Oz-energy-analysis.org Officially Online

Bravenewclimate today announced the official opening of oz-energy-analysis.org, an open science site. Introductory material in oz-energy state,

Our problem is to describe what would be involved in running Australia (in particular South Australia) predominantly on renewables.

In order to focus on this problem, we exclude others from consideration. While we have various views on climate change and nuclear power (to mention the two big ones), you will not find these laboured here. . . .The big problem with renewables, particularly wind and solar, is that 'the sun don't always shine and the wind don't always blow'. That is to say, these are variable sources of power, and we want to introduce them into a system that is currently "electricity on demand".

The variability of renewable power can be managed in various ways: (i) by having different renewable technologies in different places (so that if one source isn't making much electricity, others might be), (ii) storage (such as pumped hydro, thermal storage, and chemical conversions), (iii) demand management, and (iv) backup systems (gas turbines, probably).

But wait, I hear you cry, there are renewables such as geothermal and ocean currents that -are- regular. Which is (sort of) true, but are these technologies tested and ready to roll? And how much power can they produce?The next big problem is cost. While people might be prepared to pay a bit more for electricity (and for the things that use electricity in their production - which is just about everything), massive price hikes are unlikely to be acceptable to society at large. While we do not start with a full economic analysis, in all the work we do on this site we have these economic aspects in mind. Before policy makers can make decisions, before investors put money into infrastructure, options need to be costed.

I welcome the application of of a rational scientific approach to the problems of powering society with renewables, coupled with the use of an open and public internet forum in which transparancy is the order of the day.

Nuclear Green in a Nut Shell

I among others have been challenged for taking advocacy positions instead of offering analyses, and listening to people who disagree with my views. Yet I and others, for example Barry Brook, are simply advocating positions we arrived at by analysis after talking to people who hold different views. I came to the conclusion that I advocate by asking how a post carbon grid would operate. I assumed that everything was on the table, but what the climate scientists were telling us we needed to get rid of 80% of our CO2 emissions. I did a brief sector by sector analysis of the energy economy, and determined that the most obvious place to start was the generation of electricity for the grid, the sources of space heat, and hot water, and the replacement of fossil fuels in transportation. Since I was not sure about the elimination of fossil fuels in other sectors. i decided that it would not be wise to assume that the sectors I was ignoring were good candidates for an 80% fossil fuel reduction. This included agriculture, the military, and air and water born transportation.

I concluded that the electrification of rail transportation was practical, and that electrical rail had good potential to replace long range trucking. I further concluded that solar systems could provide hot water in many parts of the country, and that there was good potential to use solar for space heating in some areas. I also noted that in much of the country, air conditioning was the rule in homes, offices and businesses. Although ground source heat pumps are efficient, they are expensive and also expensive to service. Air source hear pumps rely on a technology that is very similar to air conditioning, Replacement cycles for air conditioning systems are such that most of the cost of air source space heating conversion would be covered by the cost of replacing worn out air conditioning systems.

I had some doubts about biofuel replacements for fossil fuels, but I came to the conclusion that batteries and capacitors technology was evolving rapidly enough to replace fossil fuels in non rail surface transportation by 2050. Thus electrification offered a significant part of the solution, and thus it was very important that the decarbinization of the grid would approach 100% by 2050.

I then looked at efficiency, of which much was expected. I quickly discovered that there was a serious conceptual problem with the efficiency solution. Economists have known for 150 years about Jevons Paradox. Jevons a 19th century resource economists, had discovered that greater efficiency in the use of coal lead to more demand for coal. Other economists have noted that if efficiency does not always lead to an increase in energy demand, a rebound effect is quite robust. And thus in the absence of energy price increases efficiency cannot be counted on for big carbon use savings.

I noted that some other people were advocating a simplified lifestyle. Most people, i thought, would prefer to not adopt such a lifestyle. I concluded that the simple lifestyle was likely to lead to greater social conflict, a diminished quality of life, and a lower life expectancy. Some people were pointing to Cuba as a model for a low energy simplified society, but i felt that such a choice came with the cost of political and human rights for the Cuban people, and that most of the people of Cuba would prefer a high energy lifestyle if they could choose. The evidence for this was obvious, Cuba was a dictatorship. The communist party of Cuba maintained control of political power, and was prepared to use violence against anyone who objected.

Thus I felt that there was no alternative to replacing CO2 emitting electrical generation capacity with post carbon electrical sources. I had not ruled out renewables, but I felt that intermittency was a problem to be solved. I looked at the problem of intermittency, and asked renewable advocates what they would do when sun and wind failed. Use the grid for backup they answered. But I asked, I thought we wanted to get rid of carbon sources on the Grid. After they discovered I was not going to accept the Grid answer, they offered efficiency. When i brought up Jevons and rebounds, they turned to backups like batteries, pump storage, and Compressed air storage. I investigated all of these proposed back up technologies and found that they were all expensive and were inefficient to boot. Compressed air storage, required the of natural gas. A further renewable strategy is to create redundant solar and wind facilities, and link them with an expanded grid. The linked system is more likely to provide reliable electricity, than stand alone solar or wind units. However like energy storage backups, the redundancy plan turns out to be more expensive than conventional nuclear power systems. I did offer one novel renewable back up plan. Molten Salt Liquid Fluoride Thorium Reactors can be built with low prices and have attractive features that makes them useful in peak power.back up roles. LFTRs thus could provide reliable, relatively low cost backups for renewables. But, the LFTRs would be capable of operating full time. Thus it would be cheaper to remove the renewable electrical sources from the system and simply operate the LFTRs full time.

When I calculated the cost of renewables with backup, and compared it to the cost of nuclear power I reached the conclusion that nuclear power was cheaper. Renewable advocates rejected this conclusion. Nuclear has to be more expensive, they said. They complained about how unsafe reactors are. They pointed to the so called "problem of nuclear waste." They raised the issue of nuclear proliferation. They argued that we were running out of uranium.

But i was aware of a Generation IV nuclear technology that could answer all these issues. it was Molten Salt technology, and i knew about it, because my father had worked on it for 20 years. So I reviewed the evidence accumulated in Oak Ridge between 1950 and 1980. i reviewed the ORNL research, and looked at recent discussions. There seemed to be a strong case. Another Generation IV technology, the Integral Fast Reactor appear to also offer viable solutions to many unclear power issues, but is likely to be more expensive and more technologically challenging than MSRs, and objections may be raised on grounds of nuclear proliferation dangers. Generation III and even Generation II nuclear technology appear to be an acceptable bridge, but conventional nuclear technology does not solve all the problems that MSRs and IFRs will solve.

All of my conclusions have come by analysis. I have listened to the advocates of other viewpoints. My analysis points to the following conclusions:

1. Fossil Fuel are on their way out as energy sources.

2. Fossil fuel energy technology will have to be replaced.

3. Efficiency cannot be counted on to replace fossil fuels use.

4. Renewables require back up.

5. Renewables with fossil fuel back up will not meet 2050 carbon emission goals.

6. Renewables with energy storage back ups will be more expensive than nuclear.

7. Renewables with redundancy will be more expensive than nuclear.

8. Nuclear power is a less expensive and more reliable source of post carbon electricity than renewables.

9. Generation IV nuclear technology offers many attractive features, and could solve some or all of the objections now raised to nuclear power.

Since I first completed this analysis, I have reviewed its components on a number of occasions. My reviews continue to demonstrate that my analysis remains sound. During the last 3 years numerous studies related to components of my analysis have been published. These studies point to the same conclusions. Further, these studies have not received effective contradiction. This is the case for my original analysis. There is a growing body of evidence that the renewables paradigm has failed.

My advocacy is primarily based on reports of the findings of my analyses and the analyses offered by others. I believe that those who disagree with us need to offer strong reasons for doing so, or loose credibility. So far they have not done so,

Obama Deserves an F on Energy Policy

The Obama administration is off to a truly disastrous start on its energy policy. It has accepted the delusion notion that supporting nuclear energy is somehow anti-progressive while giving preference to so called renewable energy sources is good policy.

Here are Obama's energy delusions. Mr. Obama appears to believe that the problems of conventional nuclear power are crippling compared to renewables. That is not the case. In facts renewables are crippled by their intermittency, while nuclear power is reliable.

The Obama administration is concerned about the problem of nuclear waste management. But under the current system nuclear waste is stored safely, and poses far less of a danger to human health and safety and to the environment than waste from coal fired steam plants.

The Obama administration is overly concerned by nuclear safety, but by any objective standard America's 104 power reactors have proven to be extremely safe.

The Obama administration is concerned about nuclear costs, but the cost of making renewables reliable enough to assure America 24 hour a day power will make renewables more expensive than conventional nuclear power.

The Obama administration believes itself to be well informed about energy issues. In fact it is basing policy on half-baked energy approaches. The flaws in the renewable approaches now in favor should be clear to anyone who begins by asking obvious questions like where is the power going to come from when the wind does not blow, or when the sun goes down at night. And of course the Obama staff has not yet asked how much this is going to cost.

Barack Obama was elected to put an end to the non-deliberative policy approach of the Bush administration. So far, however, the Obama administration's attitude toward energy has been anything but fact based. Let us recall Ron Suskind's account of the Bush staffer:

The aide said that guys like me were "in what we call the reality-based community," which he defined as people who "believe that solutions emerge from your judicious study of discernible reality." ... "That's not the way the world really works anymore," he continued. "We're an empire now, and when we act, we create our own reality. And while you're studying that reality—judiciously, as you will—we'll act again, creating other new realities, which you can study too, and that's how things will sort out. We're history's actors…and you, all of you, will be left to just study what we do."

The Obama administration has not yet engaged in a judicious determination of the facts about energy. Confident in their own power and in their ability to set policy on whim, they have decided to follow what will surely be a disastrous policy if followed long term. We can only hope that during the next few years, as America's war to assure itself an energy future becomes obviously more difficult, and Mr. Obama's ability to see his own mistakes, admit them and correct them will come and prevent a disaster. If not we are headed out into the wilderness without food or water. Leading people toward disaster surely is not progressive.

The Economics of Renewable Energy Report by The House of Lords Economic Affairs Committee

I do not consider the report "The Economics of Renewable Energy" by the House of Lords Economic Affairs Committee to be a great report, although its authors attempted to deal in hard realities rather than simply repeating romantic myths about renewables. The Economic Affairs Committee simply acknowledged the limitations of renewables and their cost, and added an analysis of the cost effects working around the limitations.  I do however consider this report to be better than most similar studies on the subject, and I agree with most of its conclusions.   The sober and realistic analysis of this report stand is stark contrast to the Amory Lovinesque, fairy tale hype of Gristmill and Climate Progress.

Lest I be accused of cherry picking, I am going to quote the entire final chapter of the report together with supporting paragraphs from the report.

CHAPTER 7: RECOMMENDATIONS AND CONCLUSIONS

232. We cannot consider renewable energy in isolation from the rest of the UK energy system and we support measures to include nuclear plants as an essential element of the UK's energy mix (paragraph 74).
(74. All the cost estimates showed that nuclear power was cheaper than renewable energy. The cost of nuclear power is little affected by the oil price, although the uncertainty over the cost of decommissioning and waste disposal is a unique risk for nuclear stations. Nuclear plants have very low emissions and are not affected by changes in the cost of carbon. We cannot consider renewable energy in isolation from the rest of the UK energy system and we support measures to include nuclear plants as an essential element of the UK's energy mix.)
 
233. The cost of electricity from onshore wind farms at good locations would only be comparable with that from fossil fuel generators when the prices of oil, gas and coal are very high or allowance is made for the price imposed for carbon emissions permits (effectively a tax). It is more expensive than nuclear generated power—base cost 7 pence per kWh, as opposed to around 4 pence per kWh for the other technologies. Offshore wind, biomass, wave and tidal power are even more expensive. And these estimates exclude the additional costs of integrating more renewable generation into Britain's electricity grid (paragraph 74).

234. Future developments depend upon many variable factors But it seems clear that the base costs of generation of electricity from onshore wind are likely to remain considerably higher than those of fossil or nuclear generation and that costs of generation of marine or solar renewable electricity are higher still (paragraph 85). We hope that the Energy Technologies Institute's work will yield technological advance and lower costs. The Government should consider, perhaps in collaboration with others, offering a substantial annual prize for the best technological contribution to renewable energy development (paragraph 93).
(93. We hope that the ETI's work will yield technological advance and lower costs. The Government should consider, perhaps in collaboration with others, offering a substantial annual prize for the best technological contribution to renewable energy development. An initiative on these lines might help set the scene for a wider effort by the Government to encourage and promote research across on a range of technologies aimed at finding new and cost-efficient ways to reduce carbon emissions. We return to this theme in Chapter 6.)

235. Although their declared purpose is to improve the environment, it is clear that renewable energy installations can also have adverse environmental impacts which the Government should bear in mind as it weighs the benefits and costs of expansion of renewable generation (paragraph 96).

236. Fluctuations in wind speed lead to short term changes in electricity output from wind farms. Greater use of wind power and other intermittent renewable sources therefore requires more backup generation capacity to respond very quickly to, for example, reductions in the output of wind turbines when the wind drops. But the technical challenges and costs of backup generation on a scale large enough to balance an electricity system with a high proportion of intermittent renewable generation are still uncertain. Whereas the highest share of intermittent renewable electricity now being generated in Europe is 15% in Denmark, the UK is expected to reach a share of some 30%-40%. We recommend that the Government should ensure that further work is carried out to clarify the costs and encourage development of technical solutions to deal with intermittency (paragraph 104).

237. The need to part-load conventional plant to balance the fluctuations in wind output does not have a significant impact on the net carbon savings from wind generation (paragraph 105).
(105. Running a conventional plant at part load to provide spinning reserve reduces efficiency which leads to higher emissions per unit of electricity actually generated at that plant. Some commentators, such as Campbell Dunford of the Renewable Energy Foundation, argue that this might have offset the CO2 savings from renewable generation in Denmark. Denmark's carbon emissions per kWh generated have fluctuated from year to year, although the trend is steeply downwards, as set out in Appendix 7. Calculations based on the loss of efficiency from running a power station at part load, and the amount of extra reserve required, also suggest that the extra carbon emissions in the UK from additional spinning reserve would be very small in comparison to the savings from renewable generation. The Government has estimated the net saving from raising the share of renewable electricity to 32% to be about 45-50 million tonnes of carbon dioxide—about 8-9% of total CO2 emissions—after taking account of the cost of part-loading plant.[39] The need to part-load conventional plant to balance the fluctuations in wind output does not have a significant impact on the net carbon savings from wind generation.)

238. If some 30 GW of additional (Ev Q 487) renewable capacity were required to meet the EU's 2020 target for the UK a further 14-19 GW of new fossil fuel and nuclear capacity will still be needed to replace plants due to close and meet new demand. The total new installed electricity generating capacity required by 2020 would thus be roughly double the level needed if renewable generation were not expanded (paragraph 111). Investment in renewable generation capacity will therefore largely be in addition to, rather than a replacement for, the massive investment in fossil-fuel and nuclear plant required to replace the many power stations scheduled for closure by 2020. The scale and urgency of the investment required is formidable, as is the cost (paragraph 112).
(112. The intermittent nature of wind turbines and some other renewable generators means they can replace only a little of the capacity of fossil fuel and nuclear power plants, if security of supply is to be maintained. Investment in renewable generation capacity will therefore largely be in addition to, rather than a replacement for, the massive investment in fossil-fuel and nuclear plant required to replace the many power stations scheduled for closure by 2020. The scale and urgency of the investment required is formidable, as is the cost.)

239. A breakthrough in cost-effective electricity storage technology would help solve the problem of intermittency and remove a major stumbling block to wider use of renewable energy in the longer term. However, no evidence we received persuaded us that advances in storage technology would become available in time materially to affect the UK's generating requirements up to 2020. We recommend that the Government should as a matter of urgency encourage more research, development and demonstration in energy storage technologies (paragraph 117).

240. Our calculations suggest that the total extra annual cost of increasing the share of renewables in electricity generation from 6% to 34% in 2020 would be £6.8 billion or an extra 38%—the equivalent of an extra £80 a year for the average household. Emissions of carbon dioxide would be reduced by 52 million tonnes a year—in 2007, the UK's emissions were 544 million tonnes. This implies that the additional cost is about £130 per tonne of carbon dioxide emissions avoided (paragraph 128).

241. Ofgem is required to use competition wherever appropriate. We are concerned that the use of competitive tenders implies a piecemeal approach to building the networks of wires and cables required to connect offshore wind farms to the electricity grid, and that as a result the programme could become overly complex and costly. We recommend that Ofgem implements the new system in a way that allows a coordinated approach for organising grid connections to offshore wind farms (paragraph 131).
(131. We note that the regulator's statutory duties require the use of competition wherever appropriate, and therefore give it some discretion about the use of markets. Although competition is usually preferable, we are concerned that the use of competitive tenders implies a piecemeal approach to building the networks of wires and cables required to connect offshore wind farms to the electricity grid, and that as a result the programme could become overly complex and costly. We recommend that the regulator implements the new system in a way that allows a coordinated approach for organising grid connections to offshore wind farms.)

242. We welcome measures to organise better the queue of renewable generation projects awaiting connection to the electricity grid. They should reduce delays in connecting viable generation projects and push back schemes unlikely to get off the ground (paragraph 134).
(134. Ofgem and BERR have recently concluded a Transmission Access Review, which asked National Grid to take a more proactive approach to managing this queue, giving priority to projects that had received planning permission for their plant. Ofgem told us that National Grid is now taking a more robust approach to removing unviable or purely speculative projects (p 171). We welcome these measures to organise better the queue of renewable generation projects awaiting connection to the electricity grid. They should reduce delays in connecting viable generation projects and push back schemes unlikely to get off the ground.)

243. We consider that the current system of Transmission Use of System charges sends broadly appropriate signals of the costs of locating generators at different points on the system (paragraph 139).
(139. In the broader context, E.ON told us that charging for use of the transmission system should continue to reflect the costs to the system associated with generating from renewables and other generation at that location on the system. This would help ensure that these costs are taken into account in the decision where to site the project in the first place (p 108). But Scottish and Southern Energy, which has wind farms in remote parts of Scotland, argued against "the current perverse mechanism of regional charges". Ofgem has successfully defended a judicial review on the basis that "it was absolutely right that people who were at the extremities of the system should pay very high charges that reflected the economic costs of transmitting electricity a long way from where it is produced to where it is used" (Q 422). We agree with this position. We consider that the current system of Transmission Use of System charges sends broadly appropriate signals of the costs of locating generators at different points on the system.)

244. Greater interconnector capacity with the Continent would reduce, but not solve, the problems of intermittent renewable generation (paragraph 141).
(141. Greater inter-connectedness would allow Britain to tap renewable sources over a wider area which would reduce the problems with intermittency. For example, when the wind is blowing in Denmark but not Britain, electricity from Danish wind farms could then be imported. The wider the area of interconnectedness, the more likely it is that variations in wind patterns will cancel out, although the weather may sometimes be similar over even a wider area. For example, we received some evidence that low wind speeds in the UK could coincide with similar conditions in Germany, Ireland and even as far away as Spain.[46] Furthermore, it would not be economic to build enough interconnector capacity to solve our problems with intermittency, for wholesale electricity prices in the UK and on the Continent would then converge, whereas the interconnectors need different prices in the two markets to profit from trading between them. Greater interconnector capacity with the Continent would reduce, but not solve, the problems of intermittent renewable generation.)

245. Harnessing renewable sources of heat is often cheaper than for electricity generation and offers a larger target area, as heat accounts for double the final energy demand of electricity. There is no intermittency problem with renewable heat. We recommend that the Government should lay at least as much emphasis on encouraging the development and use of renewable heat as on renewable electricity generation (paragraph 163).
(Paragraph 245 simply repeated paragraph 163.)

246. We share the concerns raised in the Gallagher Review about existing biofuels. Steps should be taken towards developing second generation bio-fuels as soon as possible. Until the costs of carbon emissions reduction through biofuels come down we recommend that the Government should not seek to increase further the use of biofuels (paragraph 173).
(Paragraph 246 simply repeated paragraph 173.)

247. It is clear that, although the cost of the technology for carbon capture and storage (if and when it becomes a practical possibility) is inevitably highly speculative, it will always be more expensive than large-scale carbon-based energy without CCS (paragraph 177).
(177. It is clear that, although the cost of the technology for carbon capture and storage (if and when it becomes a practical possibility) is inevitably highly speculative, it will always be more expensive than large-scale carbon-based energy without CCS. Retrofitting the technology to stations not designed for it might be particularly expensive, but would be necessary to have a significant impact on the very large volume of emissions from existing plant.)
248. It seems clear there would be little investment in renewable energy without substantial Government support and that a 15% target would not be met without it (paragraph 183).
(Paragraph 248 simply repeated paragraph 183.)

249. We note the evidence that the cost per kWh of renewable electricity supported by the Renewables Obligation has been significantly higher than the amounts paid via feed-in tariffs abroad, and that much of the excess has been due to other differences in the environment for renewable generation, particularly in the planning system. However, given investors' need for a predictable framework, it seems right to retain the Renewables Obligation, if it is desired to continue increasing generation of electricity from renewable sources (paragraph 189).
(189. We note the evidence that the cost per kWh of renewable electricity supported by the Renewables Obligation has been significantly higher than the amounts paid via feed-in tariffs abroad, and that much of the excess has been due to other differences in the environment for renewable generation, particularly in the planning system. The renewables support mechanisms have already gone through a number of changes including the banding of the Renewables Obligation to give different levels of support to different forms of electricity generation. Introducing feed-in tariffs at this stage for large-scale generation[56] would create more uncertainty and risk deterring investment in the sector. Given investors' need for a predictable framework, it seems right to retain the Renewables Obligation, if it is desired to continue increasing generation of electricity from renewable sources.)

250. We are not persuaded that the wish of concerned citizens to make their own contribution to emissions reduction is an adequate justification for a public subsidy for micro-generation (paragraph 198).
(198. The Government supports micro-generation for reasons other than economics. Former energy minister Malcolm Wicks said: "If we were just focusing on the economics, we probably would not want to look seriously at micro-generation [but] many concerned citizens are asking how they can personally make a difference" (Q 503). We are not persuaded that the wish of concerned citizens to make their own contribution to emissions reduction is an adequate justification for a public subsidy to micro-generation.)

251. The returns from micro-generated electricity look too small and uneconomic for the Government to support. But the gains from households using micro-generated heat look much more promising. Government policy should focus instead on households generating renewable heat and on schemes that use renewable heat on a larger scale, such as those covering a housing development, or group of public buildings (paragraph 204).
(Paragraph 251 simply repeated paragraph 204.)

252. On the evidence submitted to us, renewable electricity is clearly more expensive than fossil fuel-fired and nuclear generation and leads to higher energy bills for consumers and businesses. We estimate that a household which consumes the average amount of electricity will have to pay in 2020 about £80 extra a year. The Government will need to take higher costs on board in framing its policies towards fuel poverty, noting the high correlation between fuel poverty and poorly-insulated homes (paragraph 208).

253. We call on the Government to look afresh at the UK's research effort into renewables and to consider what more might be done, in a global context, to promote more, and more focussed, research across a range of technologies leading to new, effective and economical ways to reduce carbon emissions (paragraph 213).
(213. The Committee heard that a much greater research and development effort is needed on renewables and other measures to cut carbon emissions. Professor Paul Ekins of King's College London argued for the equivalent of twin Manhattan projects—the scientific research programme which developed the atomic bomb. One would enhance energy efficiency, the other promote energy supply technologies including renewables. In his view, countries need to work together on this research. He said: "It is terribly important that we get globally the biggest bang for our buck and have properly coordinated basic scientific research." (Q 16). We draw attention (Paragraph 117) to the need for a greater research effort on electricity storage. We heard of research in areas ranging from floating marine turbines to solar thermal arrays in deserts. A substantial annual prize for research for the best technological contribution to renewable energy development, as recommended in paragraph 93, would symbolise the importance of applied research in the field. We call on the Government to look afresh at the UK's research effort into renewables and to consider what more might be done, in a global context, to promote more, and more focussed, research across a range of technologies leading to new, effective and economical ways to reduce carbon emissions.)

254. We recognise that power companies need a streamlined planning system to approve or reject projects more quickly. But local and national concerns about environmental degradation must also be addressed. It is important to ensure that the planning system adequately assesses the costs to local communities and the balance between national priorities and local decision-making. The Government should also examine how far local communities share in the economic benefits created by wind farm deployment and other renewable projects (paragraph 220).

255. We endorse the Government's objective of ensuring a secure, reliable and affordable supply of energy (paragraph 225).

256. The Government is right in stating that a portfolio of policies is needed to achieve this objective, if we are also to bring about reduced carbon emissions. Against a background of developing technologies and uncertain costs, the Government will need to give a firm lead, with clear priorities and realistic objectives, while maintaining the stable framework needed by investors in the context of the long lead times needed by many energy projects (paragraph 226).
(226. The Government is right in stating that a portfolio of policies is needed to achieve this objective, if we are also to bring about reduced carbon emissions. Renewable energy has a part to play, as does nuclear power, the only other currently existing source of low-carbon energy. Investment in conventional power (preferably equipped with CCS, if and when it becomes available) will also be needed, together with improvements in energy efficiency. Against a background of developing technologies and uncertain costs, the Government will need to give a firm lead, with clear priorities and realistic objectives, while maintaining the stable framework needed by investors in the context of the long lead times needed by many energy projects.)

257. We recognise that the Government has committed the UK to contribute to the EU target of 20% renewable energy by 2020 and that a target of 15% for this country is envisaged. But the bulk of the evidence presented to us casts doubt whether, under current policies and with current resources, it will be feasible to increase the share of renewable energy so much in the UK over the time available. This is especially so, as most of the growth is expected to occur in power generation, which represents only a fifth of the UK's energy use, and that this growth will be largely in addition to the substantial replacement programme of old conventional and nuclear plant that has to take place over the same time period (paragraph 228).

258. We are also concerned that determination to meet the target may lead to an over-emphasis on promoting short-term options, simply because they are available, rather than because they offer the most effective and economical means of reducing carbon dioxide emissions over the longer term (paragraph 229).

259. We have a particular concern over the prospective role of wind generated and other intermittent sources of electricity in the UK, in the absence of a break-through in electricity storage technology or the integration of the UK grid with that of continental Europe. Wind generation offers the most readily available short-term enhancement in renewable electricity and its base cost is relatively cheap. Yet the evidence presented to us implies that the full costs of wind generation (allowing for intermittency, back-up conventional plant and grid connection), although declining over time, remain significantly higher than those of conventional or nuclear generation (even before allowing for support costs and the environmental impacts of wind farms). Furthermore, the evidence suggests that the capacity credit of wind power (its probable power output at the time of need) is very low; so it cannot be relied upon to meet peak demand. Thus wind generation needs to be viewed largely as additional capacity to that which will need to be provided, in any event, by more reliable means (paragraph 230).

260. We consider that the Government, if it pursues a renewable energy target in addition to its targets for reducing carbon dioxide emissions across the board, should prioritise the development and promotion of the other effective and economic options, both to bring down carbon dioxide emissions and to achieve security of electricity supply. It will be important to ensure that incentives to promote those renewables which offer only intermittent supply do not divert attention from, and deter investment in, other low-carbon generation options and thereby risk power shortages. So far as reliability is concerned, the best options amongst renewable sources of generation are tidal barrage and biomass, which are problematic for other reasons, and hydro power, which is not, but is already near the limit of its potential in the UK. The most reliable low-carbon alternative to renewables is nuclear power (together with conventional fossil fuel generation with carbon capture and storage, if and when that becomes available) (paragraph 231).