Emissions Policy Renewables

CO2 avoidance cost with wind energy in Australia and carbon price implications

The following post is intended as a working paper for discussion. (It builds on work started by Peter Lang back in 2009, Does wind power reduce carbon emissions?) This current work is based on the methods and conclusions from the recently published work by Herbert Inhaber in the peer-reviewed journal Renewable and Sustainable Energy Reviews, entitled: “Why wind power does not deliver the expected emissions reductions“, and is applied to the Australian situation as a case study.

Clearly, there are large uncertainties on the Inhaber equation and they are not quantified. Discussion will almost certainly take place in the scientific literature about the Inhaber equation over the next few months to years. Inhaber, does point out that the chart is schematic, we do not have the emissions data needed and the many major uncertainties.

Peter and I look forward to your feedback. This is an important technical matter to resolve, with potentially strong implications for energy policy.

I note that there may be circumstances where some or most of these problems can be overcome, where the grid is ‘evolved’ or set up in a specially configured manner (unknown cost) — the below findings are most applicable to existing grids which are having wind added incrementally (i.e. all current [real-world] jurisdictions).

A 7-page printable PDF version of this paper can be downloaded here.

Addendum: Peter Lang’s Response to the American Wind Energy Association’s reply


CO2 avoidance cost with wind energy in Australia and carbon price implications

Guest Post by Peter LangPeter 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 presents a simple analysis to estimate the amount of CO2 emissions avoided by wind generation and the cost per tonne avoided as wind penetration increases from 0% to 20%. The carbon price implications are discussed. The analysis is based on a paper by Herbert Inhaber (2011)1. The analysis is for Australia’s National Electricity Market.

Emissions Avoided by wind generation

Herbert Inhaber (2011) reviewed eleven studies of CO2 savings by wind generation and concludes wind generation becomes less effective at reducing CO2 emissions as wind penetration increases. That is, wind generation avoids less CO2 as wind energy’s share of total generation increases. Inhaber explains:

as wind penetration increases, the CO2 reduction will gradually decrease due to cycling of the fossil fuel plants that make up the balance of the grid.

Below is an extract from the “Conclusions” and “Uncertainties” sections of Inhaber’s paper [in this extract, references to ‘Fig. 3’ are to the figure in Inhaber’s paper, which is reformatted and called ‘Figure 1’ here):

There are considerable uncertainties about how fast this decrease occurs, and the curve in Fig. 3 should be taken as only suggestive. However, the arc seems to be a mirror image of a sigmoid curve, with an equation:

where Q is the CO2 reduction in percent, x is the wind or intermittent renewable penetration of the grid in percent, and c is a constant, of the order of 0.2 in Fig. 3.

Figure 1: [Inhaber’s Fig. 3 reformatted to make it easier to interpret. In Inhaber’s paper, Fig. 3 is presented with log-scale on the vertical axis.]

Figure 1. (Inhaber Fig. 3.) A schematic graph of CO2 reductions as a function of wind (or other intermittent renewables) penetration into an electrical grid. Penetration is defined as the average fraction of energy contributed by wind to overall energy consumption...

5. Uncertainties There are considerable uncertainties in developing a curve of this type. A few of the many, not necessarily in order of importance, are:(a) The mix of fossil fuels used in the grid and the type of gas turbines in particular;

(b) Some of the literature on wind is of a polemic nature, either advocating its widespread use or pointing out its deficiencies. Care has to be taken to concentrate on the facts and leave opinions aside;

(c) Whether renewable energy is exported to other countries, as in the case of Denmark. This could skew results;

(d) The number of cycles of the fossil fuel sources that take place over time;

(e) What fraction of fossil fuel plants in the grid are relatively inefficient open-cycle gas turbines (as opposed to more efficient closed cycle gas turbines);

(f) The carbon dioxide intensity emitted from the fossil fuels used in the grid;

(g) The degree of variability of wind resources over a period of time, and a host of others.

(h) Funding sources for some literature is sometimes from proponents or opponents of the energy source;

(i) Some of the literature is not peer reviewed, posing potential problems in quality control.

For simplicity, let’s assume the average CO2 emissions intensity of Australia’s electricity generation is 1 tonne per MWh (The figure varies by state and by year ).2
From Inhaber’s chart, at 1% wind energy penetration, emissions are reduced by 90% per MWh of wind generation. This equates to a reduction of 0.9 tonne per MWh of wind energy. However, at 20% wind energy penetration the CO2 reduction is just 3.6%, or 0.036 tonne per MWh of wind energy.

CO2 Avoidance Cost

For wind power to be viable the price for electricity would need to be about $120/MWh. The current average wholesale price of electricity is about $30/MWh3. So wind energy must be subsidised by about $90/MWh. If we have a carbon price of $25/MWh then the Renewable Energy Certificates (RECs) need to reach $65/MWh to make wind viable. (That means the consumer must subsidise wind by $90/MWh, or three times the current wholesale price of electricity.). The figures are summarised in Table 1.

Let’s calculate the cost of emissions avoided by wind generation at 1% and 20% wind energy penetration.

From Inhaber’s chart, at 1% wind energy penetration, CO2 reduction is 90%. Using the emissions intensity for electricity of 1 t/MWh this equates to 0.9 tonnes per MWh. Wind energy costs $90/MWh more than the current average cost of electricity. This is the cost we must pay to avoid CO2 emissions with wind energy.

At 1% wind energy penetration, the cost per tonne CO2 avoided is:

$90/MWh / 0.9 t/MWh = $100/t CO2 avoided.

At 20% wind energy penetration the cost per tonne CO2 avoided is:

$90/MWh / 0.036 t/MWh = $2,500/t CO2 avoided.

These figures are for the cost to avoid an additional tonne of CO2 by increasing wind penetration.

Figure 2 shows the CO2 avoided and the cost of avoidance versus wind energy penetration.

Figure 2

Sensitivity Analysis

The CO2 avoidance cost is sensitive to the wholesale electricity price and to the minimum price needed for wind power to be a viable investment. Figure 3 shows the results for six scenarios. The inputs for the six scenarios are listed in Table 2:

Figure 3

The greatest uncertainty is the Inhaber equation. As Inhaber states “There are considerable uncertainties in developing a curve of this type.” However, to conduct meaningful sensitivity analyses on the range of possible values for the Inhaber equation is beyond the scope of this simple analysis. Inhaber’s paper does not include ranges for the constants in the equation.

Carbon Price Implications

A carbon price of $2,435 per tonne CO2 would be required for wind power to be viable at 20% penetration. This is for Scenario 1. The carbon price required for the six scenarios is plotted in Figure 4.

A carbon price of $2,435 per tonne is one hundred times the expected initial carbon price of about $25 per tonne CO2. This indicates how much the carbon price would need to increase to make wind power reach 20% penetration based on carbon price with an REC price about double what it is now. The Australian Renewable Energy Target is 20% renewables by 2020 and most of this is expected to be provided by wind power. The carbon price would have to increase by a factor of nearly one hundred above the likely initial carbon price to achieve the target.

For the carbon price to stay below $100/tonne CO2, wind energy penetration would have to be less than about 5% and the Renewable Energy Certificates price above $65 (for Scenario 1).

Another issue is that the carbon price will be paid by the back-up generator owners not the wind farm owners. This is clearly unreasonable since wind is contributing to reduced efficiency of the back-up plant.

Figure 4


As wind energy penetration increases from 1% to 20% the CO2 avoidance cost increases from $100 to $2,500 per tonne.

The quantities and costs calculated are sensitive to the input assumptions and input data but the broad conclusions are robust to the range of input values tested.

Considerable uncertainties apply to the inputs for the Inhaber equation upon which this analysis is based and therefore to the results. However, these uncertainties have not been quantified.

A carbon price of around $2,500 per tonne would be needed for wind power to reach 20% penetration. The Renewable Energy Target is 20% renewables by 2020 and most of this is expected to be provided by wind power. Therefore, the expected initial carbon price of about $25 per tonne would have to increase by a factor of one hundred to achieve the Renewable Energy Target.

For the carbon price to be below $100 per tonne wind energy penetration would have to be less than about 5% (and Renewable Energy Certificates price above $65 per tonne).

Wind energy is a high cost way to avoid CO2 emissions.

Australia is paying a high price for policies that mandate renewable energy while at the same time prohibiting other low emissions electricity generation options.


1. Herbert Inhaber (2011). Why wind power does not deliver the expected emissions reductions. Renewable and Sustainable Energy Reviews 15, 2557–2562

2. Department of Climate Change and Energy Efficiency (2010). National Greenhouse Account (NGA) Factors, Table 5.

3. Matt Chambers, “Force of the near future”, article in “The Renewable Energy Special Report”, The Australian, 16 May 2011; figures attributed to Tim Nielsen, head of economic policy at AGL.

4. ABARES (2011). Energy in Australia 2011. p22

5. EPRI (2010). Australian electricity generation technology costs, – Reference Case 2010. Table 10-9 to Table 10-11, p10-4


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.

368 replies on “CO2 avoidance cost with wind energy in Australia and carbon price implications”


Storage dramatically lowers the delivered cost of CSP because it more than doubles the plant capacity factor

Hmmm …. Possibly the capacity factor can be doubled through reducing the nominal output by one half.

Or the size of the mirror field can be doubled.

But there is no free lunch and no dramatic reduction in the LCOE.


David Benson, The LCOE you are quoting for solar thermal is not comparable with nuclear. It is for solar when the sun shines brightly in summer, not when needed. I suspect you know that already.


@ quokka and @ David B. Benson

In an Areva (CLFR) design, the solar field represents between 22-30% of the capital cost, with storage approximately 9-18% (7 to 14hrs).

Keeping it very simple; a sample plant of $2b would require field enlargement (let’s double it), so that’s another $600m, and 14 hrs storage let’s say $400m is $3b total. On our work, a CF for a sample plant just outside of Kalgoorlie would be around 72%.

With a 50% increase in costs, the $2b plant with a CF of around 20% has jumped to 70% or 3.5x the output.


Peter Lang, on 10 September 2011 at 12:26 PM — Actually its for solar thermal with about 7 hour thermal store. But of course it only achieves such a “low” LCOE is extremely sunny locations.

People living in/near such locations seem to want air conditioning in the daytime; funny about that.

But even so the cost would be much less using an NPP. Which was my prior conclusion.


David Benson, you didn’t give your source for your figure. If you are quoting EIA or DOE I suspect you have misunderstood what their figures are referring to. Could you please provide your source for your figures.


@ Thomas Stacy, If you haven’t already, I recommend you read chapter 5 in IEA Wind (2007) Task 25 Design and operation of power systems with large Amounts of wind power

Click to access W82.pdf

I realise that capacity credit for wind power is a controversial subject but this IEA report looks at a number of studies done in different countries.


@ David B. Benson

“(CSP) only achieves such a “low” LCOE is extremely sunny locations”

IMHO, that’s a strange thing to point out. A little like saying the way hydro “only” achieves it’s LCoE is in “wet” areas, or wind in “windy” areas perhaps?


@ Zvyozdochka

You make bold claims about a portfolio of CSP, wind, PV etc that will somehow solve the interemittency problem. This is absurd, as all of these sources are unproductive and non-dispatchable. If you run any numbers on this, based on real systems not some figment of imaginary systems like Greenpeace does in their ‘studies’, you will find that using a portfolio of CSP, wind, PV, still doesn’t get you to meeting the load. But what you will have done is add humongous variability and non-dispatchability in your system. So you just burn natural gas for the majority of your electricity supply.

The ‘portfolio approach’ is a dishonest politically correct intellectually insulting method of pushing more energy sources down our throat that are extremely marginal. We need a plan that adds up. Solar wind even combined don’t add up. They add up to natural gas grids.


Zvyozdochka, @ 9 September 2011 at 11:29 PM

You asked:

@ Cyril R and @ Peter Lang

What possible value is there in that Bill Hannahan thought bubble?

It provides perspective for those who do not appreciate the consequences of adopting non-hydro renewable energy. Some people realise that this is why non-hydro renewables provide negligible contribution to our power supply. Others can understand why renewables require huge subsidies and why they are delaying us adopting alternatives that can genuinely meet our present and future demand while improving energy security, power quality and reducing environmental damage.


@ Cyril R

“If you run any numbers on this ….. you just burn natural gas for the majority of your electricity supply.”

We have run the numbers and that’s not what we’re finding. We and our technical partners* have satisfied the investors who we’re contracted to and they’re progressing their proposals.

“The ‘portfolio approach’ is a dishonest politically correct intellectually insulting method”

No, it’s just the antithesis of ‘base load’, which appears to “offend” some, especially the coal and nuclear crowd.

* We’re not talking about Greenpeace.


@Michael Coggin (cross posted from

Do you have links OTHER than to AWEA press releases?
More importantly, I think you miss the one large factor that likely dominates, and that is fluctuation or the wind output (whether high or low) for that is what drives thermal plants into off-design operation. +/- 10% fluctuation is much more important if the wind is blowing at, say, 40mph than at 20. That effect of course is magnified with greater penetration. The plant specific heat rate curves used in EirGrid assume steady state (at various levels of opstate) not transient operation.


@Martin Nicolson:

The study would not download for me. Regardless, I use the terminology used in my grid region (PJM) and examine their justification for the CV of wind. But the real point is that since wind is negatively correlated to demand, it is ultimately “paired” with a set of generators acting inversely to the wind generation just to achieve a base-load performance standard. So wind should not rightly be considered a “stand alone” source of capacity to begin with.

Of course the pairing source is most efficiently and logically natural gas units, which, acting as base load sources WITHOUT ANY WIND MIRRORING are a far more cost effective means of reducing emissions associated with coal fired generation.


Peter Lang, on 10 September 2011 at 3:36 PM — A new solar thermal is just now under construction in the Mohave desert; maximum capacity factor is thus 25%. DoE provided a loan guarantee. From that and the other data about the build on Climate Progress some weeks ago it was easy to use the NREL simplified LCOE calculator to produce the quoted figure. That generally agrees with the cost, etc., data from Spain where such solar thermal units have been around for some time.


David Benson,

It hasn’t been built yet. It seems you are accepting a proponents claims. Surely you know better than to do this.

You quoted above LCOE of $230/MWh. I assumed you had got that from an authoritative source. It seems not. I asked you for the source. Still you have not provided an authoritative source so we can see what the LCOE is for. Therefore, I suggest you dismiss the LCOE figure you have calculated. You’d be better advised to use actual figures from operating plants – most of which run in for a few hours in the middle of the day, on a clear day in summer.


Peter Lang in response to Mike earlier: “Your assumption is not correct. I’d suggest you read the paper.”

The Inhaber paper does not address demand related thermal costs at all. As most grid/transmission system configurations exist now, even if you don’t have wind, you have thermal power plant penalties associated with following DEMAND.

A correct analysis of adding wind would be the quantum of (any) additional thermal penalty for required responses to SUPPLY. In other words, the operation of a real system with two varying components.

Inhaber makes no attempt at an examination or discussion of the demand based thermal penalties and then as contrast to adding supply based variance effects. Where is the description of the delta? (Actually, it was a waste of $19 for our research library).

The SASDO/AEMO 2011 report for South Australia describes emissions from generation fall with an increasing wind contribution and against rising demand (the operator directly attributes the fall to wind Based on this success, South Australia appears to be aiming for up to 35% wind contribution in the future.

There is also a claim (Windlab) that South Australian peaking plant have been used significantly less often (most recently repeated in Climate Spectator

Disclaimer: One of our clients operates Hallett (wind and OCGT/diesel) and they (not unsurprisingly) also disagree strongly with Inhaber.



Can I suggest you background yourself on the previous articles on BNC. They are listed on the Renewables Limits tab. There is no way I can cover all this history which I draw on in my responses.

Regarding your comments about the Inhaber paper, they reveal you clearly have not understood what it is about. But I sense there would be no point me getting into a discussion with you about it.

Lastly, since you are in the wind energy industry, can you provide any actual measurements of power station emissions? Do you have any actual measurements that demonstrate the emissions avoided by wind generation? (Hint: the answer is NO, because they do not exist!)


@ Peter Lang

“It provides perspective for those who do not appreciate the consequences”

I suggest it provides about as much information into the “problem” as my limit analysis on building all cars with solid gold steering columns.

This is actually a pretty good analogue to the situation: wind advocates suggest we add something that is expensive (gold steering wheel) and completely unnecessary onto existing systems (the car) while diverting attention from the real problem with the system (CO2 emissions from the fossil powered car). We should in stead be making plugin-hybrids, and not bother with the gold steering wheel.

Bill Hannahan’s paper is destructive to the cause of wind and solar enthusiasts because it reveals fundamental limitations to these energy sources. Namely, that they are incredibly marginal and this is related to their resource not the technology.


@ Peter Lang

“since you are in the wind energy industry, can you provide any actual measurements of power station emissions”

I am not in the wind industry.

Why don’t you have a crack at explaining the clear disconnect between your claims and the operator experience in South Australia? It would appear ~20% wind penetration has resulted in ~20% reduction in GHG emissions from generation (inclusive of demand growth) in the same period in South Australia, which the operator attributes to wind.

(The experience in Western Australia, where I am based at the moment, has been similar).
Please supply references for your figures.


I can only gasp at Michael Goggin of the AWEA and his comments about Ireland. Except for a few small gas engines Ireland doesn’t have any Combined Healt and Power plants used for domestic of commercial heating.

Furthermore, the work completed by Fred Udo and Joe Wheately is simply confirming the position of the Eirgrid engineers in 2004, who clearly pointed out the limitations involved with increased penetration of wind energy and how expensive it is when compared other forms of carbon reduction.

Click to access 2004%20wind%20impact%20report%20(for%20updated%202007%20report,%20see%20above).pdf

If anything the inefficiencies are worse than what those Eirgrid engineers predicted.

Furthermore it is the position of the Irish and EU authorities, despite the input from the engineering profession that 1 MW of wind energy displaces the emissions from 1 MW of thermal generation, this is clearly false. The dissemination of information on the environment to the public, which is not accurate, up to date and comparable (transparent) is a breach of the United Nations Economic Commission for Europe’s (UNECE) Aarhus Convention. The position of the EU and Irish authorities with relation to the renewable energy programme is the subject of a compliance investigation at UNECE, see the position of the Department in relation to emissions reductions from this wind programme:

Click to access frCommC54Annex_Reply_from_DCENR_5Sept2011.pdf

The meeting Agenda for the 21st in Geneva is also to be found at the bottom of the case’s webpage:


CHP comprises around 5% of Ireland’s generating fleet, and during cold spells like this when they are all running at full output that would be 10% or more of generation, which is large enough to drive the emissions increase noted, particularly if some of those plants are producing all heat and no power and therefore registering infinity emissions/MWh. As I pointed out, another major factor unrelated to CHP that explains the increase in per MWh emissions is that cold weather drives a sharp increase in electric heating demand, which causes less efficient, more expensive fossil plants to run as the higher demand forces grid operators to move up the supply curve of available generating plants. The EirGrid data clearly shows an increase in electric demand associated with the cold spells that are triggering the spikes in emissions/MWh.

Michael Goggin,
American Wind Energy Association


Michael Goggin, the issue here is not what CHP does to wind’s carbon savings, the issue is how do you power a country with energy sources that are not there most of the time, are highly sweeping swinging in their output, and cannot be turned on when necessary. If you do any sort of limit analysis to see whether this can be realistic you’ll find you just have to continue to burn lots of fossil with a little wind and solar. This is dangerous and dishonest greenwashing. We need a plan to cut emissions 90%. France did it for their electric sector, and we need plans also for non-electric fossil usage.


Emissions avoided by wind generation – Comparison of four researchers’s results

American Wind Energy Association (AWEA) argues that wind avoids about 100% of the emissions from the generators the wind energy displaces. Others argue as follows:

Kent Hawkins argues that wind avoids around 0%; and sometimes causes more emissions due to the effects of the cycling of fossil fuel back-up plants.

Herbert Inhaber’s equation (see Figure 1 in the lead article) says wind avoids about 4% at 20% wind energy penetration. Inhaber has lots of uncertainties and says his equation and figures are schematic. The key point of his paper is we do not have sufficient empirical data to know how much emissions are being avoided by wind generation.

Joe Wheatley and Fred Ido have been separately studying the Eirgrid data; they recently posted the results of their research:

Joe Wheatley states, in comment # 18:

I looked at CO2 savings per MWh of wind generation (relative to savings at zero wind penetration) as you suggested.

Here are the numbers:

Wind Penetration CO2 Savings

0% 100%
10% 90%
20% 77%
30% 62%
40% 47%

It is close to a linear decline.

Summary at 20% wind energy penetration those quoted above claim wind generation displaces x% of the emissions from the generators the wind energy displaces, where x =

AWEA = 100%
Wheatley (for EirGrid data) = 77%
Inhaber = 4%
Hawkins = 0%


Wow, so not 4%. I can sense the disappointment.

Given that South Australia intends to proceed to 33% wind penetration and they are competent managers who despite claims, know what they’re doing, perhaps the ~30% penetration ~62% savings will be significantly improved on by them too.



Can ypu produce any actual measurements of CO2 emissions from power statiosn that demonstrate how much emisisons is avoided by wind generation in SA?

Note, I ask for actual measurements, that is empirical data, not modelling studies.


So we have a range of emissions abatement from wind, according to studies, somewhere between 0 % and 100 %?

I wonder why the general public has absolutely no idea about where our energy future is headed, and who to believe?


What follows is an account of Wednesday’s United Nations Economic Commission for Europe’s (UNECE) Aarhus Convention Compliance Committee meeting in Geneva. The EU has ratified this International Treaty, which applies to Human and Environmental Rights, providing the citizen with access to information, public participation in decision-making and access to justice in Environmental Matters. The case concerned (Communication) relates to alledged failures of the EU to ensure compliance with its responsibilities under the Convention in relation to the renewable energy programme in Ireland:,16,Strategic Environmental Assessment – EU Position

The technical details are:

A highly interesting and demanding day at the United Nations building here in Geneva with regard to the Communication (compliance investigation) opened in my name against the EU (ACCC/C/2010/54). To reiterate, the Aarhus Convention itself, which links Human and Environmental Rights, is best explained by the three minute video clip on the United Nations Economic Commission for Europe’s (UNECE) website: . The Compliance Committee are distinguished specialists in environmental law from the greater European Area: . They meet about three to four times a year for about four days in Geneva, in order to hear a number of ‘test cases’ from the public and Environmental NGOs (Non-Governmental Organisations) in relation to a Party’s compliance. If the Communication is deemed to be of substance and the Party has not demonstrated adherence to the obligations in the Convention, then they will issue recommendations with a time frame with regard to the compliance. For instance in November 2010 it was concluded that the cost of legal access in the UK to challenge decisions in relation to environmental issues, such as planning cases (Belfast City Airport – cost £37,000), was too high and the UK is now having to undergo legal reform to lower the cost of taking a action in the Courts, which have to be fair, equitable, timely and not prohibitively expensive.

The situation in Ireland is both complex and shameful. Ireland will not ratify the Convention, as it is resistant to transparency in Governance and the provisions of the necessary Rights to its citizens, in particular with regard to access to the Courts. So essentially we are alone in Europe in this regard along with Russia. However, the EU ratified the Convention in 2005 and in theory it applies to Community Legislation in Ireland. UNECE cannot open a compliance investigation against Ireland, as we haven’t ratified. However, I was able to circumvent this limitation by taking the case against the EU in relation to the manner in which they had approved the State Aid for renewable energy, which led to the construction of most of the wind farms now in Ireland and €110 million in funding for the electrical interconnector going to Wales, both despite the fact that Ireland had shown a general disregard to the provisions of the Convention in matters related to renewable energy.

The outcome of the meeting, which followed on from previous consideration of an extensive set of documentation, see below, was that the Compliance Committee did not challenge the fact that there were extensive non-compliances by the Irish Administration in relation to (i) informing its citizens of environmental matters (Articles 4 and 5), allowing effective participation by Irish citizens in the planning process (Article 6) and policy development (Article 7) and the provisions of effective access to justice (Article 9) in a legal system, which is fair, equitable, timely and not prohibitively expensive.

What is clearly at issue now, and this is an inference from today as the outcome of the Communication will be most likely be agreed upon at their December meeting and finalised at their March meeting, is the following two main points:

(i) Did the EU fulfill its responsibilities to monitor the Convention in Ireland and ensure its enforcement (Article 3)? The Committee were clearly unhappy with what was presented by the legal team from the EU Commission. Hence they have given them two weeks to write back and confirm how they function to fulfill these responsibilities.

(ii) Under the 2009 Directive on renewable energy, we now have a programme in place in Ireland with a capital expenditure alone of some €30 billion, but with no environmental documentation in relation to what greenhouse gases it will save, what the actual cost will be, what the impacts are (landscape, population, health, nature), what alternatives were considered, what jobs will be created (or lost). While the Department of Communications, Energy and Natural Resources went out and collected a number of submissions from the public (mostly State bodies), the general Irish public were completely unaware of the scale, importance, costs, etc of this programme and did not participate in the decision making. Was this a breach of the requirement to provide the necessary information to the general public and ensure their active participation in the decision making and therefore a failure of the EU? The Committee discussed this National Renewable Energy Action Plan in depth and obviously will rule on it.


Pat Swords,

Thank you for that update. Very interesting. What you are doing will have ramifications ‘down under’, eventually. This bit gives some insight into its relevance for Australia getting better policy on clean energy

(ii) Under the 2009 Directive on renewable energy, we now have a programme in place in Ireland with a capital expenditure alone of some €30 billion, but with no environmental documentation in relation to what greenhouse gases it will save, what the actual cost will be, what the impacts are (landscape, population, health, nature), what alternatives were considered, what jobs will be created (or lost).

Readers wanting some more background:

There are more comments by Pat Swords on this thread.


I received an email from Pat Swords last night that is worth sharing. It was in response to an email to him in which I said:

The whole issue is very divisive here at the moment. The government has submitted the CO2 tax bills to parliament. It comprises 1100 pages and we had one week to provide a submission to the “Joint Select Committee on Australia’s Clean Energy Future Legislation”

I attach my submission (and addendum) for your information.

You can see my submission here: The addendum is the following comment.

Pat replied:

That’s crazy and also illegal. The UNECE Aarhus Convention evolved from Principle 10 of the Rio Declaration:
• Principle 10 “Environmental issues are best handled with participation of all concerned citizens, at the relevant level. At the national level, each individual shall have appropriate access to information concerning the environment that is held by public authorities, including information on hazardous materials and activities in their communities, and the opportunity to participate in decision-making processes. States shall facilitate and encourage public awareness and participation by making information widely available. Effective access to judicial and administrative proceedings, including redress and remedy, shall be provided”.
A complex 1,100 page document and only 1 week for the public to make Submissions!! This is clearly a complete mockey of Principle 10 and the how decisions should be made with concerned citizens at the relevant level through effective public participation. Furthermore, how is due account of your and other Submissions going to be taken in the final decision on this Bill?? Note: Australia clearly was a signatory to this Declaration and has actively promoted it (when it suited):

It’s not the technical content of what you are writing that is an issue anymore, but the fundamentals above. So you need to do two things, kick up a fuss in the media about the above (it is real easy to understand and will appeal to the Aussie mentality) and also find a good environmental lawyer. Basically, just because it is Green ideology does not give them the right to bypass the principles of democracy and environmental law.



While it is obviously up to Australia to implement its own administrative and legal structures, I am intrigued by the public participation exercise that Peter has referred to me.

I would recommend that interested parties check out page 121 of 198 of the below:

Click to access acig.pdf

It takes a considerable amount of time to prepare a Submission to such a complex document. So what are they going to do with it? Shred it if it doesn’t refect their position on the issue?

My advice and reflecting the information duties in Principle 10 of the Rio Declaration, would be to formally request the procedures which will be applied to the ‘taking due account’ of this public participation process, which clearly is of major significance in the future direction of Australia.


From Pat Swords, Pat Swords BE CEng FIChemE CEnv MIEMA

The 1992 United Nations’ Rio Declaration on Environment and Development is clear in Principle 10 that:
• Environmental issues are best handled with participation of all concerned citizens, at the relevant level. At the national level, each individual shall have appropriate access to information concerning the environment that is held by public authorities, including information on hazardous materials and activities in their communities, and the opportunity to participate in decision-making processes. States shall facilitate and encourage public awareness and participation by making information widely available. Effective access to judicial and administrative proceedings, including redress and remedy, shall be provided.
The EU’s renewable energy programme is completely by-passing these principles. Its implementation is therefore illegal, until such time as the public have been properly informed and allowed to actively participate in the decision-making at the relevant level. If the public, once properly informed, agree to the expenditure, massive impacts and little or no actual benefits associated with the current renewable energy programmes being implemented at a very rapid pace, then and only then can this programme be considered as legally compliant.

In the greater European and Central Asia area, Principle 10 of the Rio Declaration is formalised and expanded into the United Nations Economic Commission for Europe’s (UNECE) Aarhus Convention on Access to Information, Public Participation in Decision-Making and Access to Justice in Environmental Matters (see the second Attachment for more details).

The UNECE Aarhus Convention is currently completing an investigation into the implementation of the renewable energy programme in Ireland, where there have been systematic failures to comply with the Convention, which is implemented through a significant number of EU Directives.

However, the overwhelming evidence is that the same failures with regard to by-passing binding democratic procedures has occurred in all the other Member States, as the EU has rushed through this programme without providing sufficient timeframe for the necessary information to be prepared and the public to be properly informed. This therefore has by-passed democratic accountability.

The implementation of the EU’s 20% mandatory renewable target for 2020 occurs through Directive 2009/28/EC (attached).

• This Directive was passed in late April 2009.

• Under Article 4 (page 28) the EU prepared in late June 2009 a template for a National Renewable Energy Action Plan (NREAP), which Member States had to finalise and submit to the EU Commission by June 2010.
• These are now in place and used for the development of individual projects, such as wind farms.

• Wind farms are at a project level subject to Environmental Impact Assessment as they have significant environmental impact(Annex II of Directive 85/337/ECC as amended).

• A plan, programme, policy in the field of energy, which has significant environmental effects and leads to development consent is subject to Strategic Environmental Assessment (see Article 3 (2) (a) of Directive 2001/42/EC) (page 3 of attached).

• By only providing a year for the Member States to prepare their National Renewable Energy Action Plans, which are now in place and being used for individual projects, the Member States were completely unable to prepare the proper Strategic Environment Assessments, which comprise a detailed Environmental Report and comprehensive public participation (Annex I and Articles 4 and 5 of Directive 2001/42/EC). The timeframe was simply far too short for this to be done in a proper manner. Furthermore, the evidence clearly suggests this step was by-passed, as nineteen of the Member States simply left Section 5.3 of the template for the National Renewable Energy Action Plan completely blank. This was the only section of the template which addressed impacts and included a table of what greenhouse gas reductions were to be achieved, what the costs would be and what jobs would be created. This section was the only section of the template which was optional.

The situation in Ireland is that a Strategic Environmental Assessment has never been completed for the renewable energy programme. Indeed the public has never been informed of the objectives (e.g. tonnes of greenhouse gas savings), the impacts, the costs, the alternatives, including the do nothing and the resulting state of the environment, etc. Instead an enormous bill of billion of Euros with massive impacts on their environment will have to be paid for.

This is one of the key aspects of the current Aarhus Convention Compliance Committee Communication ACCC/C/2010/54:


Pat Swords BE CEng FIChemE CEnv MIEMA



Thank you for your response.
I had previously contacted EirGrid. They explained to me how they
calculate the CO2 intensity, g/kWh, every 1/4-hour for the entire grid.

They measure/record/log the output of each plant connected to the grid
every 1/4 hour, including the 11 CHP plants that sell to the grid. They have
the performance curves of each plant; Heat rate, Btu/kWh,
versus Output, %
They take the heat rate at the percent output and the calorific value
of the fuel to calculate the CO2 emissions, gram, for each 1/4-hour,
for each plant.
They divide the total CO2 emissions, gram, of all plants by the total
output of all plants, kWh, to obtain the CO2 intensity, g/kWh, for each
1/4-hour, for the entire grid.

None of the above is theoretical; it is a simple calculation. Most grid
operators measure/record/log such data sets, only Eirgrid and the
Colorado and Texas grid operators publish them.

The SEAI may have its own method of calculating CO2 emissions (a method
not explained anywhere with sample calculations, to my knowledge) which
may not be as simple as of EirGrid.
SEAI is likely addressing a less technical, more renewables oriented
I am always suspicious when folks present me with results without
showing me the detailed calculations.

Please note, EirGrid does not take into account the heat rate
degradation due to rapid up/down ramping to accommodate wind energy

This means the 1/4-hour CO2 intensities are understated by about 3 to 4
I have contacted EirGrid regarding this issue and they will get back to
I agree with you they are most helpful.

The Dr. Fred Udo study is based on the Eirgrid 1/4-hour data sets.

The results of his analyses shows the following:

During April 2011, 12% wind energy reduces the grid’s CO2 intensity,
gram CO2/kWh, by 4%.
During April 1st and 2nd, 28% reduces it by 1%.
During April 3rd and 4th, 34% reduces it by 6%.
During April 4th, 5th and 6th, 30% reduces it by 3%.

The above reductions are not anywhere near to what is claimed by the
wind energy proponents.

Below is the URL of the Dr. Fred Udo report.

Note: Paste this URL in the left field of your browser window to access
the site.

See below section from this article which was peer reviewed.


The gas turbines of the balancing facility, most efficient near rated
output, would have to operate at a less efficient, more polluting,
reduced output to be able to immediately vary their outputs to
accommodate all variations of wind energy, including unpredictable,
sudden, large variations of wind energy.

Gas turbine heat rates, Btu/kWh, and CO2 emissions, lb of CO2/kWh,
increase because of increased inefficient operation below rated output
of OCGTs, and CCGTs operating as OCGTs. For example: at 80, 50 and 20
percent of rated output, the heat rates are equal to the rated heat
rate divided by 0.95, 0.85 and 0.55, respectively, or a heat rate
degradation of (1/0.95 – 1) x 100 = 5.3%, 17.6%, and 81.8%
respectively; CCGTs are rarely operated below 40% of rated output,
because of much degraded heat rates. This is for steady operation at a
percentage of rated output. If the balancing facility is operating at a
percentage of rated output AND irregularly and rapidly ramping up and
down, the heat rate degradation increases further.

If a CCGT cycles from 100% down to 80% and back up to 100%; 1/2 hour
down, 1/2 hour up, its round trip fuel consumption and CO2 emissions
are 0.8 – 1.2 percent greater than if it had operated at 100% for the
same hour. The average output was 90%.

If a CCGT cycles from 60% down to 40% and back up to 60%; 1/2 hour
down, 1/2 hour up, its round trip fuel consumption and CO2 emissions
are about 20% greater than if it had operated at 100% for the same
hour. The average output was 50% which would have a steady heat rate
degradation of about 17.6%, plus a rapid ramping degradation of, say 3
– 4%, for a total of about 20.6 – 21.6 percent.

Click to access E02-gas_fired_power-GS-AD-gct.pdf

For example: a car driven on a level road at a steady speed of 40 mph
has a mileage of, say 26 mpg. The same car driven on a level road at
irregular and rapidly changing speeds that average 40 mph has a mileage
of, say 22 mpg. The mileage degradation due to the speed changes would
be (26-22)/26 x 100% = 15%. A car’s best mileage usually is at 55 mph,
at a steady speed, on a smooth and level road; it is the oft-quoted EPA
highway mileage.



This is the ‘All Ireland Wind and Fuel Mix Report’ (one table, three charts, no text) for November 2011.

The chart at the bottom of the page shows proportions of generation by fuel type at 15 minute intervals. It also shows what a system with a lot of wind generation looks like (21.7% wind energy penetration and 45.6% Capacity Factor for November).

Note that the hydro runs fairly consistently throughout the year (as I expect it would have to do in Australia too.) This demonstrates the point that the hydro cannot be diverted from its design purpose to try to make RE seem more viable than it is. Like Australia, their hydro component is small but very valuable.

They also have a small amount of CHP. But, unlike Australia, they have a wet country to grow the fuel per land area (and higher population density produces more waste per land area). That means their biomas and biogas fuels costs would be less than in Australia.


Two papers have just been released regarding the CO2 emissions avoided by wind generation and the economic effects of regulations forcing investment in wind generation:

Electricity in The Netherlands.
Wind turbines increase fossil fuel consumption & CO2 emission.

by C. le Pair


First we describe the models presently used by others to calculate fuel saving and reduction of CO2 emission through wind developments. These models are incomplete. Neglected factors diminish the calculated savings.

Using wind data from a normal windy day in the Netherlands it will be shown that wind developments of various sizes cause extra fuel consumption instead of fuel saving, when compared to electricity production with modern high-efficiency gas turbines only. We demonstrate that such losses occur.
Factors taken into account are: low thermal efficiency at low power; cycling of back up generators; energy needed to build and to install wind turbines; energy needed for cabling and net adaptation; increase of fuel consumption through partial replacement of efficient generators by low-efficiency, fast reacting OCGTs.

The second paper is:

Electricity Costs: The folly of wind-power
by Ruth Lea

Some extracts from the “Executive summary” state:

• Britain’s energy policies are heavily influenced by the Climate Change Act (2008) and the EU’s Renewables Directive (2009). Under the Climate Change Act Greenhouse Gas (GHG) emissions are to be cut by 34% by 2018-22 and by 80% by 2050 compared with the 1990 level. These are draconian cuts. Under the Renewables Directive Britain is committed to sourcing 15% of final energy consumption from renewables by 2020.

• These commitments add to energy costs and undermine business competitiveness.

• Nuclear power and gas-fired CCGT are …e the preferred technologies for generating reliable and affordable electricity. There is no economic case for wind-power.

• Wind-power is also an inefficient way of cutting CO2 emissions …

• Wind-power is therefore expensive (chapter 2) and ineffective in cutting CO2 emissions (chapter 3). If it were not for the renewables targets set by the Renewables Directive, wind-power would not even be entertained as a cost-effective way of generating electricity and/or cutting emissions. The renewables targets should be renegotiated with the EU.

Click to access electricitycosts2012.pdf

I am not vouching for these, just pasting the links for those who may be interested.


Wind Energy Does Little to Reduce CO2 Emissions
reviews Colorado, Texas and Irish experience. Links to appropriate studies are offered (the BENTEK study has been subject to criticism regarding methods employed — not mentioned in the linked article.)
There are some aspects of gas turbines which the article author appears misinformed.

Despite this (and not caring for the conclusion, the article provides a fairly decent summary of some of the experience with wind turbines.


Thank you Martin Nicholson for this link (posted on another thread).

This paragraph from the Executive Summary reinforces an important message:

An analysis of the effect of an increasing wind market share on residual demand shows that wind significantly alters the load duration curve (LDC) of residual demand, changing not only its size but also its slope. Comparing the LDC of demand and residual demand shows how wind strongly decreases the average capacity factor of residual demand; the share of capacity running at high capacity factors (70% to 100%) decreases, while the amount of capacity running at low capacity factors (0% to 30%) increases strongly. A decreasing capacity factor can have a significant impact on the relative profitability of investments in different types of generation capacity. As the capacity factor decreases, the levelised costs of electricity (LCOE) of generation technologies with high investment costs, such as coal‐ and especially nuclear‐fired capacity, increase faster than those of technologies with lower investment costs, such as gas‐fired capacity.

So wind generation increases the cost of electricity by more than just the higher cost of the wind energy itself. It also increase the cost of electricity from the whole system because it forces the cost of electricity from the baseload generators to be increased (because their capacity factors are reduced).


More on the hidden costs of wind power:

Even though the effects of an increasing wind market share on gas markets are relatively limited and there are several tools available within natural gas systems that can support an increased demand spread and unpredictability, natural gas should not be seen as a inexpensive or easy way to support a higher wind market share. An increasing wind market share strongly decreases the capacity factor of gas‐fired generation capacity, thereby increasing the levelised costs of electricity (LCOE) of electricity production by gas fired generation technologies. The diminished capacity factor also leads to a decreased utilisation rate of transport capacity bringing gas to gasfired generation plants, leading to higher transport costs.

Finally, the additional flexibility required to cover the higher demand spread is likely to be needed only a very small fraction of the time, making instruments such as natural gas storage or LNG regasification capacity relatively expensive sources of flexibility.

Click to access impact_of_wind_power.pdf


Martin Nicholson wrote:

Thanks Peter. It will be interesting to see what our colleague at AWEA thinks of this. He seems to enjoy quoting the IEA when it suits him.

Peter Lang wrote:

More on the hidden costs of wind power:

According to the study, there appears to be relatively little impact on energy utilization or ramping rates as a consequence of wind: “As there is no significant correlation between wind output and electricity demand, and increasing wind market share neither amplifies nor dampens existing power demand patterns and does not strongly increase demand variability or the size of demand changes” (page 7).

Rather, the more significant concern is the impact on fixed costs on supplemental generation as a result of lower capacity factors. And as the study shows, these impacts are larger for nuclear and coal (which have larger fixed costs) than natural gas plants (which have lower fixed costs). LCOE impacts are thus seen to be much smaller in the case of natural gas plants providing backup, regulatory and balancing services. The main conclusion of the study is summarized on page 31: “Because of lower investment costs for gas‐fired units, their production costs do not increase as rapidly as those of coal or nuclear power when the capacity factor drops. The relatively low investment costs make natural gas an economically attractive fuel for delivering flexibility to the system, running at a relatively low capacity factor.”

The study also suggests other tools for better managing energy utilization from wind, and thus spreading out the impacts on fixed costs of other generators providing flexibility to the system: “energy storage, demand‐side response, increasing electricity interconnection capacity and trade, and supply‐side response” (page 23). These costs do not appear to be hidden as you suggest, but appear to be detailed in a revealing way in the study? In fact, other studies (such as your own cost estimate for EDM model), looks at these system wide impacts and factors them into their total combined cost or price projections.


I suggest your first paragraph missed the meaning in what you quote. The output from industrial wind turbines doesn’t have any relation to demand.

The ‘residual’ demand is greater, and changes more abruptly, the more wind there is – so flexibility in other sources is necessary to provide the ‘residual’ supply. Looking at the reports comments on ramping, they seem to be somewhat dismissive because in the data set they are observing, the change in wind over a short period of time was not greater than they observed in the change in demand. If they’d looked at Texas data from August, they’d see the typical day has demand increasing as wind output decreases, and would see the error of their assumptions pretty quickly.

There was recently a study/survey of system operators that collected their perceived requirements for integrated large-scale renewables. The desired tools for integrated more wind?
More accurate wind forecasting as #1
More Flexible conventional generation as #2

Pg 10 at


Scott Luft wrote:

If they’d looked at Texas data from August, they’d see the typical day has demand increasing as wind output decreases, and would see the error of their assumptions pretty quickly.

Yes, the study does note this, and says that results will differ depending on country/site specific wind output and electricity demand patterns. Do you think this also holds true for Texas wind farms located along the Gulf Coast? Presumably, this is why we want wind plants dispersed (and not concentrated in a single location). They suggest these impacts are “relatively limited” (page 8), and suggest available tools for handling issue so as not to become problematic: improving wind forecasting models, increasing natural gas storage capacity, access to LNG sources, and more flexible import contracts.


The Texas wind generators on the coast peak in the afternoon with on shore breezes in the afternoon that is coincident with the system peak demand, whereas the West Texas wind seems to peak during off peak periods and seasons. There is a study that is trying to determine the effective load carrying capacity at each location. Maybe we will have results soon from that study.


I don’t think the discovery of exceptions, in trends, disproves the general findings, here and elsewhere, that it is not always windy somewhere. The more intermittent supply added, the lower the capacity factor of all the other sources is a premise that is likely to be true. The less frequently very low output from renewables happens, the lower the capacity factor of other sources.
Gene would have a much better idea of Texas, but my understanding is they have large cost overruns to expand the transmission capacity to allow more West Texas wind – the source that doesn’t have the coastal peaking pattern in matching annual peak hours.
It’s hard to tell how big the technical issues are as the economic tools hugely distort the picture.
In the US it is an industry driven by the credit on total MWh; attempting to match demand profile ins’t relevant. The situation is worse with solar, as CSP projects were dropped a number of times in the past 12 months due to dropping prices of PV, which I see as annual MWh being valued over the ability to provide scheduled output.
Technically and/or due to the nature of subsidies, capacity factors are dropped across the rest of the generator portfolio.


The West Texas wind is given a capacity value of 8.7% last time I checked. Some studies indicate it could be a bit higher but ERCOT elected not to raise it. I suspect that when the higher capacity value was determined they may have included the coastal wind in that determination since that was a much smaller amout of coastal wind than West Texas, something like 9 GW West Texas and about 2 GW coastal, but those values are increasing. The original 5 G$ transmission cost for West Texas wind is now over 7 G$. The intent was to invest in transmission to achieve 18 GW of wind. The rumor mill has it that there is a Texas 35 GW wind study underway. The coastal wind roughly coincides with the demand. The West Texas wind mostly cuts into gas and coal generation. The anti coal folks think that this will help Texas be able to shut down its coal plants. They aren’t taking the capacity needs into account that coal supplies. I was listening in on an ERCOT conversation today about setting up the future load flow cases and there was a question that was asked by a member that reveals our dire situation here. He asked, what are we going to do if we dont have enough generation in the model to meet the peak demand that is being forecasted? I don’t recall there was a good answer to that question. I suppose they could just increase the wind capacity in the model to meet the peak demand plus losses. That would create the load flow case, but what if the wind is not blowing hard enough at that time to generate that much power? This is where the need for backup generation is apparent. Even if we assign a certain effective load carrying capacity to wind on the coast and in West Texas, there is always a good chance the wind will be much less than what is needed. The only recourse is to have load reduction. And there are many different ways ERCOT is trying to do just that. Its going to be an interesting summer.


Scott Luft,

If they’d looked at Texas data from August, they’d see the typical day has demand increasing as wind output decreases, and would see the error of their assumptions pretty quickly.

That is commonly the case in Australia too. Look at the monthly charts or download the data from this site


If wind is treated as ‘must take’ then it ought to be treated as negative load. The net load for the schedulable generators is then

Net = Actual – Wind

and this can easily create ramping difficulties for those generators which change power relatively slowly. But even hydro, fastest in ramping, suffers additional wear and tear due to the increase in the frequency of fast ramping.


@DBB, your invoking a negative to an unwanted input is most elegant.

In a price-driven scheme, applying a negative price to an unwanted input would motivate an oversupplying producer to divert his power elsewhere than the grid.


Roger Clifton — It is not price but the power requirements for electricity where total generation must always equal total demand. I’ve just followed Anjan Bose’s thought to treat wind power as neagtive load. The elegance is his.


Leave a Reply (Markdown is enabled)

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s