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Floating offshore wind turbines are one of the big new ideas in the renewable energy field. They allow us to go far out to sea in deep water in which would be impossible, or vastly expensive, to install devices fixed to the sea-bed. They also avoid the environmental intrusion of sea bed foundations or monopiles.

There is a range of systems being tested, many of them owing much to experience with offshore oil and gas rigs. So perhaps it's not surprising that the leaders in the field are the Norwegians. Statoil/Norsk Hydro have developed and tested a 2.3 MW Hywind system in water 220 metres deep off the coast of Norway, while Sway is developing a novel 10MW floating turbine. They both are essentially like the vertical bobbing floats used for fishing, with a long tail under the water providing buoyancy and supporting a conventional propeller-type wind turbine above the water line. They are kept vertical by sea-bed tethers, although the Sway system is designed to be able tilt by up to 8 degrees. http://www.sway.no http://www.statoil.com/en/TechnologyInnovation/NewEnergy/RenewablePowerProduction/Pages/default.aspx

The Dutch have also developed a tension leg platform system, based on oil rig technology, called Blue H. http://www.bluehusa.com/ A prototype is being tested in the Mediterranean- in 108 meters waters at a distance of 10.6 nautical miles from the coast of Puglia in Southern Italy. France plans to install four floating offshore wind turbines and a 3.5 MW. Blue H is a candidate.

The UK is also in the race. Engineering firm Arup is working with an academic consortium backed by Rolls Royce, Shell and BP and linked to architects Grimshaw, on a 10MW "Aerogenerator X", a novel V- shaped vertical axis floating offshore wind machine, measuring 300m from blade tip to tip. The first unit could be ready in 2013-14. See http://www.windpower.ltd.uk/ and http://vimeo.com/13654447

This grew out of the NOVA (Novel Offshore Vertical Axis) project, backed by the Energy Technology Institute (ETI) and involving Cranfield University, QinetiQ, Strathclyde University, Sheffield University. http://www.nova-project.co.uk/

The ETI has also funded development work on a concrete version of the Blue H design, with involvement from amongst others BAE Systems. In parallel US wind company Clipper, is planning to build the more conventional 7.5 MW "Britannia" deep-sea offshore turbine in north-east England in conjunction with NaREC, the New and Renewable Energy Centre. The first in UK waters though could be a version of Hywind- Statoil is planning to build an offshore wind farm using 3 to 5 floating turbines developed for its HyWind project off the northeast coast of Scotland.

Feargal Brennan, head of offshore engineering at Cranfield University, where much of the Aerogenerator X development work has been carried out, told the Guardian (26/7/10) 'There is a wonderful race on. It's very tight and the prize is domination of the global offshore wind energy market. The UK has come late to the race, but with 40 years of oil and gas experience we have the chance to lead the world. The new [Aero-generator] turbine is based on semi-submersible oil platform technology and does not have the same weight constraints as a normal wind turbine. The radical new design is half the height of an equivalent [conventional] turbine.' He added that the design could be expanded to produce turbines that generated 20MW or more.

Bigger machine have both advantages and problems. Doubling the diameter leads to four times as much power, but eight times as much weight and can also increase costs by a factor of eight. However vertical axis machines may be lighter, since they need no tower, and may also have the advantage of easier maintenance access and higher stability in high winds.

The USA, so far rather back-ward in developing off shore wind, has now also got into the race. One argument had been that, unlike the UK, which has shallow water offshore (with 1 GW of offshore wind now in place), US coastal waters were deep, so that offshore wind wasn't very practical. There were also environmental and visual intrusion objections to location near-shore. For example the wind farm proposed for off Cape Cod has only just now been given the go ahead after 10 years of regulatory and legal battles. It will be the USA first offshore wind project. But deepwater floating turbines may change the game.

The US National Science Foundation, has now funded a 3 year project to see if the construction of floating wind turbines in the deep- ocean is a viable. And the State of Maine has just proposed a plan for installing up to 30MW of deepwater marine power, of which only 5MW can be tidal the rest being wind, which must be floating -and be expandable to 100MW or more. Hywind is said to be a candidate.

Back in the UK, the potential for floating offshore wind is very large.. The PIRC Offshore Valuation puts the practical potential at 870TWh/yr, with 660TWh/yr more beyond 100nm out. In all, that's about four times UK electricity consumption. www.offshorevaluation.org

Of course location that far out will mean that the cost of the undersea grid links will be high, but deep sea wind seems likely to become increasingly attractive as a north sea supergrid network is established, with new UK- to-continental HVDC power grids linking in offshore wind farms across the area, helping the balance local and regional variations in wind availability.

For updates on renewable energy developments in the UK and elsewhere see : www.natta-renew.org

A Desertec 'energy from the deserts' initiative was launched last year as a feasibility study by a group of major German energy companies and banks keen to install large Concentrating Solar Power (CSP) arrays in desert areas and transmit some of the power back to the EU by undersea High Voltage Direct Current supergrids.

Desertec is not the only player however. Transgreen is a new French led supergrid project now being developed as part of the Mediterranean Union's Solar Med programme. Solar Med includes proposals for installing 20 Gigawatts (GW) of renewables by 2020, using a mix of technologies: around 6GW of wind, 5.5GW of CSP and nearly 1GW of PV solar in North Africa and the Middle east. And to link it up the Mediterranean Union has proposed a 'Mediterranean Ring' - a grid system linking up countries around the Med, including power from CSP in North Africa/the Middle East being transmitted to the EU via HVDC links under the sea.

That's where Transgreen comes in. It might be seen as a rival to the German-led Desertec project, given that Transgreen's aim is to bring together power companies, network operators and high-tension equipment makers under the leadership of French energy giant EDF. But the idea seems to be that Transgreen will focus on transmission, and just deliver part of the energy generated by the Desertec CSP projects to the EU- and there is already some overlapping membership. A €5m study phase is underway.

The energy potential for CSP is huge- there is a lot of desert! There is talk of 200GW or more eventually being installed. The technology exists (in Spain and the USA) and its economics and performance is improving, with molten salt heat stores allowing for continued use of solar power overnight. So CSP could become a large-scale reality, while HVDC transmission losses are put a 1-2 % per 1000km, so long distance export seems credible. An EU commissioner recently said that the first power could arrive in the EU in 5 years.

However, despite talk of a $400bn programme, at present the Desertec initiative is only just a concept- not yet a formally funded project, although some independent CSP projects are already underway e.g. in Egypt, Jordon Algeria and Morocco, which could become part of it. A 470 Megawatt (MW) hybrid solar/ gas fired unit, with 22 MW of CSP, has just been started up in Morocco, Egypt is nearing completion of a €250m 150MW hybrid unit near Cairo, while the UAE has plans for 1000MW CSP unit.

These and other projects may of course just stay independent, at least initially and not export any power. After all, Transgreen too is only just starting up as a concept. And there will certainly be some interesting routing issues for it face. For example, does the proposed French Transgreen link-up to Morocco have to go across Spain, or can it go undersea direct? That's much more expensive, 1200km of marine cable at maybe €1m/km, rather than two stretches of 200km undersea. The trans-Spain option does also allow Spanish wind power to be fed in, but the undersea line avoids land use and local or regional or indeed national political conflicts. Spain has recently had a major a battle getting a HVDC grid link across the Pyrenees to France. It had to be put underground, at increased cost- although it's worth noting that it is evidently easier to put HVDC cables underground than conventional AC grid links, since there are less heat losses to deal with.

There are also some wider regional and indeed international political issues. We have suffered enough from the politics of oil, it is to be hoped that the politics of solar would be different.But there is the risk of a neocolonial resource grab- with investors rushing to get sites in North Africa and the Middle East and then seeking to get access to the power at favorable rates. At the very least it will be important to negotiate fair trading arrangements. However there is also a need to consider what is wanted locally. While the EU media has often waxed lyrical about the concept of power from the desert, some of the countries who would be the likely hosts to CSP projects to supply the supergrid, evidently feel they had not been sufficiently consulted. They may have their own views.

The trade journal Sun and Wind recently carried an interview with a leading Egyptian renewable energy supporter, Prof. Amin Mobarak, and others involved with a Masters course run jointly by the Universities of Kassel and Cairo, aiming to help local people to get on top of the technical and political issues associated with CSP. (Sun and Wind 5/20/10). One point that emerged was that the use of CSP for the desalination of water might be more important locally than electricity production (That actually is part of the Desertec plan). In addition, electricity demand was rising rapidly in the region, so there might not actually be that much spare for the EU! However, electricity prices were often subsidised locally (e.g. in Egypt) for social policy reasons, and that would be hard to change. So, initially at least, the relatively high price of CSP power might mean that it could only realistically be sold abroad.

But then comes the accreditation issue. EU Commissioner Guenther Oettinger recently said that, to avoid the import of non-renewable electricity from coal and gas-fired plant in north Africa, 'we need ways to ensure that our import of electricity is from renewables' However he believed it was technically possible to monitor electricity imports to the EU to see if they came from renewables. It is not immediately obvious how. And of course there is the wider question of overall security of supply: if it was getting 15% of its electricity from desert project, as Desertec plans, the EU would not want to risk being cut off. Plenty of issues to haggle over then- quite apart from the issue of local environmental impacts on fragile desert ecosystems. That has already led to some limitations on projects in the USA in relation to the protection of desert wildlife.

Some argue that we should not import green power, but should focus on our own resources in the EU. Certainly we should not use remote desert CSP as an excuse not to develop our own extensive renewable resources as fast as we can- large and small, locally and nationally. However a fully integrated supergrid system, including links to offshore wind, wave and tidal in the North West, as well as to CSP in desert areas, could offer benefits to all, in terms of helping to balance variations in the availability of renewable energy around the entire region. And locally, CSP could offer power, fresh water, jobs and income. Moreover, as far as the planet is concerned, it doesn't matter where the projects are located, as long as they reduce/avoid emissions. If the best sites for solar are in desert areas, so be it. But politics and economics intervene. The CSP/supergrid concept opens up range of new- and old- geopolitical and development issues. Not least who gets the power, and at what cost, and who gets the profits.

Parts of the above are from my presentation to a Summer Academy on 'Transnational Energy Grids' at Greifswald University, Germany, in July.

The Department of Energy and Climate Change has produced a new DIY energy supply-and-demand model, running up to 2050, developed under the supervision of Prof. David MacKay, DECC's chief scientific advisor. You can try it out: http://2050-calculator-tool.decc.gov.uk/.

It allows you to vary the energy supply mix so as to try to meet emission targets in line with various possible demand patterns, including charging electric car batteries overnight. Following the line adopted in earlier DECC scenarios, what emerges is that it's hard to stay in balance and get emissions down, without nuclear and Carbon Capture and Storage (CCS). The model tests the ability of the chosen supply mix to meet demand during a five-day anticyclone, with five days of low wind output and an increase in heating demand associated with the cold weather. But there are ways to balance variations like this, and the DECC report on '2050 energy pathways', which sets the model in context, does explore some of these options.

Even so, it concludes that, if CCS is not widely used, 'because of the large amount of renewables in this pathway, the challenges of balancing the electricity grid in the event of a five-day peak in heating and a drop in wind are more substantial. We would need a very significant increase in energy storage capacity, demand shifting and interconnection, together with 5GW of fossil-fuel-powered standby generation that would be inactive for most of the year.' And if nuclear was not used, 'the challenges of balancing the electricity grid are very substantial: we would need an extremely substantial increase in storage, demand shifting and interconnection'. By contrast 'without renewables in the system, it is easier to balance the electricity grid and no additional back-up capacity beyond what exists today is required'. Nuclear then dominates, and, DECC seems to say, that path gives lowest overall costs long term.

www.decc.gov.uk/en/content/cms/what_we_do/lc_uk/2050/2050.aspx

Not everyone may agree with that. Indeed, Chris Huhne, the new Lib Dem Energy and Climate Change Secretary of State, is on record as saying that nuclear economics means that it will need state support to be competitive – something he and the coalition government were not prepared to provide. A recent version of this view was his response to Lord Marlands statement on behalf of the government that 'there should be no dramatic increase' in current plans for around 14GW of on land wind power. Defending wind, Huhne commented: 'We have seen that with onshore wind, whose cost has come down dramatically precisely because of the encouragement of the public sector. I am afraid that the same argument cannot be made for nuclear power, which has been around for a long time. It is not an infant industry, but an established and mature one and it can and should compete on that basis, along with all other comers.'

However he seems to have been under pressure to back nuclear none the less. In a letter to The Financial Times (4 Aug) he said: 'Given our policy framework, and the outlook for oil, gas and carbon prices, I am nevertheless confident that there will be new nuclear power as planned by 2018.'

He went on: 'What nuclear will not have – and this is common across all three parties in Britain – is public subsidy specific to the industry.' But there will – or could – be a susbsidy, in all but name, in the form of a floor price for carbon, which will benefit all non and low carbon options.

So what could actually emerge? DECC's 2050 Pathways are not based on funding or support programmes, but simply offer four different 'levels' of possible technical response – from more or less none (1) to the absolute maximum (4), and then uses that as a basis for assembling a range of pathways with different mixes on both the supply and demand side, on the way to 2050.

Focusing here just on the supply side, on land wind comes out reasonably well with, by 2050, at Level 2, it being assumed that there could be 20 GW in place (delivering 55TWh of electricity then); at Level 3, 32GW (delivering 84TWh) and at the maximum Level 4, 50GW (132TWh). But offshore wind does much better – 60GW (delivering 184TWh) at Level 2,100GW (307TWh) at Level 3 and a massive 140 GW (430 TWh) at level 4. Wave/tidal stream devices do quite well at, respectively, 11.5GW (delivering 25TWh), 29 GW (68 TWh) and, at maximum, 58 GW (139 TWh), with wave leading tidal currents up to Level 4, when wave is put at 70TWh, tidal stream at 69TWh. But Tidal Range projects (barrages and lagoons) only manage, respectively, 1.7GW (3.4TWh), 13 GW (6TWh), and 20 GW (40 TWh) at Level 4 – significantly less than either wave or tidal stream in each case.

PV solar comes out of almost nowhere to yield, by 2050, 80 TWh at Level 3 and a massive 140 TWh at Level 4, although DECC is at pains to point out that the latter is very ambitious, expansion of this scale presenting 'an unprecedented challenge'. In addition, small-scale wind only delivers 8.6 TWh/yr max, while geothermal reaches just 5 GW by 2030 at Level 4, and hydro moves up to 4 GW in Level 4.

More radically, by 2050, there are 140 TWh of imports from Concentrating Solar Power in desert areas, covering 5000 sq km, in level 4. It's assumed that the UK's share of this is 20%. There are also some imports of biomass – at the maximum, around 135 TWh each of wet and dry biofuels, by 2050.

In terms of grid balancing for variable renewables, DECC notes that, being relatively inflexible, neither nuclear or CCS can be relied on for very large balancing capacity. So it looks to others options – energy storage, new grid interconnections to and from the continent, and flexibility (e.g. by using the proposed electric vehicles (EVs) or plug-in hydbrid electric vehicles (PHEV) car battery fleet as an overnight store). At Level 3 the storage capacity peak output increases to 7 GW by 2050. Interconnection increases to 15 GW, and around a half of all EVs and PHEVs have a shiftable electricity demand capacity. At Level 4, storage capacity peak output reaches 20 GW, interconnection 30 GW; and 75% of all EVs' and 90% of all PHEVs' storage capacity are utilised for shifting demand.

Finally there's nuclear. While at Level 1 it is assumed that 'the Government no longer wishes to take new nuclear forward and that a lack of clarity over planning and licensing timescales would lead to no planning applications coming forward and potentially the suspension of activities at sites where planning applications had been submitted'. At Level 2 there would be 'continued government and public support for new nuclear and that the facilitative actions would progress', with a total capacity of 39 GW at 2050 delivering 275 TWh of electricity per year with a build rate of just over 1GW/year. (Interestingly, by comparison, it notes that in Germany in recent years the build rate for wind has averaged around 2.1 GW/year.)

At Level 3, a nuclear build rate of 3 GW/year is achievable from 2025, leading to 90 GW at 2050 (633 TWh). And at Level 4 we move from a build rate of 3 GW/yr up to 2025 to a max of 5 GW/yr thereafter, with government interventions being needed, so that 146 GW in reached at 2050, delivering 1025 TWh. But we couldn't do that by ourselves – we would need overseas help!

Looking 40 years ahead is risky and hard to cost, but it's a brave effort, especially as it also tries to cover a range of heat suppliers, like solar, and end-use sectors, including transport. There is a call for evidence and there will no doubt be plenty of debate on the details and the viability and desirability of some of the Level 4 suggestions, not least of 146GW of nuclear!

The EU is set to contribute 45% of the construction costs for ITER, the new international fusion reactor being built in France, which some estimates now put at €15 bn, three times the 2006 cost estimate. But the EU's financial problems may mean that it can't deliver all of its share of around €7.2 bn.

The most pressing problem is a €1.4 bn gap in Europe's budget for ITER in 2012–13. Nature commented: "Left unresolved, the impasse in Europe will, at best, delay the project further. At worst, it could cause ITER to unravel entirely." It added: "The crunch is so serious that some European states have gone as far as to ask the commission to investigate the possibility of withdrawing from ITER, according to sources familiar with the negotiations. The price of such a withdrawal would probably be in the billions, as the treaty governing ITER requires heavy compensation to other partners."

A temporary solution would be a loan from the European Investment Bank to cover the immediate €1.4 bn budget gap. Another possibility would be to build a smaller version. But that could compromise its viability and aims.

Following a crisis meeting in July, it now seems that some interim refinancing has been agreed, but details of who is paying more are scare. However, the larger point remains. As Stephen Dean, president of Fusion Power Associates, a US non-profit advocacy group, told Nature: "There are serious questions about the affordability of fusion as a whole as a result of ITER."

On their website, Fusion Power Associates say that: "It would be premature at this stage to judge which of the variety of magnetic and inertial fusion concepts will ultimately succeed commercially." But, although part of the ITER magnetic containment programme, the US is also pushing laser-powered inertia fusion strongly these days, while the UK is also the base for an international HiPER laser fusion project.

HiPER is being supported by a consortium of 25 institutions from 11 nations, including representation at a national level from six countries. Following positive reviews from the EC in July 2007, the preparatory phase project will run up to 2011, aiming to establish the scientific and business case for full-scale development of the HiPER laser fusion facility. This phase is timed to coincide with the anticipated achievement of laser fusion ignition and energy gain (on the National Ignition Facility laser in the US). Then the website says "…future phases can proceed on the basis of demonstrable evidence. Construction of the HiPER facility is envisaged to start mid-decade, with operation in the early 2020s…", possibly at Rutherford Appleton Lab in Oxfordshire, since the UK is a leading contender to host the HiPER laser facility.

The physics is tricky, but the engineering is even more so – 1 mm pellets of deuterium and tritium have to be presented accurately and fired by lasers continually, many times a second, and the debris cleared away. But the HiPer group seems confident it can be done and that inertial fusion may be easier than the "magnetic containment" fusion approach being adopted by the ITER project. They say that "Inertial fusion offers some unique benefits – for example the potential to use advanced fuels (with little or no tritium). This greatly reduces the complexity of the process and further reduces the residual radioactivity. Inertial Fusion also allows for the use of flowing liquid wall chambers, thus overcoming a principal challenge: how to construct a chamber to withstand thermonuclear temperatures for the lifetime of a commercial reactor. In addition, Inertial Fusion allows for the direct conversion of the fusion products into electricity. This avoids the process of heating water, and so increases the net efficiency of the electricity generation process." It would be good to hear more about that. Otherwise it's back to running pipes through the outer blanket to raise steam!

Interestingly though, electricity production may not be the main aim. As with other fusion projects, and some new fission projects, there is now talk of focusing more on hydrogen or synfuel production (e.g. for the transport sector, presumably either by electrolysis or by using the heat direct for high-temperature dissociation of water). Or the heat could be used for other industrial processing heating purposes.

Whatever the final end-use, the engineering does sound mind-boggling, even if the Hiper website does try to make it seem familiar: "The principle is conceptually similar to a combustion engine – a fuel compression stage and an ignition stage" (i.e. "analogous to a petrol engine (compression plus spark plug) approach").

Well yes, but it's at 100 million  °C, and, after a few firings, the whole thing will become fiercely radioactive due to the blast of neutrons that will be produced.

They are also the source of the energy that would have to be tapped if power is to be produced. But this bombardment means that, as with ITER, the containment materials and other components will be activated by the neutron flux, and have to be stripped out periodically and stored somewhere, although the half-lives would be relatively short – decades. The radioactive tritium in the reactor also represents a hazard; although the quantities at any one time would be small, accidental release could be very serious.

Overall it all sounds very complex and daunting and not a little worrying. On current plans we might be seeing a prototype working in the 2030s, although that sounds a little optimistic. Meanwhile, other ideas may yet emerge. There is talk of hybrid fusion/fission systems – perhaps using the neutron flux to convert thorium into a fissile material, or to transmute some of the active wastes from fission. And there was me thinking that fusion was meant to replace fission – not support it!

The UK is spending about half its energy R&D budget on fusion, including a contribution via EURATOM to ITER, as well as its national programme (£20 m last year), following on from JET at Culham. HiPER may achieve an earlier breakthrough than ITER, but the UK Atomic Energy Authority has said that, assuming all goes well with ITER and the follow up plants that will be needed before anything like commercial scale is reached, fusion only "has the potential to supply 20% of the world's electricity by the year 2100". Renewables already supply that now globally, including hydro, and the new renewables like wind, solar, tidal and wave power, are moving ahead rapidly – and could be accelerated.

As I said in a previous blog, since we need to start responding to the climate problem now, it might make more sense to speed the development and deployment of full range of renewable technologies, and make use of the free energy we get from fusion reactor we already have – the sun.

http://fusionpower.org/

http://www.hiper-laser.org

In 1997, 'Factor Four: Doubling Wealth, Halving Resource Use' by Ernst von Weizsäcker, Amory Lovins and L. Hunter Lovins, agued that technical innovation could cut resource use in half while doubling wealth. A new book, upgraded to 'Factor Five', builds on this idea- looking at how and where factor four gains have been made in the intervening period, and at how we might achieve greater factor five or 80%+ improvements in resource and energy productivity in future, in line with IPCCs recommended target of 80% reductions in greenhouse gas emissions.

It provides an overview of efficiency opportunities across a range of sectors. The approach is very positive and optimistic, making it hard to make any criticisms without appearing churlish, as with a most work from what is now sometimes called the Amory Lovins school of analysis. But it ought to be asked- aren't there limits to what can be achieved by energy efficiency? Using fuels more efficiently, in terms of both their conversion and consumption, means less emissions for the same amount of energy finally used. So obviously that's a priority. Investing in efficiency is also often seen as an economically attractive option. It is certainly true that, in the past, since fuels have often been relatively abundant and cheap, we have not paid much attention to their efficient use. So there is a lot of potential for cheap and easy energy saving options which we can and should exploit. Initial Factor 5 gains seem not unreasonable expectations. However once these 'low hanging fruit' options have been exhausted, there will surely be diminishing returns: it will, in many cases, be progressively harder and more expensive to make further savings.

This is where there is a key disagreement. The Lovins school view seems to be that costs of energy saving will continue to fall as new technology emerges. It is certainly true that for most mass-produced items, prices do fall from the initially expensive first versions- think of DVD players. It's the classic learning curve model. But it's not true of all products- e.g. cars are getting more efficient, but also more expensive.

Can Factor 5 type efficiency/resource savings continue to be made across the board, with costs continually reducing? Especially also given the rebound effect- with cost savings from efficiency often being used to buy more energy services, so undermining the emission savings. The new Factor 5 book does recognise this issue (Lovins tends to have dismissed it in the past as 'small') but suggests that the way out is to ramp up prices of fuels and resources to squeeze out consumption and steer consumers to the use of less energy and resource intensive options, including renewables. Certainly, if the money saved from efficiency is invested in renewables, then you capture all the emissions savings. And, like Factor 4, the new Factor 5 analysis does include the use of renewables- it's a key part of their programme. After all, quite apart from the rebound issue, that is where we might expect some major 'Factor 5' emission savings, i.e. from the widespread use of renewable energy supplies, although not necessarily with ever-diminishing costs. Clearly, whatever we do to improve efficiency, there will still be a need for new energy sources, as the availability of fossil fuels declines, and as we seek to avoid using them, for environmental reasons. But there are ecological and resource limits to how much we can get from renewables, and that means an acceptance of the need to curtail consumption at some point.

Whereas Lovins sometimes seems to have implied that we can all have more of everything, the new book challenge the simple 'win-win-win' belief that we can expect reduced costs and emissions while continuing to expand material consumption: it talks of rising eco-taxes and a focus on qualitative 'well being' in a more equitable world - a much more palatable, if maybe a little utopian, version of win-win-win, which most of us would no doubt be happy to sign up to. Growth may be vital for some developing economies in the medium term to allow populations to move beyond subsistence level, but it can't go on forever, everywhere. The result, after all, does not bear thinking of- endless material growth in an increasingly fractious and alienated global society, until it all shudders to a social and ecological halt. Much as the Dark Mountain group fears: for their rather different view on how we should respond, see www.dark-mountain.net

The above is based on my review in issue 186 of Renew: http://www.natta-renew.org

John Etherington's The Wind Farm Scam – an ecologist's evaluation (Stacey International, London, 2009) is evidently seen as a definitive text by anti-wind groups. You don't have to read much of it to see why. Here are a few quotes. He says that the wind power industry is determined "…to drive roadway after roadway through lonely places, to dump concrete in enormous quantity, to bulldoze acres of hillside into wind farms studded with gigantic, identically mass-produced steel and plastic monsters. This is akin to demolishing the great cathedrals for road stone or shredding the contents of the National Gallery to make wall insulation".

He says that "…as the developers have grabbed the remote lands of Britain, so their flailing blades perforce creep closer to habitations". He describes windfarm turbines as "wind monsters" spreading "environmental harm" and sees anti-wind campaigners as "the heroic defenders of the land". And, rather than "twitching crucifixions of landscape", he recommends, as an alternative, nuclear power, which he claims "could give secure supply of very large amounts of electricity". For good measure he's also a bit of a contrarian on climate change: he feels that: "It is not credible that the virtual-world output of the models can reliably be used to make policy decision."

So can this book be ignored as just a silly opinionated diatribe? Unfortunately no, since John Etherington is an ecologist and academic of some standing, having been reader in ecology at the University of Wales, Cardiff, and a former editor of The Ecologist. And the bulk of the book consist of a well written and detailed account of wind power – how it works and what problems there might be – with much of this being respectably done, even if there are occasional lapses and errors. Some of the errors are technical – he is not an engineer and occasionally slips up on details, some of which are important.

Fortunately Prof. John Twidell has provided a detailed critique, pointing out the errors and misunderstandings, in a review in Wind Engineering, Vol. 34, Issue 3, pp 335-350' , 2010. For example, Twidell notes that, in his account of the impact of variable inputs from wind turbines on the grid, Etherington fails to mention that demand is constantly changing, and that supply has to be altered to match the demand. This omission is serious, since the impression is given that variations as from wind power are distinct and previously unknown, whereas the variations due to changes in load have always been similar and predominantly more extreme. Thus a grid that copes with load/demand variation, copes easily with the arrival of wind power. A similar unforgivable error is not to mention that all forms of generation fail and hence need back-up strategies. Maintaining short-term operating reserve capacity with a range of mechanisms to balance supply and demand have always been the central tasks for grid operators.'

There are many more such examples of omissions or errors, which are catalogued in detail in Twidell's 8,000 word assessment, along with some statements which can only be described as disingenous: Etherington describes the various ways in which wind projects have been financed, with most (like the Renewable Obligation and Feed In Tariffs) passing the costs on to consumers. Nothing new there – it's all well known. So how can he then complain about "huge and concealed benefits to the wind power developers and covert arrangements which prevent this from being common knowledge"?

Twidell's review deserves to be widely read – it's a carefully measured analysis, which strives to keep irritation at the anti-wind rhetoric in check. He even rather kindly offers a let-out at the end: "Visual impact and its psychological implications is probably the key to understanding the divisions exposed by this book; every other criticism from Etherington and his colleagues probably flows from this problem." Other readers may not be so kind.

Even so, despite its often hectoring tone, this book deserves to be read: some wind-power enthusiasts do overstate their case, there certainly can be problems with managing wind systems, and it is always useful to have beliefs and certainties challenged, especially since, on most plans, many countries around the world now expect to rely on wind for large parts of their energy input in the years ahead. In addition, this book may also serve as a timely reminder to us all, whatever our beliefs, that "purple prose" and rhetoric do not sit well with, and can undermine, more careful analysis. And that is something that can apply to "greens" as well as to contrarians.

You can access Twidell's review at www.embracemyplanet.com/critique-wind-farm-scam.

For more on renewable-energy policy and issues, visit www.natta-renew.org.

"We advocate inverting and fragmenting the conventional approach: accepting that taming climate change will only be achieved successfully as a benefit contingent upon other goals that are politically attractive and relentlessly pragmatic. Without a fundamental re-framing of the issue, new mandates will not be granted for any fresh courses of action, even good ones".

That's the line adopted in the Hartwell report, by an international group of academics co-ordinated by the London School of Economics. They claim that 'it is now plain that it is not possible to have a climate policy that has emissions reductions as the all encompassing goal'. They note that 'in particular the ambitions for regional- let alone global - "Cap & Trade" regimes to regulate carbon by price, can be now seen to have been barren in their stated aims although profitable for some in unexpected and unwelcome ways.'

They say that in any case we shouldn't just be focussing on climate change: 'there are many other reasons why the decarbonisation of the global economy is highly desirable'. In the approach they would like to see 'decarbonisation is achieved as a by-product of pursuing more pragmatic and popular primary goals, including expanding energy access, energy security and, ultimately, making energy less expensive and more abundant.'

They also claim that we have focussed too much on carbon. So for example they want vigorous and early action on non-CO2 climate forcing agents like black carbon and tropospheric ozone. But their main overall concern is to rebuild public trust via successful improvements in energy efficiency and new energy innovation which clearly cut costs. So they want to develop 'non-carbon energy supplies at unsubsidised costs less than those using fossil fuels' and advocate funding this work by 'low' hypothecated (dedicated) carbon taxes.

However they say that there is a way to go: renewables are still mostly expensive, 'except under the best of circumstances, i.e. when located at optimal sites; close to existing transmission lines; displacing peak generation rather than base load, and serving a constituency willing to pay higher prices'. In passing, they manage a dig at 'the chilling history of European and particularly British wind-power, recently', which has 'led to poorly-chosen wind facilities that have performed much less well than promised, with serious financial and social consequences because they also distort overall portfolio investment decisions in significant ways'

Clearly they see carbon taxes, as being better than government subsidies, which is evidently what they see as being the basis of the EU approach. In fact, at present, RD&D apart, there are not many EU government subsidies - the UK's RO, the Feed In Tariffs in the EU, and even the EU Emission Trading System, are all in the end supported by extra charges levied by supply companies on consumers - not by taxpayers.

While the authors clearly don't like subsidies, really though their fundamental objection to current climate policy is much wider. They say 'energy policy and climate policy are not the same thing. Although they are intimately related, neither can satisfactorily be reduced to the other. Energy policy should focus on securing reliable and sustainable low-cost supply, and, as a matter of human dignity, attend directly to the development demands from the world's poorest people, especially their present lack of clean, reliable and affordable energy. One important reason that more than 1.5 billion people presently lack access to electricity is that energy simply costs too much'.

This sounds a little disingenous- there will be precious little dignity if climate impacts turn out to be as bad as expected. Carbon and other emission have to be dealt with- and fast. What the Hartwell report is claiming is that it is no good focussing on emission targets, in part since, as was stated in an earlier comment from the team quoted in the report "It is a characteristic of open systems of high complexity and with many ill-understood feed-back effects, such as the global climate classically is, that there are no self- declaring indicators which tell the policy maker when enough knowledge has been accumulated to make it sensible to move into action. Nor, it might be argued, can a policy-maker ever possess the type of knowledge - distributed, fragmented, private; and certainly not in sufficient coherence or quantity - to make accurate 'top down' directions."

So do we just leave it to the market? The authors seem to think so, in terms of choosing which way to go: 'Driving cost reductions must be the explicit purpose and primary design of deployment policies. Achieving consistent reductions in the unsubsidised cost of clean energy technologies must be the measure that determines which technologies will fly and which will stall in the long term'. But it can't, they say, just be left to the free market: 'since much of the energy technology revolution will require…basic RDD&D investment, public funding on a long-term basis is essential; and that is why an hypothecated tax is so important'.

A bit confusing since later they say 'innovation activities will of necessity be sponsored initially by the public sector' i.e. a short-term input. But what they are adamant about is that the carbon tax must not try 'to alter short-term consumption behaviour'. They were clearly chastened by the spectacular failure and withdrawl of the ambitious Carbon Tax proposed for France by President Sarkozy. Theirs would be lower and just for technology push. But then it sounds like they hate government dictats of any sort, and only accept government intervention and support grudgingly, since the private sector won't fund much R&D.

Overall, the carbon tax aside, their approach seems to have much in common with that adopted by the US and China at COP 15 - a free market technology-led approach, with no binding emissions targets, or government edicts. That may not be too surprising when you look at some of the sponsored of the report- who include the Japan Iron and Steel Federation, and the Japan Automobile Manufacturers Association.

Leaving conflicting ideological views on markets aside, of course more needs to be done across the board - the Kyoto approach was marginal at best. However, it's not clear the Hartwell approach is any better. A carbon tax would increase consumer energy bills, and most studies suggests that, although, in time, the transition to renewables will reduce prices, initially it may not.

Some have also seen the reports emphasis on non-CO2 emissions as odd. Dr Bill Hare, from the Potsdam Institute for Climate Impact Research, commented that 'The paper's focus away from CO2 is misguided, short-sighted and probably wrong'.

And underlying it all is a belief that technical fixes are the answer, while social and behavioural change is likely to be hard. The latter is clearly true, but that doesn't mean we shouldn't try to do both. Technical fixes may well work in the short to medium term , but is it really realistic to expect continually reducing costs, and perhaps more importantly, continually expanding energy use, long term? Energy efficiency and renewables can allow us to expand energy use up to a point, but there are limits. We also need to start thinking about sustainable consumption.

The Hartwell Paper: A new direction for climate policy after the crash of 2009

Technology guru Bill Gates of Microsoft fame gave a sparkling presentation on energy back in February, under the title 'Innovating to Zero' (i.e. zero emissions).

Oddly he repeated the old saw about renewables being expensive and needing a lot of backup. Strange given that ,in California, wind power is the cheapest energy source on the grid and the main issue in the US is not so much the intermittency of wind as there often being too much wind generated electricity for the grid to handle (see my earlier blog on curtailment issues).

And even more oddly, he didn't mention the smart supergrid idea, which could balance and manage local variations in supply and demand. You might think that would be right up his street, as someone who pioneered internet information grid systems and applications.

However his main thrust was on innovations in nuclear. He said: 'innovation really stopped in this industry quite some ago, so the idea that there's some good ideas laying around is not all that surprising'. He backed the so called 'Terrapower' idea, in which a mix of fresh uranium and depleted uranium is formed into a log type tube, buried deep in the ground and 'burnt' progressively, with the fission reaction running through it from one end to the other, like a candle. So it's sometimes called a 'travelling wave reactor'. It's envisaged that it would take 60 years to burn through end to end , and that the waste products could just be left where they were, underground . Using depleted uranium/ spent fuel to breed more plutonium and run reactors essentially from some of the wastes from conventional nuclear plants , is hardly a new idea, but the travelling wave idea is new and untried.

What Gates now wants to see is a lot of supercomputer modelling to test if it will work. He is obviously keen. If 'Instead of burning a part of uranium, the one percent, which is the U235, we decided, let's burn the 99 percent, the U238' we could "power the U.S. for hundreds of years". And there's more: "simply by filtering sea water in an inexpensive process, you'd have enough fuel for the entire lifetime of the rest of the planet". For more on the Terrapower idea see its UCB originators' website.

This says that you might need to add in some plutonium and/or thorium, basically to avoid the reaction fizzling out. Sounds a little crude and messy, leaving a wide range of wastes for future generations to deal with. And also quite hard to control, once started up. A rival approach to this mix of solids, mentioned briefly by Gates, uses liquids – actually a molten thorium flouride salt. For more on the Liquid Flouride Thorium reactor, see http://thoriumenergy.blogspot.com.

Gates evidently likes the solid idea, but the US government seems to be focussing mostly on (slightly) more conventional concepts in its 'Next Generation Nuclear Plant' R&D programme. The main emphasis is on an advanced High Temperature reactor with co-generation (CHP) capability, to be built at Idaho National Lab. WNN noted that 'This was originally meant to actually operate in 2010, but its priority has fluctuated'. NGNP is part of the 'Reactor Concepts RD&D' programme, which will also begin working on small modular reactor concepts with a total budget of $195m.

Although the Terrapower idea may be a little off the beaten track, it's interesting that nuclear plant designers are looking to new concepts, for example co-generation reactor systems which can be used to provide heat and well as power, possibly for industrial process heating purposes. In addition there is renewed interest in developing systems which can be used to generate hydrogen gas, either directly (by high-temperature dissociation of water), or indirectly (by electrolysis), for use as a vehicle fuel. It could be that they think that the long-term future for nuclear is not in electricity supply, but in other perhaps more lucrative and less contested markets. With wind power, and some other renewables, already looking increasingly competitive as electricity suppliers, perhaps that's not surprising.

Even in current cost terms the conservative Nuclear Energy Agency (NEA) and the International Energy Agency (IEA) have commented in their latest joint study into Projected Costs of Generating Electricity, that "nuclear, coal, gas and, where local conditions are favourable, hydro and wind, are now fairly competitive generation technologies for baseload power generation".

They add that "there is no technology that has a clear overall advantage globally or even regionally. Each one of these technologies has potentially decisive strengths and weaknesses".

They conclude that "the future is likely to see healthy competition between these different technologies, competition that will be decided according to national preferences and local comparative advantages".

It will be interesting to see how it all pans out long term, and, amongst other things, if Gates got it right. Personally, I don't fancy a Terrapower unit in my backyard! I'd much prefer the renewable energy technologies being backed by Google, in pursuance of its $4.4 trillion "Clean Energy 2030" plan, which calls for the replacement of all coal – and oil-fired electricity generation with natural gas and renewable electricity globally, including 380 GW of wind power, 250 GW of solar power and 80 GW of geothermal power. See http://knol.google.com/k/clean-energy-2030#.

For more on renewable energy developments and policies, see www.natta-renew.org.

There is enough sunshine to grow grapes for wine in Cornwall, so why not harvest solar electricity as well? Independent renewable energy generator and supplier Ecotricity is planning dozens of large grid-linked photovoltaic 'solar farms' in the South West and there are plans for 'Sun farms' in Cornwall and the Scilly Isles.

Ecotricity aims to start with a 25-acre, 5 MW solar farm, possibly near its HQ in Stroud, but by 2020 it plans to have 500 MW of PV arrays, all over the south of the country. Meanwhile Benbole Energy Farm, working with the Penzance- based Renewable Energy Cooperative, is planning a 15-acre Sun Farm near St Kew/St Mabyn in North Cornwall. It's seen as part of an eventual £40 m 20 MW network of 10 Sun Farms in Cornwall and the Scilly Isles.

Ecotricity say that solar farms would not be blight on the landscape, arguing that they would be less obtrusive than wind turbines, or rows of polytunnels used to grow fruit and vegetables. Dale Vince, the company's founder, told The Times (14/5/10): 'They won't stand more than 2 metres (6.5 ft) tall so you won't see them if you look across the landscape because they will be obscured by hedgerows. You would see them if you were standing on a hill but the visual impact is very minor compared with wind arrays.' But, he said that some might have solar panels and turbines in the same fields. 'Solar panels and wind turbines complement each other well because in summer the winds are lighter but there is more sunlight, with the opposite in winter.'

The farms will cost £15–20 m each but Ecotricity will receive index-linked income for 25 years from the feed-in tariff, which starts at 29p/kWh, and should yield a return of at least 8% a year. That's the main reason why large scale PV solar is now being seen as economically viable in the UK. But PV costs are also falling as new cells emerge and the market for them builds, so we are likely to see more in future.

The Campaign to Protect Rural England said that it would be better to place banks of solar panels on factory and warehouse roofs and above car parks. But it felt that some farms in the countryside could be acceptable, depending on the quality of the landscape.

PV solar is of course also widely touted as an option for domestic roof tops, and the 'Clean Energy Cashback' Feed In Tariff should stimulate that significantly: npower has already reported an 80% rise in PV inquiries and consultants PricewaterhouseCoopers have suggested that the rate of UK installation of solar PV panels will increase five-fold this year because of the feed-in tariff.

However, solar water heating is a much cheaper and already very widespread option in the UK. Hopefully that will get supported strongly by the governments proposed new Renewable Heat Incentive (RHI), which should come into force next April. In its RHI consultation submission YouGen, a social enterprise lobby group for self-generation, said solar heating should be given top priority. That would make a lot of sense.

The UK may not be the obvious place to develop solar, but we do get enough annual insolation to make a significant contribution to meeting heat and power needs.

For more on renewable-energy developments and policy, visit www.natta-renew.org.

In 2006 the Centre for Alternative Technology (CAT) in Wales produced a very radical 'Zero-carbon Britain' scenario, which envisaged UK fossil fuel consumption being cut down to almost zero by 2027, and renewables being powered up to meet almost 100% of UK electricity, with 50% of that from wind, supplying 474 TWh p.a., while overall energy demand was cut by a half. Although welcomed as a visionary exercise setting the outer limits of what might be conceived, as a practical proposal it was met with more or less polite disbelief from most of the energy-policy fraternity.

Four years on, things have changed. The government is now proposing that we get 32% of our electricity from renewables by 2020 – much of it from offshore wind, with up to 40 GW planned. Still a long way short of the CAT's 2006 vision for 2027, but this is now beginning to look more credible. So it will be interesting to see what the reactions are to the CAT's revised 'Zero-carbon Britain' scenario, running now to 2030, which was launched recently.

It is still very radical, but is much more convincing, in part because there is now more solid data to call on, including the UKERC's reports and David MacKay's book, which the CAT relies on heavily.

The new version's basic plan is similar to their earlier one – a massive 55% cut in energy use and massive reliance on renewable electricity, from offshore wind especially, which, as before, supplies much of the transport energy (via overnight battery charging of electric cars) and heating demand (via heat pumps). But the contribution envisaged from wind is now even larger – 690 TWh p.a. mostly from around 195 GW offshore. And also 75.5 TWh from wave and tidal projects, plus 50 TWh (thermal and electricity) from biomass CHP. Some biofuels are used for transport (112.6 TWh), but 65.8 TWh of renewable electricity, plus 99.8 TWh of hydrogen derived from renewable sources, is also used for transport. Demand for domestic heat is met via heat pumps (61.2 TWh of electricity delivering 148.2 TWh) and 24 TWh of solar heat, plus the biomass CHP heat input, along with 104.6 TWh of direct biomass heat – all of course being used in well insulated homes with lower heat needs.

Interestingly, the CAT does not include geological Carbon Capture and Storage (CCS), which it sees as expensive, not very efficient and still in the development stage. Instead it restricts itself to 'the proven technology of land-based Carbon Capture & Storage using natural photosynthesis' and focuses on below-ground storage in soils, above-ground in-situ storage as biomass, and long-life storage in biomass products and in engineered silos. Indeed much of the very interesting section on land use focuses on sequestration, and also on reducing carbon and other emissions from producing (and importing) food – we move away from meat (beef) and dairy (milk). That could be wise, but hard. Possibly even harder, we move away from flying and towards public transport.

On grid balancing, they say that the new offshore wind farms 'will be commissioned at dispersed locations around the country and the back-up generation consisting of biogas, biomass, hydro and imports will help to manage the remaining variability. However, all of this will need to be complemented with a large increase in the management of electricity demand. Both the supply and demand sides of the equation are malleable and both will require intensive management'.

In particular they look to demand side management i.e. rescheduling some loads via smart meters when energy is most abundant, and therefore cheaper, for the consumer. They mention electric storage radiators, heat pumps, electric vehicles, air conditioners, washing machines, fridges, freezers, dish-washers and tumble dryers. Not all on that list will be popular choices!

Another grid balancing option, in addition to pumped storage and gas turbine back-ups, is the supergrid – but while some imports of green power are envisaged from the EU (it seems about 14 TWh p.a), the CAT does not see us importing energy from Concentrated Solar Power projects in North Africa by 2030: it argues that 'security of supply is important, and depending heavily on another region of the world therefore needs to be considered carefully in geopolitical, ethical and financial terms'. And, overall. energy exports (174 TWh p.a) will heavily outweigh imports. In general, reflecting its emphasis on localisation and decentralisation, imports are seen as bad – reducing UK reliance on overseas imports of energy and also food and other consumer items, is seen as a key part in reducing our emissions.

To make it all happen the CAT looks to various changes to the support and pricing system. It backs Feed-In Tariffs, but it says 'to more effectively balance the grid, the government should implement a form of locationally differentiated pricing for new generators within distribution networks to signal the best places to build new capacity, such as at the ends of constrained distribution networks'.

That's debatable – differentiated charging by area will mean high charges for some of the largest renewable generators (e.g. in Scotland). The Scottish government has noted that, under the current system, a power station in central Scotland pays £25 m more for transmission than a similar facility in Yorkshire. The government has said that the current system reflects the cost, and raises revenue for grid improvement. Similarly, the CAT sees it as necessary for an 'interim period, until the transmission network is reinforced'. But basically it sees local micro-grids as a key to a more localised future.

It's certainly an ambitious vision, developing on the new-energy agenda that seems to be emerging in radical ways. And of course with no new nuclear.

What would it cost? The CAT says: 'Offshore wind is a central part, if not the core part, of building a green, sustainable economy in Britain. This transition and development of new industry requires investment. The peak of £30 bn in 2022 represents only 2.2% of the UK's 2008 GDP and delivers an electricity generation system, which has very low fuel costs. If we were instead to generate the proposed output of 599 TWh in 2030 from 50% coal and 50% gas, it would incur a fuel cost of approximately £13.5 bn per annum at 2008 prices. In reality these fuel costs are likely to rise far higher by 2030 and would constitute an enormous unnecessary expense to the general public'. The CAT also notes that, at a price of 4p/kWh, the proposed 159.34 TWh of net exports is worth £6.37 bn and it says that 'this annual income could really help the UK balance of payments'.

The CAT admits: 'The construction of wind turbines at the proposed rate would obviously require a considerable amount of materials.' And, based on 45% being steel and 55% concrete, that is 16.2 million tonnes of steel and 19.8 million tonnes of concrete used over twenty years, 'the embodied energy of steel and concrete for this total build would be 115 TWh'. However, the CAT says that there is a high-energy return on energy invested for wind (it quotes a 28:1 ratio), so the investment is worth it.

You can access the CAT report at www.cat.org.uk.