Nuclear Renewables

Solar realities and transmission costs – addendum

Peter Lang’s ‘solar realities’ paper and its associated discussion thread has generated an enormous amount of interest on BraveNewClimate (435 comments to date). Peter and I have greatly appreciated the feedback (although not always agreed with the critiques!), and this has led Peter to prepare: (a) an updated version of ‘Solar Realites’ (download the updated v2 PDF here) and (b) a response paper (download PDF here). Below I reproduce the response, and also include Peter’s sketched analysis of the scale/cost of the electricity transmission infrastructure (PDF here).


Comparison of capital cost of nuclear and solar power

By Peter Lang (Peter is a retired geologist and engineer with 40 years experience on a wide range of energy projects throughout the world, including managing energy R&D and providing policy advice for government and opposition. His experience includes: coal, oil, gas, hydro, geothermal, nuclear power plants, nuclear waste disposal, and a wide range of energy end use management projects)


This paper compares the capital cost of three electricity generation technologies based on a simple analysis. The comparison is on the basis that the technologies can supply the National Electricity Market (NEM) demand without fossil fuel back up. The NEM demand in winter 2007 was:

20 GW base load power;

33 GW peak power (at 6:30 pm); and

25 GW average power.

600 GWh energy per day (450 GWh between 3 pm and 9 am)

The three technologies compared are:

1. Nuclear power;

2. Solar photo-voltaic with energy storage; and

3. Solar thermal with energy storage

(Solar thermal technologies that can meet this demand do not exist yet. Solar thermal is still in the early stages of development and demonstration. On the technology life cycle Solar Thermal is before “Bleeding edge” – refer:

This paper is an extension of the paper “Solar Power Realities” . That paper provides information that is essential for understanding this paper. The estimates are ‘ball-park’ and intended to provide a ranking of the technologies rather than exact costs. The estimates should be considered as +/- 50%.

Nuclear Power

25 GW @ $4 billion /GW = $100 billion (The settled-down-cost of nuclear may be 25% to 50% of this figure if we reach consensus that we need to cut emissions from electricity to near zero as quickly as practicable.)

8 GW pumped hydro storage @ $2.5 billion /GW = $20 billion

Total capital cost = $120 billion

Australia already has about 2 GW of pumped-hydro storage so we would need an additional 6 GW to meet this requirement. If sufficient pumped hydro storage sites are not available we can use an additional 8GW of nuclear or chemical storage (e.g. Sodium Sulphur batteries). The additional 8 GW of nuclear would increase the cost by $12 billion to $132 billion (the cost of extra 8 GW nuclear less the cost of 8 GW of pumped hydro storage; i.e. $32 billion – $20 billion).

Solar Photo-Voltaic (PV)

From ‘Solar Power Realities’ :

Capital cost of PV system with 30 days of pumped-hydro storage = $2,800 billion. (In reality, we do not have sites available for even 1 day of pumped hydro storage.)

Capital cost of PV system with 5 days of Sodium Sulphur battery storage = $4,600 billion.

Solar Thermal

The system must be able to supply the power to meet demand at all times, even during long periods of overcast conditions. We must design for the worst conditions.

We’ll consider two worst case scenarios:

1. All power stations are under cloud at the same time for 3 days.

2. At all times between 9 am and 3 pm at least one power station, somewhere, has direct sunlight, but all other power stations are under cloud.


The average capacity factor for all the power stations when under cloud for 3 days is 1.56 % (to be consistent with the PV analysis in “Solar Power Realities”; refer to Figure 7 and the table on page 10).

The capacity factor in midwinter, when not under cloud, is 15% (refer Figure 7 in “Solar Power Realities”).

Scenario 1 – all power stations under cloud

Energy storage required: 3 days x 450,000 MWh/d = 1,350,000 MWh

Hours of the day when energy is stored (9 am to 3 pm) = 6 hours

Average power to meet direct day-time demand = 25 GW

Average power required to store 450,000 MWh in 6 hours = 75 GW

Total power required for 6 hours (9 am to 3 pm) = 100 GW

Installed capacity required to provide 100 GW power at 1.56% capacity factor (say 6.24% capacity factor from 9 am to 3 pm) = 1,600 GW.

Total peak generating capacity required = 1,600 GW

If the average capacity factor was double, the installed capacity required would be half. So the result is highly sensitive to the average capacity factor.

Scenario 2 – at least one power station has direct sun at all times between 9 am and 3 pm

One power station provides virtually all the power. The other power stations are under cloud and have a capacity factor of just 1.56%.

Energy storage required for 1 day = 450,000 MWh

Hours of the day when energy is stored (9 am to 3 pm) = 6 hours

Average power to meet direct day-time demand = 25 GW

Average power required to store 450,000 MWh in 6 hours = 75 GW

Total power required = 100 GW.

The capacity factor in midwinter, when not under cloud, is 15% (refer Figure 7 in “Solar Power Realities”).

Installed capacity required to provide 100 GW power at 15% capacity factor (60% capacity factor from 9 am to 3 pm) = 167 GW.

But the clouds move, so all the power stations need this generating capacity.

To maximise the probability that at least one power station is in the sun we need many power stations spread over a large geographic area. If we have say 20 power stations spread across south east South Australia, Victoria, NSW and southern Queensland, we would need 3,300 GW – assuming only the power station in the sun is generating.

If we want redundancy for the power station in the sun, we’d need to double the 3,300 GW to 6,600 GW.

Of course the power stations under cloud will also contribute. Let’s say they are generating at 1.56% capacity factor. Without going through the calculations we can see the capacity required will be between the 1,600 GW calculated for Scenario 1 and the 3,300 GW calculated here. However, it is a relatively small reduction (CF 3% / 60% = 5% reduction), so I have ignored it in this simple analysis .

So, Scenario 2 requires 450,000 MWh storage and 3,300 GW generating capacity. It also requires a very much greater transmission capacity, but we’ll ignore that for now.

Costs of Solar Thermal with storage

NEEDS , 2008, “Final report on technical data, costs, and life cycle inventories of solar thermal power plants” Table 2.3, gives costs for the two most prospective solar thermal technologies. They selected the solar trough as the reference technology and did all the calculations for it. The cost for a solar trough system factored up to 18 hours storage and converted to Australian dollars is:


This would be the cost if the sun was always shining brightly on all the solar power stations. This is about five times the cost of nuclear. However, that is not all. This system may have an economic life expectancy of perhaps 30 years. So it will need to be replaced at least once during the life of a nuclear plant. So the costs should be doubled to have a fair comparison with a nuclear plant.

In order to estimate the costs for Scenario 1 and Scenario 2 we need costs for power and for energy storage as separate items. The input data and the calculations are shown in the Appendix.

The costs for the two scenarios (see Appendix for the calculations) are:


Summary of cost estimates for the options considered


The conclusion stated in the “Solar Power Realities” paper is confirmed. The Capital cost of solar power would be 20 times more than nuclear power to provide the NEM demand. Solar PV is the least cost of the solar options. The much greater investment in solar PV than in solar thermal world wide corroborates this conclusion.

Some notes on cloud cover

A quick scan of the Bureau of Meteorology satellite images revealed the following:

This link provides satelite views. A loop through the midday images for each day of June, July and August 2009, shows that much of south east South Australia, Victoria, NSW and southern Queensland were cloud covered on June 1, 2, 21 and 25 to 28. July 3 to 6, 10, 11, 14. 16, 22 to 31 also had widespread cloud cover (26th was the worst), as did August 4, 9, 10, 21, 22.. This was not a a rigorous study.

Also see the BOM Solar Radiation Browse Service for March and April 2002 (the data on this site only goes up to 14 April 2002). Notice the low solar radiation levels for 25 to 30 March and 8 to 12 April 2002 over the area we are looking at. The loop animation can be viewed here.

Some comments on Future Costs?

How much cheaper can solar power be? NEEDS figure 3.7, p31 suggests that the cost of solar thermal may be halved by 2040.

How much cheaper can nuclear be? Hanford B, the first large reactor ever made, was built in 15 months, ran for 24 years, and its power was expanded by a factor of 9 during its life. If we could do that 65 years ago, for a first of a kind technology, what could we do now by building on experience to date if we wanted to put our mind to it. Is it unreasonable to believe that, 65 years later, we could build nuclear power plants, twenty times the power of the first reactor, in 12 months, for 25% of the cost of current generation nuclear power stations?

Appendix – Cost Calculations for Solar Thermal

The unit cost rates used in the analyses below were obtained from: NEEDS, 2008, “Final report on technical data, costs, and life cycle inventories of solar thermal power plants“, p31 and Figure 3.7.


Note that, although this table includes calculations for the cost of a system with 3 and 5 days of continuous operation at full power, the technology does not exist, and current evidence is that it is impracticable. The figure is used in this comparison, but is highly optimistic.


Eraring to Kemps Creek 500kV transmission line. Each of the double circuit 500kV lines from Eraring to Kemps Creek can carry 3250MW.  The 500kV lines are double circuit, 3 phase, quad Orange, i.e.2 circuits times 3 phases times 4 conductors per bundle, i.e. 24 wires per tower.  Orange is ACSR, Aluminium Conductor Steel Reinforced, with 54 strands of 3.25mm dia aluminium surrounding 7 strands of 3.25mm dia steel.  Roughly 1/3 of the cost of a line is in the wires, 1/3 in the steel towers and 1/3 in the easements required to run the line.
Eraring to Kemps Creek 500kV transmission line. Each of the double circuit 500kV lines from Eraring to Kemps Creek can carry 3250MW. The 500kV lines are double circuit, 3 phase, quad Orange, i.e.2 circuits times 3 phases times 4 conductors per bundle, i.e. 24 wires per tower. Orange is ACSR, Aluminium Conductor Steel Reinforced, with 54 strands of 3.25mm dia aluminium surrounding 7 strands of 3.25mm dia steel. Roughly 1/3 of the cost of a line is in the wires, 1/3 in the steel towers and 1/3 in the easements required to run the line.

Capital Cost of Transmission for Renewable Energy

Following is a ‘ball park’ calculation of the cost of a trunk transmission system to support wind and solar farms spread across the continent and generating all our electricity.

The idea of distributed renewable energy generators is that at least one region will be able to meet the total average demand (25 GW) at any time. Applying the principle that ‘the wind is always blowing somewhere’ and ‘the sun will always be shining somewhere in the day time’, there will be times when all the power would be supplied by just one region – let’s call it the ‘Somewhere Region’.

The scenario to be costed is as follows:

Wind power stations are located predominantly along the southern strip of Australia from Perth to Melbourne.

Solar thermal power stations, each with their own on-site energy storage, are distributed throughout our deserts, mostly in the east-west band across the middle of the continent.

All power (25GW) must be able to be provided by any region.

We’ll base the costs on building a trunk transmission system from Perth to Sydney, with five north-south transmission lines linking from the solar thermal regions at around latitude 23 degrees. The Perth to Sydney trunk line is 4,000 km and the five north-south lines average 1000 km each. Add 1,000 km to distribute to Adelaide, Melbourne, Brisbane. Total line length is 10,000km. All lines must carry 25GW.

Each of the double circuit 500kV lines from Eraring Power Station to Kemps Creek can transmit 3,250MW so let’s say we would need 8 parallel lines for 25GW plus one extra as emergency spare.

The cost of the double circuit 500kV lines is about $2M/km.

For nine lines the cost would be $18M/km.

So the total cost of a transmission system to transmit from the ‘Somewhere Region’ to the demand centres is 10,000km x $18M/km = $180 billion

The trunk transmission lines might represent half the cost of the complete transmission system enhancements needed to support the renewable generators.

Just the cost of the trunk transmission lines alone ($180 billion) is more than the cost of the whole nuclear option ($120 billion).

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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.

322 replies on “Solar realities and transmission costs – addendum”


@27 April 2010 at 8.09 Said
Mate: I’m not very technical, but even I am left wondering if some of your article above is a straw-man debunking strategies none of the renewables guys are proposing?

28 April 2010 at 8.54 Said
I don’t see how debunking something no-one ever proposed helps clarify the situation.

Critiquing a completely unrealistic, exaggerated strawman of the renewables plans does as much for the credibility of these arguments as Dr Caldicott does for her anti-nuclear cause. I’m amazed at the obfuscation from both sides.

@ 28 April 2010 at 9.47 Said:

Sorry mate but you’re the one avoiding the issues. Maybe you need to actually review an actual renewables plan, and not debunk nonsense that no-one is proposing.

@ 28 April 2010 at 12.57 Said:
Some commenter at BNC occasionally act as high level priests initiated into the arcane arts and snubbing their noses at those who aren’t. But if you wish to communicate to non-technical activists like myself and have the nuclear power debate move forward, then maybe answering those questions in an intelligible manner for the uninitiated might help.

The issues you are raising have been discussed at length in the comments on these threads. I note you’ve bookmarked the paper but haven’t yet read it. I’ve responded to your comments and question, but understand that my explanation may not have made sense to you. I’ll make another attempt to answer your question below. If this is not sufficient, can I persuade you to read the article, and the preceding articles that it build on, and also perhaps follow through the discussion on the threads as these discuss the points you are raising.

The reason for the limit analysis – that is, looking at just solar power rather than a mix of renewable energy generators – in the first instance is so we can get an understanding of the mistakes and misinformation that is being propagated by the solar power advocates.

One of the most important mistakes is doing calculations on the basis of the average capacity factor over a year. Using an average capacity factor instead of the minimum capacity factor, under-estimates the cost by a huge amount.

Here is the explanation, in layman’s language

The average capacity factors from an actual solar farm are: annual = 13%, 3 months of winter = 9.6%, the worst days in winter = 0.75%, at night = 0%.

We need electricity to be generated at the instant we demand it. To achieve this when the solar thermal plants are not generating we need either energy storage, back up generators, or a mix of other renewables (such as you proposed ).

The “Solar Power Realities” paper considered the option of all power being generated by solar power and using energy storage to supply the electricity when the sun is not shining. No one is suggesting this is a scheme that would be built (other than advocates like David Mills), but this is a way to look at the real costs of solar. You can downscale from providing all electricity to providing just 1 GW or 1MW or whatever you like. The principles apply generally. The principle is that you cannot use average capacity factors. You must look at how you will provide the power when the solar plant is generating at its minimum capacity factor.

As I mentioned, the ‘Solar Power Realities” paper looked at the situation with solar generators and energy storage. It considered two storage options: pumped hydro and NaS batteries. NaS batteries are the least cost battery option at the moment.

The “Emission Cuts Realities” paper considers a simple mix of renewable energy technologies together with gas back-up for wind power.

Lastly, let’s consider, in a really simple way for clarity, the situation with a mix of renewables to provide our power needs. We must remember that the power must be provided at the instant we need it. Let’s say we need to deliver 1GW of power on demand (just to keep this simple).

Let’s start with 1GW of solar PV. The capital cost is around $10 billion. We find we have no power at night and almost no power at some times on some days (heavily overcast). So we need to add something else to provide the 1GW power when it is demanded.

So we add 1 GW of wind power. The capital cost is about $2.6 billion. But we find the sun isn’t shining and the wind isn’t blowing.

So we add 1GW of wave power. I don’t remember the capital cost but let’s say $10 billion. But then we have times when the sun isn’t shining, the wind isn’t blowing and the sea swell is small.

We are now up to $22.6 billion

To link all these dispersed generation systems, we need a massively expensive electricity grid and we still don’t have dispatchable power (power that can be supplied when the user demands it).

So we have to add either: energy storage, or fossil fuel back up, or a dispatchable generators like biomass, geothermal or nuclear.

Biomass is expensive, requires enormous land area and has its own environmental problems.

The type of geothermal energy that Australia is attempting to develop has not been developed anywhere in the world yet. It may or may not eventuate as a commercial proposition. The world has been working on it for nearly 40 years and we have not advanced much in that time. There are still no commercial power stations anywhere in the world.

So why not simply skip all this nonsense and go straight to nuclear. The capital cost of the 1 GW would be around $4 billion, with all the impediments to nuclear remaining in place, or perhaps around $2 to $2.5 billion if the imposts were removed and we had a genuine level playing field for electricity supply.

Given that nuclear is about 10 to 100 times safer than our current electricity generating system, and is far more environmentally benign than any (including wind and solar), why don’t we just cut through all the irrational arguments and go straight to nuclear – preferably by removing all the impediments to it?


I have to laugh at the pathetic attempt by the Old Greens to find some way, any way to avoid nuclear power, They are no longer even bothering to mount their usual pathetic attacks against nuclear energy, so thoroughly have those tried arguments been debunked. But they will not give up, and desperately hope their renewable dreams can still be shown to be superior, even as they begin to see the truth.

Do you know what I think? They are afraid of nuclear energy because its acceptance will show everyone the magnitude of their error. They know that their followers will realize that they have been backing the wrong side, and as always in these cases will turn on their leaders like a pack of dogs.

And when that happens, I’m going buy beer and popcorn.


EclipseNow, let me offer a loose analogy for Peter’s limit analysis approach.

Suppose you are building a house. You have a variety of construction materials to choose from – timber, brick, steel beams, glass, tile, etc. You obviously expect to use a mix of these materials. But you can’t begin to design that mix unless you understand the characteristics of the individual materials. How strong are they? How much do you need? How much do they cost?

Peter is trying to build an energy system. On his design palette, he has fossil fuels, wind, solar, hydro, nuclear. But he can’t design with these design elements unless he understands their individual characteristics. How much power can they provide? How reliable are they? How much do you need? How much will it cost? And, in this case, how much CO2 will they produce?

To understand his design elements, Peter has done the equivalent of designing a glass house to understand the limits of using glass as a building material. He’s done the same with wood, and steel. These design exercises have probed the qualities and limits of the design elements.

He has then followed up with a further design exercise where he builds from various combinations of materials, and compared the different structures in terms of strength, cost, build time, and waste.

By analysing each renewable technology individually, he’s also thrown light on the characteristics of an integrated system. Unfortunately the wind and solar components turn out to be the equivalent of wet cardboard and cured ham, and he’s found that if you build a house out of these materials, you’re still going to need just about as much brick and steel as a normal house, if you want it to stay standing, even if you use a combination of ham and cardboard.


If it all pans out the way you say DV8, I might join you in that. If the objections to nuclear proliferation and waste are dealt with as easily as some on this list imagine, I’m all for it. (IF).

@ Peter Lang,
thanks for that. Let’s just say at this stage I’m very sympathetic to nuclear power.

One last exercise. I’m not saying the following is costed and competitive with today’s nuclear, but I’d question the synergies you suggest. Why 100% wind + gas backup? The papers coming out at the moment suggest that they build enough wind to be around 40% of the grid as baseload, and then the solar thermal operates with biogas backup.

The thermal turbines on the solar plant are already there. Just turn on the bio-gas taps and cook up the steam and the plant keeps operating. It prevents needing to build a whole new biogas plant & turbine, which would otherwise be necessary in the 100% wind + biogas system you have suggested above. (If the biogas actually comes from biochar it’s a carbon Negative system as well). Sure after the growing season’s you’d probably have to brew up one heck of a lot of biogas for storage, but that storage would probably not have to make 100% of the storage we use.

Don’t forget the V2G cars are coming that can charge whenever the wind is blowing, and then sell back when the grid demands it. If we use Better Place battery swap systems, the price is gratis of Better Place… they have included the batteries in the price / km of their public charging points and battery swap charges (which are already almost half the price of oil).

As my car sticker says, “My next car will run on the wind”. (Free Better Place propaganda sticker… if you want them to go nuclear, have a chat with Shai Agassi and I’ll put one of those on my car instead. My focus is Better Place and Australian independence on oil. I like the wind idea, but not if it really is distracting from the debate we NEED to have on nuclear).

Lastly, some are saying wind is cheaper than coal, IF we don’t have to cost a backup system.

Say we have a baseload nuclear capacity with wind power mainly charging our cars. Could that be economically competitive?



This is going on and on and on and you simply are not getting any of it. Can I beg you to have a go at answering your own questions. Just do a bit of thinking, and perhaps a bit of research for yourself.


If each house becomes a generator of solar and wind power there are minimal transmission costs!
Just a completely unrealistic use of resources.
Where’s the warp drive? OR FUSION REACTORS – NOT Fission?


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