watch this site for example you will see times when the wind power is running at full capacity. You will also see times when the wind ids doing everything wrong – like out put rapidly decreasing as the demand rapidly increases thus exaserbating the problem of trying to bring on back up generators to take up the slack.

Regarding the region in question using most of the power first. I disagree with that too. The demand in a region such as Esperence or anywhere else for that matter is completely negligible compared with the amount of wind power that is being proposed to make a major contribution to our grid. If you say that wind power will not be able to make a significant contribution, then we would be in agreement on all points.

So, back to the main question: $/MWh for transmission for huge amounts of wind power and solar power to replace coal as coal is decommissioned. Just a simple figure. Martin do you disagree with the $15/MWh Gene suggested as a ball park figure based on the assumptions Gene used? Do you disagree with the assumptions. If so, what figure would you suggest and how is is it calculated? What about for solar thermal with average distance 2000 km – ie 4 times the assumed transmission line length for wind but with 3 times the capacity factor?


I have another question that someone might be able to help me with. It concerns CO2 intensity factors for sent out electricity, averaged across Australia for four types of generation: black coal, brown coal, oil and natural gas. Below is a summary of my posisiton at the moment:

I have not been able to obtain Australian average CO2 emissions factors for the generation technologies cited in the ABARE (2007) projections of electricity supply. So I have attempted to calculate them for the purpose of this simple comparison.

[b]ABARE + DCC[/b]

Below is an example calculation of sent-out emissions intensity for electricity generated from Black Coal

From ABARE (2007), Table I:

Electricity sent out = 518.3 PJ
Black Coal consumed = 1,374.6 PJ

From DCC NGA Factors (2009), Table 1 and Example 1:

Emissions factor for burning black coal = 88.4 kg CO2-e/GJ = 88,400 t CO2-e/PJ

Emissions intensity for electricity (from black coal) = 1374.6 x 88,400 / 518.3 = 234,448.5 t CO2-e/PJ

Convert to t CO2-e/MWh:

234,448.5 x 3600 / 1,000,000,000 = 0.844 t CO2-e/MWh

The calculations for the four fossil fuel technologies yield the following emissions factors (in t CO2-e/MWh sent out):

Technology Emissions intensity
(t CO2-e/MWh sent out)
Black coal 0.84
Brown coal 1.20
Oil 0.78
Natural gas 0.49

These figures, especially natural gas, seem to be too low compared with other apparently authoritative figures (see below).

[b]NSW GGAS Fact Sheet, Nov 09[/b]

Click to access FS-Comp-PoolCoeff-Nov09.pdf

The CO2 emissions intensity for NSW electricity (sent out) in 2008 was 0.983 t CO2-e/MWh. This include electricity generated by black coal, hydro and natural gas. Because the emissions from hydro are zero and the emissions from natural gas generation are about 0.7, it follows that the emissions from coal must be greater than 0.983. Since about 6% is generated by hydro and 10% by natural gas, a rough estimate would put the emissions from black coal generation at about 1.05 t CO2-e/MWh.

ACIL-Tasman, 2009, “Fuel resource, new entry and generation costs in the NEM”
Table 18 to 22 Emission factors and intensity for existing and committed

Click to access 419_0035.pdf

The average emission factors for the existing power stations in NSW, Qld, SA, Tas and Vic are as follows (in t CO2-e/MWh sent out):

Brown Coal 1.32
Black Coal 1.00
Natural Gas 0.73

The ACIL-Tasman figures appear to be the most rigorous analysis of the CO2 emissions intensities and the best documented. So I shall use these emissions intensities until I find a better source.


Well, Peter, the whole idea with wind is to spread it over such a large area that the average wind creates a reliable base load source of power. Thats the only way wind can succeed on a large scale to replace coal. The scenario I was envisioning is that the midwest US has wind all the way from Canada to Mexico. There would be a north south set of transmission lines connecting those wind farms together. However the transmission lines from the central US to California would not need to have the capacity of the wind CA had commited to in the midwest. Lets say that CA built half the transmission capacity of the wind they owned in the midwest. They would load those lines from the midwest to CA as they would from the power of a remote coal plant. However the average power level will only be about 1/3rd the wind capacity owned. So they build their line to be half loaded at the 1/3rd wind level and then when wind runs at 2/3rd output (this is the entire midwest) which would be rare for wind to be higher than this over such a large region, so that they could take most of the power from most of the wind most of the time. The excess would be sold to the eastern US. By having an interconnection to the eatern US, when the wind CA owned in the mid US was near 0, they could hopefully purchase power from the eastern US and from the Texas coastal area. This is how the wind is supposed to be made reliable according to Jacobson, by covering a large enough geographic area so that there is always wind blowing somewhere. I agree with you that it will sometimes not be blowing anywhere and this is the problem with wind.
Concerning the economics, the more transmission you build, the more costly it will be. If you wanted twice the transmission I was recommending, then the cents per kWh would be 3 cents per kWh rather than 1.5 cents per kWh. The only reason I was suggestion we optimize the cost is because that is always the way the utilities have done it in the past, so that cost to the customer is always as low as possible. However its true that some utilities do invest in transmission more than others, such as TVA, AEP, and CPS tend to build stronger transmission systems than other companies. I think in the end if you build a transmission system in Australia, and some wind developer senses there is an opportunity to make some money, they will install wind even though there is not enough transmission to fully accommodate them. Possibly Australia has rules that prevent them from connecting to the grid. Absense of these rules, the wind guys will tend to overbuild and you will wind up with a system with more wind generation than there is transmission to support it if the economics work out. Its also posisble that you will nave no wind that is economiic, i.e. not competetive with coal and there will be little wind development.


The idea of an equal amount of wind replacing an equal amount of coal is false. If wind has a 33% capacity factor, you would need to install at least three times as much wind as coal capacity. A loss of load probability study would also show that to achieve the same reliability for the total coal fired system you would need to add some gas peaking or quick start generation to the wind powered system. It could be made to work. To get all the costs would require a careful design analysis of the totat system with many simulations. The wind locations and amount of transmission are variables. There is no single best answer. Develop several scenarios and look at the cost and performance of all of them to decide which one looks best is the right way to do it.


Hi Gene,

Thank you for this further explanation. For the very simple comparison I am doing, I am going to use $15/MWh for transmission cost for wind.

Would it be reasonable (ball park) to use the same figure for solar thermal assuming average transmission line length of 2000 km and 90% capacity factor for the solar generators (with sufficient storage as per NEEDS report, this storage capability forecast to be achievable by 2020)?


Ref: #37986

Yes, I recognise what you say. What I am trying to do in a simple analsysis should be handled in a complicated modelling study. However, in the discussions with Neil Howes and Alexei back in July, in a moment of weakness, I did agree to attempt a very simple comparison. That is what I am trying to do now.

I agree that wind capacity does not replace coal capacity. My simple analysis assumes decommissioning black coal at the rate of 1GW per year and brown coal at the rate of 0.4GW per year. This is very fast and probably not achievable without an enormous government buy back like “cash for clunkers”. However, that is my underlying assumption. I have to replace the lost energy. I conisider the BAU option (ie no decommissioning of coal) and five other options. The options are a simple mix of generating technologies that can provide the power, on demand, that the coal fired plants would have provided if not decommissioned. One of the options is Wind + OCGT + CCGT. 1GW of coal is replaced by 1GW of wind + 0.5GW CCGT + 0.5GW OCGT. Wind provides 30% of the energy deficit and the OCGT and CCGT make up the difference in equal proportions.

I stress, this is an extremely simple analysis. I recognise what is involved in doing the analysis properly, although I do not have the capability to do it properly.

Once I’ve got the draft paper to a suitable level I will ask for a volunteer to have a look at it before it is posted on the web site. I am still feeling pretty concerned about putting up such a simple analysis as this and may yet not go ahead. You are not the only person warning me not to post it.

The benefit of it might be that if those on this web site can help me knock it into shape it might help the Government and Opposition find a better way forward than the CPRS (Cap and Trade legislation) that has just been rejected b the Australian Senate. To me the message is starkly clear from the analysis. However, if the analyses gets sunk it could do as much damage to credibility as what Jacobson put up in New Scientist.

I am listening to yours and Martin Nicholsons’ advice.


Concerning transmission for solar, its probably not the same energy cost as for wind. I would expect the solar to be more easily located closer to the load centers making it a lower energy cost for transmission. In California the roof toppers would say that no transmission is needed for their solar power. Centralized solar is probably what you have in mind. What if the solar and wind share the same transmission? Then the cost analysis gets more complicated. I guess for your needs I would size the transmission to match the solar power that is delivered. A solar farm that has storage will deliver a lower power level for a longer time. Since you have used $15 per MWh, I would adjust that number based on the distance and based on the capacity factor. Scale the 15 to the new length for solar compared to your assumption for wind distance. Then I would ratio the capacity factors of wind and solar to get the energy cost of solar. I.e. the solar transmission cost might be (15$/MWh for wind)(length of line to solar/length of line to wind)(capacity factor of wind .33/capacity factor of solar .25?). As the capacity factor of solar goes up due to storage, the energy cost of transmission goes down. So choose your solar model to get the transmission cost.


In that last posting I forgot that I had installed a lower transmission cost for wind. We need to go back to the original calculations. Lets assume $2/w for 1000 miles for a 1000 MW 345 kV line that costs $2 million per mile. Lets size the solar MW peak power to the same transmission line capacity. The installed cost of transmission is $2/w or $2million/MW. Financed at 5% interest for 30 years is an annnual cost of (2e6)(.05)(1.05^30)(1.05^30-1) = $130,000. Lets say that the solar has a 100% capacity factor with storage. Then the energy cost would be 130000/8760 = 14.8 $/MWh. However if the solar had a capacity factor of 50%, then the transmission cost would be $29.7/MWh, and if it had a 25% capacity factor the transmission cost would be $59.4/MWh. Scale the cost linearly with distance. We assumed 1000 miles in this example.


Hi Gene,

Thank you for this. Thats great. I’ll go with $15/MW for my solar power station also. That is about half what the calculation would come out to be. My assumptions are:

1. 2000km average transmission line length

2. 90% capacity factor for my solar thermal plants with storage (as per NEEDS forecast for 2020)

3. No sharing of transmission with wind farms (solar are NE of the main load centres while wind farmes are south and west of the main load centres.

4.. The solar power stations are 250 MW each and there are 100 of them dispersed over an area 1000km by 3000km. The reason is to put them in the high insolation areas and they are dispersed to minimise the loss of generating capacity when there is widespread cloud cover.

So, if I upped your foigure for 1000km to 2000km I’d increas the figure for solar from 14.8 $/MWh to $29.6/MWh. But 15 will be good enough for what I am doing, and I rather underestimate than over estimate. I suspect the costs of the solar power stations are hugely underestimated.


Yes, Good point That’s a woops. But not as bad as when NASA missed Mars with one of its lander missions because they’d mixed km and miles in one of their calculations :)

Now that I understand the basis of the estimate, I’m am still leaning to assuming $15/MWh for transmission for both wind and solar thermal. It is close enough for the very rough comparison I am making, and it is simpler.

Thank you Gene. I’ve learnt a lot and I very much appreciate your help and guidance.

Barry, you have a fantastic team contributing on the BNC web site.


I don’t buy Scientific American any more because it has changed from being objectively scientific, moving instead to the warm and fuzzy politically correct end of the spectrum. Consequently many of it’s articles are written by science writers rather than the experts. In particular I don’t agree with the magazine’s anti-nuclear stance as typified by the article written by Jacobson who is neither a nuclear physicist or nuclear engineer.


“For fossil fuels, should we count the carbon footprint of Operation Iraqi Liberation?”

Well given that some antinuclear studies have attempted to charge nuclear energy with the carbon burden from a potential nuclear war, why not?


Well given that some antinuclear studies have attempted to charge nuclear energy with the carbon burden from a potential nuclear war, why not?

On that primciple, we should also include all the carbon emissions from the whole Pacific theatre and the Eastern Front in WWII.


@Moitoza: you wrote

without distancing quotes the words: Operation Iraqi Liberation, ie the invasion of a sovereign country as part of a war of aggression conducted by two prima facie elected war criminals in the USA and UK. I assume you approve of this, inasmuch as you seem to imply (?) that counting the carbon footprint of that aggression would be ridiculous, given the benefits of the aggression. For example, several hundred thousand deaths, and so on.

This is quite humorous, I agree, given the centrality of Iraqi petroleum reserves and hence increased C02 emissions to the venture. But it will not be the humour you intended.



I assume you approve of this, inasmuch as you seem to imply (?) that counting the carbon footprint of that aggression would be ridiculous, given the benefits of the aggression. For example, several hundred thousand deaths, and so on.



The Price-Anderson Nuclear Industries Indemnity Act partially indemnifies the nuclear industry against liability claims arising from nuclear incidents. The Act establishes a no fault insurance system in which any claims above the $10 billion would be covered by the federal government. Investors are unwilling to accept risks of nuclear energy without some limitation on their liability. If it is safe, withdraw the the Price Anderson Act. Then see who is willing to invest. It no one will why would we use federal money? Nor is it carbon free. There are multiple issues, Consider Iran. Nuclear profiliferation. Waste. And there are non carbon ways to get all of our energy. Conservation comes first. Locally produced sustainable energy would be next. Energy Secretary Chu is a well educated and intellegent person. However, as he is emotionally invested in the nuclear area, aas many posting here appear to be, he would best recuse himself on this matter.


Anand Keathley – American antinuclear activists love holding out the Price-Anderson act as some sort of proof that nuclear energy is unsafe. I always ask if it covers Canada, France the UK, and Japan. It does not of course and nuclear energy has developed in those countries without its benefits.

The other thing is of course, to date no accident that has even come close to 10 billion USD has occurred, nor is one ever going to, given the types of reactors and the way they are operated. But sure if I was an American, I would be happy to see the end of that stupid act, it has served its purpose, and it’s time is over. If only to pull the rug under stupid arguments like yours.

Nuclear energy is as carbon free as any source of energy can be, this red herring has been so thoroughly disproved and ridiculed, I’m surprised that someone would still try to bring it up. There are no sources of energy that are carbon-free using the same criteria applied to nuclear in this matter.

There is no ‘waste issue’ – there are several solutions, that meet every criteria the antinuclear movement can throw at them. They are now reduced to blocking the very things they were demanding, in an attempt to keep the issue alive. The farce over Yucca mountain, has done an immense amount of damage to the antinuclear movement in the US, in the eyes of the common citizen there, more than we could have ever dreamed of doing on our own.

Nuclear proliferation is not a consequence of nuclear energy. This is rubbish that depends on public ignorance and a shared name. They are not linked in any real way, and I challenge you to show otherwise.

Conservation and locally produced sustainable energy will never meet the needs of our civilization, and the fact that you call for them shows only that you do not understand energy at all.

It would be wise if you obtained some grounding in the subject before parroting the lies of others – it would make you look like less of a fool


Anand said:

If it is safe, withdraw the the Price Anderson Act. Then see who is willing to invest.

Shorter: if something does go wrong, and the company running the plant wants to default or needs to, that’s OK with you. The industry as a whole needn’t step in. That would make it more attractive because nobody would have to worry about what others in the risk pool were doing and could always default.

What you miss is that Price Anderson makes all operators effectively liable if anyone causes any damage that they personally can’t cover. That means that the industry as a whole gets an incentive to ensure they all do the right thing and that anyone thinking about cutting corners is pulled back into line.

That is one reason (though not the only one) why in the US there has never been an accident like Chernobyl and the 1957 providions have never been tested.

At the risk of pointing out the obvious, if, for the sake of argument, there were a catastrophe occasoining damage of say, $US1trillion, how relevant do you think the state coverage of that extra $990 billion would be?

Do you think that the operators would pay, or declare bankruptcy first? I’m guessing they would declare bankruptcy, and then nobody would get very much of anything, including their power.

Making them pay a premium for an event that is not going to happen would simply be a way of pricing nuclear power out of the market and throwing the right to supply to coal, who, despite the hysteria over nuclear power, kill more people every day than nuclear power has yet killed in all its history and generates more uncontrolled nuclear waste.

How that helps anyone who needs help is hard to see.


No power plant, (or much of anything else,) can be built without insurance. No insurance company will insure a privately owned nuclear power plant without the Price Anderson Act to cover their ass. In Europe the Nuclear power plants are state owned so there is no comparison.


In my country, all large and risky activities approved by the national government (war, hydraulic dams, industrial plants, nuclear plants, etcetera) are backed up by instruments similar to the Price Anderson Act.

This is as it should be – the government approved the activity in the first place and so is responsible for providing insurance against losses arising from the conduct of that activity.

In the case of nuclear energy, plant owners relieve the government of most of the insurance burden by taking on responsibility for all of the more probable consequences. End of story.


Gene: But surely it CAN work if we recognize that private and public institutions must work together. to save the nation.

We’re all, just now, in the same leaky boat. Problem is that some passengers are bailing water INTO the boat while most of us are trying to bail it out.



“Let’s parse this. By reliability of the coal plant, I assume in this context that they mean its capacity factor (rather than unscheduled outages), which would be around 85% of peak output. Now, wind in excellent sites has a capacity factor of ~35%, so the yearly-averaged power of a hypothetical 10 GW peak wind array of 13-19 farms would be 3.5 GW. Now, following their statement, 33% of 3.5 GW — that is, 1.15 GW or ~12% of peak capacity — would be available 85% of the time. Or, to put it another way, we’d need to install 10 GW of peak wind to replace the output of 1.4 GW of coal? Is that what they are saying? Did they cost this? (hint: no, see below). Perhaps someone else can confirm or reject my interpretation of the statements on p19 of the tech paper.”

Barry: I have a question about capacity factor or a possible ambiguity in its use. In what you say above, capacity factor seems to mean two things: the ratio of yearly averaged power to nameplate or optimum AND “reliability” in the sense that 85 % capacity factor means “available 85% of the time.”

I have seen others define capacity factor not as the ratio of average power to nameplate but as a metric measuring how often the plant is operating at 100%: Robert Bryce in his book Power Hungry (a book you should review, btw) defines it this way. They are not the same, are they? (self doubt)

Bryce by the way also seems to confuse capacity factor with what we might call base load factor: as in your above number of 1.15 GW, that amount of power available nearly always.

Bryce cites Peter Lang favorably.

off point: Bryce is a libertarian (for the most part) whose view is that capitalism (the only practical way to run the world for him) is trending toward nuclear and natural gas but that the trend is slow and we will be reliant on fossil fuels for many, many years. He’s agnostic about AGW, which is convenient for him. Because if AGW turns out like Hansen says, this guy is basically saying “we’re going to have to adjust.”

it’s a disturbing book for many reasons, filled with insights, but with a potential for monumental apologetics.


greg, a key thing to remember is that, in simple terms, capacity factor = availability factory x demand. For coal, nuclear and gas, their availability factor is determined predominantly by scheduled outages, for standard equipment maintenance, refuelling etc. For plants operated in baseload, demand is nearly constant (i.e. that coefficient is close to 1). A capacity factor for nuclear power might be 90% over a year, assuming 1 month out of each year for refuelling and scheduled maintenance. For the other 11 months, its availability factor is closer to 99% — SCRAMs are what takes this below 100%.

Wind is quite different. It’s availability factor is determined by when the wind is blowing, in addition to scheduled maintenance and, for a wind farm of many turbines in total, the occasional failure of an individual turbine. The engineering availability factor might be in the order of 99% for wind too, but the wind ‘fuel’ is quite a different matter. Sometimes it will be blowing strong enough to deliver near 100% of nameplate capacity, other times it will be 50%, or 20% or whatever. Sometimes, when it is becalmed or too windy (such that the turbines are shut off to avoid damage), it will be 0%. On average, over a year, it will be about 35% in good sites. But this power is not ‘dispatchable’ — it cannot be guaranteed (without energy storage), since the wind is fickle.

What the WWS study is saying is that for a widely geographically dispersed set of wind farms, you can guarantee, to the equivalent of an 85% availability, a ‘capacity credit’ of about 12%. So, in rough terms, the 12% capacity credit for wind is the equivalent of the 85% capacity factor of a coal-fired power station. Make sense?


I get it.

Would it follow that Bryce’s definition of capacity factor would work for nuclear and coal but not for wind since the latter’s coefficient is not close to one.


Bryce’s definition of capacity factor works for coal, gas and nuclear as it stands, and works for wind if it is called ‘capacity credit’. The coefficient is much less than 1 for wind because it is not dispatchable – chicken and egg.


The above discussion about coal reliability is overly simplified. We need to make a distinction about annual peak, weekends, and low load periods of the year. The coal plant reliability is determined mostly by the FOR, forced outage rate, which could be as good as 95% (5% FOR) when the coal plant is needed most, during the peak load periods. Many maintenance problems can be deferred to the weekend when the load is less. This type of problem usually does not greatly affect the reliability. Then scheduled maintenance is scheduled for light load periods of the year when the plant is not needed. When you do a loss of load probability study, you will find that the greatest loss of load is during the peak load periods, not the lighter load periods. A plant failure during the lighter load periods usually has little consequence, provided the network is electrically stable for the loss of the largest generation within a geographic region. The annual capacity factor is mostly determined by demand for a coal plant. Coal can go into load following frequently and is dispatched after natural gas and before nuclear, which is even more base loaded than coal. Wind generation can cause gas and coal plants to be backed off because wind had a lower incremental energy cost than either gas or coal. Therefore adding more wind to a region will cause the capacity factor of coal to drop a little, especially when the wind runs during light load periods, which is does frequently. However because coal plants are difficult to dispatch they cannot be run back very far to accomodate wind. Because of the unpredictable nature of wind there must be kept on line a certain amount of gas and coal in the event wind is not sufficient. But there is only a certain amount you can swing gas and coal generators. Therefore as more and more wind is added it becomes more difficult to dispatch the total set of generators. Its possible to have some stablity problems with the network as wind is swinging from low to high levels. As you keep adding more and more wind you will reach a point where wind has to be dumped even if there are no transmission limitations. This is because the gas and coal generators cannot be swung enough to accomodate all the wind. Therefore wind is going to have an upper limit, probably no more than about 30% of the total energy. The only way to simulate the network to see how it work is in an hourly simulation model. That model can also be a montecarlo model considering random failures of both generators and line and even wind variability. Every once in a while the hourly model will run into difficulties that require dumping load. This is the only correct way to model the system.


I have this to say about Nuclear Power. Imagine BP running one of those. Not scared? Then you are not paying attention. All for profit corporations require ever increasing profits. That leads to cost cutting on all things including safety. It does not matter if it is possible to run one safely. Sooner or latter some corporation will do what they all do, skimp on something they should not have, bride an inspector or any one of a number of things to save a buck. And when they do…..
So, if we want a place for or Grandchildren to live we need to find a way to do it with sustainable energy. You may find many ways to say it can not be done. But I ask you, do you really think it is optional?


Anand Keathley – Yes, by all means, we can all go along with not poisoning our children. But the question that needs to follow is: will wind and solar energy help us do that? Will sustainable energy schemes reduce our dependence on coal or gas fired electricity?

The answer is no. All one has to do is look to Europe, which has installed thousands of wind turbines and solar panels over the past two decades. Not one coal fired electricity generating plant has closed due to the introduction of these new generating sources. In fact, European nations are building 50 brand new coal-fired generating plants over the next decade. They are also scaling back wind energy development and the rich incentives required to erect it. Why does anyone expect a different outcome anywhere else?

The number one lie: XYZ wind farm will supply electricity for 5,000 homes. The truth is that all the wind turbines in all the world can’t run a toaster, let alone a home, on their own. It is a lie that is repeated in virtually every news story on wind or solar development. Intermittent energy sources like wind and solar must be paired with a fossil fuel generating plant to produce the steady and reliable stream of electricity your toaster needs to run properly.

Many will suggest it is a worthwhile gamble—that doing something is better than doing nothing. But this is a trap. Doing the wrong thing is worse. Much, much worse. For we are robbing ourselves of the dollars that should be invested in real energy – nuclear energy – not frittered away by making the investors in renewables schemes wealthy.



This is well explained for Amanda.

Renewable energy proponents will respond in one of two ways:

1. reasonable people with an open and enquiring mind will think perhaps they have been misled. They will then start to dig further, using properly enquiring processes to see what is the truth about the claims for renewable energy.

2. The others have closed minds. They are proponents of renewable energy for other reasons, not rational reasons.


Amanda said:

have this to say about Nuclear Power. Imagine BP running one of those. Not scared? Then you are not paying attention.

This is simply a spray. You can’t compare the risk in a deep sea drilling operation with megatonnes of dense liquid and a seriously engineered plant which can be gone over with the proverbial fine-toothed comb.

You advance no substantive claim and simply invitye under-informed people to envisage the worst possible thing as if it were technically possible and likely.

The fact is that right now, BP and other companies are in charge of far more prospectively risky technologies with far thinner margins for error that really do kill people on a large scale all the time. You want people to look elsewhere. Whatever you say in theory, in practice, no nuclear = more coal and gas, both of which are far more dangerous day in and day out than nuclear. Do a body count of the miners killed in mining incidents alone in China alone since 1970. Then add in the progressive asphyxiation of people along the transport chain to the coal plant. Then add in those asphyxiated and poisoned, including by radioactive waste and then add global warming and acidication of the oceans and then tell me why nuclear is a comparative worry.

So, if we want a place for or Grandchildren to live we need to find a way to do it with sustainable energy. You may find many ways to say it can not be done. But I ask you, do you really think it is optional?

The answer is that nuclear power is sustainable whereas renewables are not — at least, if we are talking about renewables at a scale needed to foreclose coal and gas on a world scale.

Until someone can show that some offically renewable energy source capable of supplanting coal and gas is commercially feasible, the demand for renewables is the demand for business as usual with an utterly unimpressive figleaf. It’s coal and gas in drag with green activists pretending this says nothing about their underlying cultural preference.

Well that doesn’t wash. As Gene Preston notes, your demands can only be realised by using fossil fuels less efficiently and probably in greater volume in some settings. Your proposals subvert not only the interests of the grandchildren but the grandparents too. I’m outing you and your fellow travellers as closet fossil fuel advocates, as unwitting purveyors of greenwash.

It’s not too late. Work it through. How does your advocacy contribute to the options available to societies wishing to deploy the reliable industrial scale energy that is fundamental to contemporary life? If it prejudices the choice in favour of fossil fuels, then surely you must modify your advocacy so that it does the opposite? Simply saying “well we will have to find a way without nuclear” is not tenable unless there is a way without nuclear and at the moment, there simply is no such option available.


You’re welcome Greg …

I’m thinking of making it into a bumper sticker, to place alongside my other sticker on clean energy.

I am thinking of how to make a smoking coal plant look like a hippy-style female impersonator … ;-)

I’ll have to get my creative juices flowing!


I just came across this and thought some might be interested:

Bill Hannahan said:

Stephen, when people are freezing to death in their homes during a severe cold snap due to an extended power failure you can console them with the knowledge that the stationary windmills all around then are technically available.

Jacobson’s paper makes this claim;

“It was found that an average of 33% and a maximum of 47% of yearly averaged wind power from interconnected farms can be used as reliable, baseload electric power….”

This is what the review comment is about, not windmill availability.

Jacobson wrote; “Nevertheless, because coal plants were shut down for scheduled maintenance 6.5% of the year and unscheduled maintenance or forced outage for another 6% of the year on average in the United States from 2000 to 2004, coal energy from a given plant is guaranteed only 87.5% of the year, with a typical range of 79%–92% (North American Electric Reliability Council 2005; Giebel 2000).”

Note that I used the same database he uses to show that his conclusion is not valid. The reliability of fossil fuel supply is high, so the reliability of fossil based electricity is nearly equal to plant reliability.

Jacobson wrote; “”Firm capacity” is the fraction of installed wind capacity that is online at the same probability as that of a coal-fired power plant.”

This is where the authors have redefined reliability. First they use the term, “Firm capacity,” and then when they write their conclusion it is “reliable.”

Imagine that someone invents a cold fusion generator that is very cheap to mass produce, but can only be operated at rated power for 1 hour in every 10 hours. The “Firm Capacity” of these units is only 10%, less than one fourth the 45% Jacobson claims as the “Firm Capacity” of the windfarms.

A utility would buy enough units to cover its highest demand day, and have a totally reliable grid year round with no backup plants, no storage and no additional transmission lines required. That is because each unit can be scheduled well in advance and dispatched as needed. These are the qualities that give an energy source reliability, and they are not present with wind farms, even if they are interconnected. “Firm capacity” is not an indication of, or correlated with, or equivalent to reliability, except at the end points of 0% and 100%.

Stephen, do you think “Firm Capacity” is a better measure of reliability than IEEE 762?
Jacobson’s entire paper hangs on the assumption that “firm capacity” and “reliability” are equivalent and interchangeable, in direct contradiction of this example, the examples in the comment, common sense and industry standards.

Maintaining grid reliability is a matter of life and death.

People who try to reduce grid reliability to a word game reveal more about themselves than they reveal about our energy options.

So, your unanswered questions are;

1… Jockeying fossil plants to load level wind means many more thermal stress cycles, higher maintenance cost for those plants and higher emissions. It also reduces thermodynamic efficiency. Where are these costs included in your academic wind analysis?

2… How much hydro power would we have built if it only generated power while it rained?

3… Would it be reliable baseload power if we interconnected those rain only hydro plants? It’s always raining somewhere, right?

4… What would the transmission system for that cost?

5… How much money do you think we should be spending on R&D to make reliable, clean, safe, dispatchable energy that is cheaper than burning coal?

6… What is your definition of dispatchable?

7… What is the power industry definition of dispatchable?

8… What is your definition of baseload power?

9… What is the industry definition of baseload power?

10… What does the subsidy for commercial nuclear power (not military or fusion) add up to in cents per kWh? Reference please.

11… What do the taxes paid on nuclear kWh’s add up to in cents per kWh?

You mentioned the insurance issue again. You still have 14 questions to answer on that issue.

12… What are your thoughts on the fact that emissions increased when fossil plants were forced to load level for windfarms?

13… Do you think “Firm Capacity” is a better measure of reliability than IEEE 762?


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As an engineer concerned about climate change, it often frustrates me how many “allies” in this area discredit the movement by spouting off inaccurate, overly-optimistic statements with no basis in economic reality.

Thanks for this post – it touches on a number of important points.


Having directly argued with Jacobson, even requiring assistance from the Stanford Provost for Research to get him to respond, it became clear that he’s simply a Civil Engineer who became expert in world wind patterns.

He even tried to parlay that basic knowledge into an absurd and debunked article on how many Americans would die from Fukushima fallout. He publicly demonstrated his ignorance of nuclear science and radio-biology. Sadly, he dragged a younger co-author along in his quest for full professorship, perhaps.

As a Stanford alum, I’m sorry for Jacobson’s misinformation.


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