Lacklustre results from the Colorado Integrated Solar Project

A common lament of those analysts wishing to get to grips with the real-world performance of solar thermal power plants has been, well… an absence of data. Trainer noted, in ‘Solar Thermal Questions‘:

It would be great to get some actual data on their year round performance. I have found it fiendishly difficult to get such data out of anyone; they seem not to want to make it public, and this makes evaluation of claims very difficult.

During the Equinox Energy 2030 summit, Jay Apt noted some issues with utility-scale PV farm performance, as illustrated in the figure below (from this paper):

Note that this is from a solar PV farm in the Arizona desert — one of the best locations in the US for this type of facility. The associated commentary said:

Observed rapid and deep fluctuations at time scales of 10 seconds to several minutes may indicate that a component of the intermittency is due to low, scattered clouds with significant opacity. We observe a number of examples of output power rising above nameplate capacity before and after deep drops in power. This may be due to focusing of sunlight around the edges of low clouds. If PV becomes economically attractive enough to be deployed at large scale, intermittency is likely to be matched with dispatchable power, storage, and / or demand response

The implied ramp rates to compensate for these types of fluctuations will be challenging. Indeed, some form of large-scale battery energy storage seems vital to maintain quality of the electricity output.

That is PV. Now, at last, I have some data on solar thermal performance. It comes from the final report of the Colorado Integrated Solar Project, which you can download here (25-page PDF).

First though, some details on the facility:

The world’s first hybrid solar/coal power plant has been built near Palisade in Colorado. Xcel Energy and Abengoa Solar are partnering on the demonstration project which uses solar parabolic trough technology to supplement the use of coal. Initially, it’s expected to reduce the emissions generated by the Cameo Station’s Unit 2 plant by three to five percent, but it’s thought that this could increase to up to ten percent.

The system focuses solar energy on mineral oil, which is then passed through a heat exchanger where it’s used to preheat the water used by the coal-powered part of the 49MW plant.

You can also go to its National Renewable Energy Laboratory page for further technical specifications on the plant. In short, the expected generation was 49 MWh per year for the 6 acre parabolic trough facility, with a 2 MW turbine capacity. The NREL page says:

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The Argument For Nuclear Energy In Australia

This is a piece written by me (Barry Brook) and my Ph.D. student, Ben Heard, as part of the “Nuclear Debate” series on the New Matilda news/opinion site. The original article can be read here.

By now, most of you would have heard that the Premier of South Australia, Labor’s Jay Weatherill, has announced a Royal Commission into an expanded future role for the state in nuclear energy. For people like us, who are both strongly focused on tackling climate change by eliminating Australia’s dependence on fossil fuels, and who consider nuclear to be an essential tool, this is real progress.

In a recent article on The Conversation, we explained the types of issues we think the Royal Commission might consider. These obviously only represent our opinions and perspectives, albeit well-informed and researched.

We cover most of the well-trodden ground on radioactive waste management and energy generation. We also explain a number of reasons, ranging from political to economic to geological, why we think South Australia is a particularly good place to kick-start any deeper foray by our nation into the nuclear fuel cycle.

One thing that particularly frustrated us was the immediate condemnation of the news by the SA Greens Party, and disappointingly, also by the Australian Youth Climate Coalition.

The whole point of Royal Commissions is the rigorous uncovering of facts, based on solid research and deep consultation with experts, government and public representatives. So why the objection?

Well, the arguments are well rehearsed and endlessly debated. Nuclear is too costly, unsafe, produces dangerous and intractable waste, is connected with weapons proliferation, is unsustainable, and besides, is unneeded.

Such a ‘washing list’ of objections is superficially convincing, and the last one in particular appeals to most people’s sensibilities. Australia is large, sunny and sparsely populated country with long, windswept coastlines. Surely then, we can (and should) do it all with wind and solar, and forget about dirty and technically complex alternatives like nuclear fission?

The thing is, with an issue as serious and immediate as climate change, we can’t afford to be carried away by wishful thinking, nor get trapped into thinking that ‘hope’ is a plan. We owe it to the future to be ruthlessly pragmatic about solutions, and accept that trade-offs are inevitable.

So, in as brief a summary as we can put it, here is the state of play was we see it.

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Critique of the proposal for 100% renewable energy electricity supply in Australia

Below is a new, detailed critique by Dr Ted Trainer of the simulation studies by Elliston, Diesendorf and MacGill on how eastern Australia might be run off 100% renewable energy. The summary:

Three recent papers by Elliston, Diesdendorf and MacGill (2012, 2013a, 2013b) elaborate on a proposal whereby it is claimed that 100% of present Australian electricity demand could be provided by renewable energy. The following notes add considerations arising from the last two papers to those discussed in my initial assessment of the first paper. My general view is that it would be technically possible to meet total Australian electricity demand from renewables but this would be very costly and probably unaffordable, mainly due to the amount of redundant plant needed to cope with intermittency. This draft analysis attempts to show why the cost conclusions EDM arrive at are probably much too low.

Ted has also updated his critique of the Zero Carbon Australia’s report on 100% renewable energy by 2020. The original BNC post is here, and the updated PDF here.

Ted notes the following:

These efforts have taken a huge amount  of time and I am still not clear and confident about my take, mainly because neither party will cooperate or correspond.  Thus I have not been able to deal with any misunderstandings etc. I have made.  Both critiques are strengthened by information I have come across since circulating previous commentaries, but they are essentially elaborations on the general line of argument taken in earlier attempts.

I find this unwillingness to engage on these criticisms by the primary authors disappointing, but typical.


I think these three papers are valuable contributions to the considerable advance that has occurred in the discussion of the potential of renewables in the last few years. My understanding of the situation is much improved on what it was three or four years ago and I now think some of my earlier conclusions were unsatisfactory. EDM take the appropriate general approach, which is to look at how renewable technologies might be combined at each point in time to meet demand, or more accurately, to estimate how much capacity of each technology would be required, especially to get through the times when solar and wind input is minimal. EDM put forward a potentially effective way of coping with the problem of gaps in their availability via biomass derived gas for use in gas turbines. My earlier analyses did not consider this.

It is not difficult for an approach of this kind to show that electricity demand can be met, and many impressive 100% renewable energy proposals have been published. (For critical analyses of about a dozen of these see Trainer, 2014), but a great deal of redundant capacity would be needed, and the key questions are, how much, and what would it cost? My present uncertain impression is that Australia might be able to afford to do it, but if it could it would be with significant difficulty, i.e., with major impacts on lifestyles, national systems and priorities, and on society in general.

A major disappointment with the EDM analyses is that for some crucial elements no data, evidence or derivations are given and as a result the proposal can only be taken as a statement of claims. We need to be able to work through the derivations in proposals such as this to see if they are sound or what questionable assumptions might have been made etc. Consequently I have had to spend a lot of time trying to guestimate my way to an assessment of the cost conclusions and it is not possible to confident about the results.

Required capacity?

A merit of the EDM approach is to take as the target the present demand. This avoids the uncertainty introduced when attempting to estimate both future demand and the reduction in demand that conservation effort etc. might make.

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New critique of AEMO 100% renewable electricity for Australia report

Guest post by Dr Ted Trainer, University of NSW (

For other critiques of the “100 Per Cent Renewables Study – Draft Modelling Outcomes” report on BNC, see here and here.

Summary: The AEMO report concludes that 100% of Australian electricity demand could be met by renewable energy sources. The claim is far from established and highly challengeable because some of the assumptions etc. are implausible and not likely to be borne out, and some crucial factors haven’t been taken into account. Intermittency has not been dealt with at all satisfactorily, embodied energy costs seem not to have been considered, and it is admitted that some major costs have not been included. It is clear that a thorough study would have arrived at an annual capital cost in the early years of construction that was several times the sum claimed. The main issue with renewables is not whether it is technically possible for them to meet total demand – it is whether the large amount of redundant plant needed to deal with intermittency could be afforded.


This study concludes that 100% of Australian electricity demand could be met by renewable energy sources.   I think it is a valuable study, providing useful information, the kind of exploration we need, and in general its pronouncements are acceptable —  if the assumptions and inclusions/exclusions that are made clear are accepted.  However the 100% claim is far from established and highly challengeable because several of the assumptions etc. are implausible and not likely to be borne out, and some crucial factors haven’t been taken into account.  Intermittency has not be dealt with at all satisfactorily, embodied energy costs seem not to have been considered, and it is admitted that some major cost factors have not been included.   It is clear that a thorough study would have arrived at an annual capital cost in the early years of construction that was several times the sum claimed..  Following is a brief indication of some problems.

The amount of redundant, back-up plant required.

The core issue with high penetration renewables claims is to do with the amount of plant that would be needed to deal with the intermittency of wind and sun.  When both are low supply can be maintained only if there is a substantial amount of some other kind of generating capacity, or of storage capacity, that can be turned to.  Proposals attempting to provide for this end up having to assume very large quantities of back-up plant.  For instance in the Elliston, Diesendorf and MacGill proposal (2012) the multiple is 3.37.   In the Hart and Jacobson proposal for California (2011) the multiple is 4.3.  They found that in order to meet a 66 GW demand with low carbon emissions no less than 281 GW of capacity would be needed.  This would include 75 GW of gas generating capacity which would function a mere 2.6% of the time (p. 2283) and it would provide only 5% of annual demand.  This means 75 power stations would sit idle almost all the time.

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Critique of Lovins book ‘Reinventing Fire’

The following is a critique, by Ted Trainer, of the energy chapters in Amory Lovins’ new book, Reinventing Fire: Bold Business Solutions for the New Energy Era. Ted is seeking feedback, so please head over to the BNC Discussion forum and leave your comments — on his appraisal, or on your own thoughts of Lovins’ prose.


A note on the energy chapters in, A. Lovins, Reinventing Fire, Rocky Mountains Institute, 2011.

Ted Trainer, UNSW

This book continues the presentation of the Lovins perspective, essentially the claim that there is great scope for conservation measures and alternative technologies to solve our problems and enable maintenance of rich world economies and lifestyles.  He says at least 80% of US power, and possibly all of it can come from renewable energy sources by 2050.  My comments refer only to the two energy chapters, one on transport fuel and one on power supply.

I don’t think these chapters add much to his Winning the Oil End Game.  More importantly, I regard the arguments as quite unsatisfactory and unconvincing.  They are almost all superficial; there is no detail and no derivation of conclusions.  The core issues require numerical analyses; they are about whether or not quantities and targets can be achieved but there are few if any explanations of this kind in the energy chapters.  The approach is to make vague and generalised claims, support them with a few spectacular examples, and proceed as if this establishes that the practice in question could be implemented everywhere.  As Smil (undated) said long ago, Lovin’s style is “… discourse by declaration.” This is disappointing as Lovins has extensive expertise on these issues and it could have been applied here more effectively to clarifying the potential and limits of renewable energy.

Lovins claims huge reductions in energy demand will be achieved by efficiency effort.  His renewable scenario actually assumes a 70% reduction on the level of electricity demand he says that business as usual would produce by 2050 (from 6000TWh/y down to 1650 TWh/y.)  I can’t find any evidence or reasoning supporting this claim in the book. There is much discussion of energy reducing technologies, but no case that these would add to the claimed reduction.

Regarding the difference conservation etc. might make, the estimates I am aware of for the rich countries indicate in recent years a business as usual demand trend rising to about twice the present level by 2050. (Demand is down at present, partly due to the GFC.) Clear and confident estimates of future efficiency gains do not seem to exist, understandably, but for working purposes I assume a 33% reduction to the level business as usual would generate. Note that US population is rising significantly (.91% p.a.) and at this rate would be 50% higher by 2050, so Lovins is actually assuming a very big reduction in energy consumption per capita by 2050.

Smil is one among many who stress the huge gulf that typically exists between what is technically/theoretically possible on the laboratory bench and what is likely to be achieved in the real world.  In my critical discussion of the “Tech-fix” position (Trainer, 2012a) I set out the cascade through what might be a) “theoretically possible” without consideration of limiting factors, b) technically possible given real-world difficulties, c) economically possible, e.g., in view of the infinite cost of being as efficient as is possible, d) has an acceptable EROI, e) is socially acceptable, and f) is the final achievement after the Jevons or rebound effect has operated (e.g. where increased car efficiency results in an increase in driving and fuel use.)  A good example is where Smeets and Faaij (2007) conclude that global biomass production potential is 1,550 EJ/y, but Field, Lobell and Campbell (2007) conclude that the amount that might be obtained after taking into account all limiting factors would be a mere 27 EJ/y.  I don’t think there is any reference in Lovins’ two energy chapters to any of these factors, or even to the EROI concept.

Lovins always has an enthusiastically optimistic view of probable future trends in costs.  However discussion of all issues to do with energy, resources, technology, environment and consumption should be based on the assumption that in the near future there are very likely to be large and irreversible rises in the prices of energy, resources, materials, construction, plant and technology etc.  These will multiply through the whole economy, impacting further on the construction of new energy technologies, cutting into the availability of capital to build them in large quantity, and into the incomes and capital available to pay for energy and efficiency improvements.


It is not difficult to show how most or all energy could come from renewables; you just assume enough plant to do it when there is little sun or wind. My main interest is in the capital cost of the energy technologies required to enable demand to be met at all times, and my general view is that renewable energy will be much too capital costly to run consumer societies. (The best current statement of the case is Trainer, 2012b, and as applied to Australia, 2012c.)

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