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Success stories Published on 26-Feb-2004

Title Here comes the sun

Solar power is a vast and underused resource which could, if harnessed effectively, go a long way to meeting the world’s energy requirements. Technological and economic factors have limited its impact to date, however. Teams from Europe and Israel have been co-operating in a project that has made significant progress towards overcoming these problems. They have designed a very large solar parabolic trough collector, and produced and tested a prototype. They are confident that the commercial uptake of their new designs will be substantial. Such success still lies in the future, but the early signs are very encouraging.

Sun and chimneys
‘Solar power is the energy source of the future, as it always has been,’ says the joke. Its progress has been dogged by technological shortcomings and a lack of commitment on the part of public authorities to move away from cheap, convenient fossil fuel energy sources. But in a world ever more aware of its finite natural resources, attitudes are slowly beginning to change.

In 1998, in an attempt to reduce the country’s dependency on fossil fuels – and to achieve reductions of greenhouse gas emission agreed in the Kyoto Protocol – the Spanish government decided to pay a premium for electricity produced from sustainable sources powered by solar energy. The premium of €0.12 per kilowatt/hour prompted some companies to take a long, hard look at the possibilities of solar power. Among them was Abengoa, and in particular its subsidiaries Inabensa and Solúcar, both leaders in the solar energy field.

Looking in the mirror
“This premium presented us with a real opportunity,” says Rafael Osuna González-Aguilar, project manager of the Inabensa Solar Energy department. “We assessed all the systems available for producing power from solar sources, particularly those based on parabolic mirror capturing techniques. What we found was hardly encouraging. Even the best technologies were uneconomic, even with the premium. Manufacturing, maintenance and running costs were simply much too high.” The financial gap led Inabensa and partners from across Europe to develop a proposal for an EU-funded RTD project, whose success led to the ‘Eurotrough I’ initiative. “Our fundamental goal was to reduce costs, and we did achieve considerable reductions,” recalls Osuna. “But even then, the systems were still too expensive.”

Nevertheless, the results were positive enough for Inabensa and some of the other Eurotrough I partners, together with two new participants from Europe and Israel, to embark on Eurotrough II in order to push the development of solar power still further. “We set out to design and build collector systems that were much cheaper to manufacture,” explains Osuna. “Each partner had specific tasks to perform within this overall objective. Inabensa coordinated the project, contributed to the design and manufacturing techniques required to produce the collectors, and manufactured and set up the prototype. SBP, a German engineering company, made a major contribution to the design of the new collector, and assisted in the development of new manufacturing processes, based on experience gained in Eurotrough I. Flabeg made specially designed mirrors and participated in trials at pilot plants in Spain and Mexico, working closely with Solúcar and Iberdrola, a Spanish utility company. The Deutsches Zentrum für Luft- und Raumfahrt and CIEMAT were in charge of testing the prototype, while SOLEL, the only company in the world to manufacture the collector tubes required by the Eurotrough design, modified their systems to suit our exact needs.”

The results of the collaboration, with parabolic mirrors and collector tubes spanning lengths of over a hundred metres, are extremely impressive, with power generation capacity for the first time being measured in MW, rather than kW.

Close and closer still
Is Osuna satisfied with the consortium’s achievements? “We made a good deal of progress,” he says. “But of course there is still some way to go. The systems still cannot compete directly with fossil fuel powered electricity generation. We will continue to work on cost reduction. In the meantime, we are trying to encourage the Spanish government to increase the sustainable energy premium to the point where the technology becomes viable. Meanwhile, the environmental agency of the World Bank, which is eager to promote the use of solar power generation, is awarding funding support for the construction of three plants of 50 megawatts each – in Mexico, India and North Africa. This represents a further opportunity to install the Eurotrough collector.”

The partners are only too aware that they cannot rely solely on governmental and international agency support to promote the technology. Several of them are still working on the cost reduction aspects while, at the same time, promoting the system worldwide. “We have not yet made a real commercial breakthrough,” concedes Osuna. “We must take Eurotrough to the point where the cost accountants as well as the engineers are happy with it. When we get there, we will have a major success on our hands. We are making progress, but we realise that it could take some time, and remain committed to the long-term game. Effectively, the challenge is to change completely people’s attitudes to sustainable energy resources.”

  • Title
    Extension, test and qualification of a full scale loop of eurotrough collectors with direct steam generation (Eurotrough II)
  • Reference
  • Programme
    FP5: Energy, Environment and Sustainable Development
  • Contact
    Mr. Rafael Osuna González-Aguilar
    Fax +34 95 493 7008
  • Partners
    Inabensa, Spain
    Solúcar, Spain
    CIEMAT, Spain
    Deutsches Zentrum für Luft- und Raumfahrt, Germany
    Flabeg Solar International, Germany
    Iberdrola, Spain
    Schlaich Bergermann und Partner, Germany
    Solel Solar Systems, Israel