Several CSP plants already operate around the world, mainly in the US and Spain. They use synthetic oils to capture the Sun’s energy in the form of heat, by using mirrors that beam sunlight onto a pipe where pressurised oil heats up to around 390°C. A heat exchanger is then used to boil water and run a conventional steam turbine cycle. Older CSP plants can only operate at daytime – when direct sunlight is available -, an issue that has been dealt with in recent years by introducing heat storage, in the form of molten salts. Newer CSP plants, as the many under construction in Spain, use molten salts storage to extend the plants’ daily operating hours. Archimede is the first plant in the world to use molten salts not just to store heat but also to collect it from the sun in the first place.

Image: Archimede Solar Energy

This is a competitive advantage, for a variety of reasons. Molten salts can operate at higher temperatures than oils (up to 550°C instead of 390°C), therefore increasing efficiency and power output of a plant. With the higher-temperature heat storage allowed by the direct use of salts, the plant can also extend its operating hours well further than an oil-operated CSP plant with molten salt storage, thus working 24 hours a day for several days in the absence of sun or during rainy days. This feature also enables a simplified plant design, as it avoids the need for oil-to-salts heat exchangers, and eliminates the safety and environmental concerns related to the use of oils (molten salts are cheap, non-toxic common fertilizers and do not catch fire, as opposed to synthetic oils currently used in CSP plants around the World). Last but not least, the higher temperatures reached by the molten salts enable the use of steam turbines at the standard pressure/temperature parameters as used in most common gas-cycle fossil power plants. This means that conventional power plants can be integrated – or, in perspective, replaced – with this technology without expensive retrofits to the existing assets.

Carlo Rubbia

So why hasn’t this technology come before? There are both political and technical issues behind this. Let’s start with politics. The concept dates back to 2001, when Italian nuclear physicist and Nobel prize winner Carlo Rubbia, ENEA’s President at the time, first started Research & Development on molten salt technology in Italy. Rubbia has been a preminent CSP advocate for a long time, and was forced to leave ENEA in 2005 after strong disagreements with the Italian Government and its lack of convincing R&D policies. He then moved to CIEMAT, the Spanish equivalent of ENEA. Under his guidance, Spain has now become world leader in the CSP industry. Luckily for the Italian industry, the Archimede project was not abandoned and ENEA continued its development till completion.

There are also various technical reasons that have prevented an earlier development of this new technology. Salts tend to solidify at temperatures around 220°C, which is a serious issue for the continuous operation of a plant. ENEA and Archimede Solar Energy, a private company focusing on receiver pipes,  developed several patents in order to improve the pipes’ ability to absorbe heat, and the parabolic mirrors’ reflectivity, therefore maximising the heat transfer to the fluid carrier. The result of these and several other technological improvements is a top-notch world’s first power plant with a price tag of around 60 million euros. It’s a hefty price for a 5 MW power plant, even compared to other CSP plants, but there is overwhelming scope for a massive roll-out of this new technology at utility scale in sunny regions like Northern Africa, the Middle East, Australia, the US.

The Italian CSP association ANEST claims Italy could host 3-5,000 MW of CSP plants by 2020, with huge benefits also in terms of jobs creation and industrial know-how. A lot more can be achieved in the sun belt south of the Mediterranean Sea, and in the Middle East. If the roll out of solar photovoltaics in Italy is to offer any guidance (second largest market in the World in 2009), exciting times are ahead for Concentrating Solar Power.

By Carlo Ombello. Carlo’s web site is at www.opportunityenergy.org

The only other company currently making forgings of sufficient size for an international market, Japan Steel Works, has recently tripled its capacity to make 10 pressure vessels a year. But last year 11 new nuclear power stations were begun around the world and the pace is accelerating. 55 reactors were in full planning at the end of 2009 and in the US over 30 licence applications are under active discussion.

Without the new investment by Sheffield Forgemasters, the waiting list for pressure vessels means that EDF’s plan to build at least one nuclear power plant in the UK by 2017 will be unattainable. The waiting list for pressure vessels is too long. Korean and other companies, including two in China, intend to enter the business of making large forgings. But the work necessary to ensure the steel is made to the right quality is bound to take several years. Any failure of the reactor core would be catastrophic and customers will be wary about buying from a company without sufficient experience. Sheffield Forgemasters was one of the small number of businesses around the world that might have increased the speed of rollout of new nuclear. Forgemasters might have been the central company in a nuclear renaissance in the UK.

What is the new government’s logic? Does it really believe that Labour’s proposed Forgemasters loan was a crude attempt to buy votes in Sheffield constituencies at the May election and therefore was commercially unjustified? Or does it think that the loan was incompatible with its stated commitment to making nuclear stand on its financial feet? In either event, with one move it has delayed any UK nuclear construction by at least two or three years.

On the other hand, it may just have hoped that Westinghouse, the maker of the competitor to the Areva EPR power plant, would step up to replace the state loan with private money. Westinghouse owns a stake in Forgemasters and desperately needs an alternative supply of reactor forgings to reduce its dependence on Japan Steel Works. This looks a risky gamble. EDF is furthest ahead with UK plans for new nuclear reactors but is committed to the Areva design for the UK, not the slightly smaller Westinghouse equivalent. The idea that EDF will commit to buying its pressure vessels from Forgemasters if it is principally backed by its main competitor looks unlikely.

Whether one wants nuclear power or not, this decision looks like ill thought through and dangerously destructive to the already weakening confidence in the prospects for construction in the UK.  £80m is not a tiny amount, but in the context of the need to spend over £10bn a year for the next generation on new power stations it is small change.

Myles Allen wants the Greens to revert to being a party solely concerned with the environment. He says that by offering a full slate of policies we are weakening our appeal to people who those want a focus on climate change and other urgent ecological issues. He says that by linking our policies on the environment to wider ambitions for improving Britain, we are diluting our appeal to our natural supporters. In fact he thinks that our environmental concerns are little more than a cloak to disguise our ambitions for more equitable Britain. We aren’t really interested in arresting climate change, he seems to say. Our secret desire is to build a fairer society.

At the European elections in June of last year, Oxford voters like Myles cast more votes for the Green Party than any other political grouping. In any reasonably fair political system one of Oxford’s two MPs would be wearing a Green rosette on May 7^th. Why do so many of his neighbours support the party when Myles himself think that our approach is muddy and confused because it aims both at climate change objectives and at broader social goals? In my experience of talking to local voters, most of them see the strongest of connections between environmental and other political issues. Local Green councillors have shown that action on climate change is wholly compatible with improving the services offered by councils and public services.  For example, improving public transport is good for the environment and good for communities. Getting recycling rates up reduces methane emissions as well as reducing the need for new landfill sites. Investing in municipally-owned wind farms is profitable and will reduce council tax for Oxford voters. Improving access to locally grown food reduces energy consumption and helps bind communities together.

Dr Allen’s research group continues to warn us that fossil fuel consumption must eventually fall if we are to avert accelerating climate change. Partly as result of his work, most people know that economic growth based on the increasing use of fossil fuels is extremely unlikely to be possible or desirable.  So they back the Green New Deal, an attempt to rebuild Britain’s manufacturing, agricultural, forestry and building industries around low carbon alternatives to our wasteful use of coal, gas and oil. Our focus on clean technology is an attempt to use British engineering skills to decrease pollution levels and diminish the harm we impose on the environment. This is neither pointless from a climate change standpoint nor from the need to improve employment prospects for young Britons.

Right at the heart of the Green campaign is the slogan that Dr Allen seems most to dislike ‘Fair is worth fighting for’. Briefly, let me say why I think fairness is important. The UK faces some major challenges, of which reducing emissions is one of the most urgent and important. So far, Britain has transparently failed to achieve progress on this and many other issues. The Green hypothesis is that this failure partly derives from our unequal and fractured society. How can any political party build consensus on the need for large scale sacrifices or for difficult choices if some groups in society are so well off as to be insulated from the cost? Societies that put fairness at the heart of their policy-making, such as the Nordic countries or even less well-off states like Costa Rica, find it easier to build cohesion and a shared commitment to undertaking painful changes. Those who want action on climate change should vote Green both because of our commitment to taking action on emissions and because we are more likely to build the sense of fairness and shared purpose that will make it possible to achieve those reductions.

Much to my personal regret, Myles will not be marking his cross against the Greens in three weeks time. So who will get his vote in Oxford West and Abingdon? UKIP, the people who think that climate change is fabrication? Labour, which wants to build a third runway at Heathrow, and has expanded road building? And having been in power for thirteen years has pretty much the worst record on renewable energy of all European countries? The Conservatives, whose new prospective MPs are said to be agnostic on climate change and who have opposed almost every onshore wind farm?  Or finally, the LibDems, who have just proposed reducing fuel duties for transport and whose councillors blocked the nearest wind farm to Oxford for ten years while backing new local road schemes? Dr Allen wrote last year that ‘emission reductions are urgently needed to avoid dangerous climate change’. Who else does he trust more than the Greens to achieve these reductions?