Background

The 354 MWe of parabolic trough plants (SEGS I — IX) installed in the Californian Mojave Desert have been one of the most successful showcase for solar projects worldwide in the last decades. Since nearly 20 years thousands of parabolic trough collectors — with a total reflecting surface of more than 2.000.000 m2 — are tracking on a day-to-day basis the sun and focus precisely the sunbeams onto the absorber tube. The extensive twenty-year operation records demonstrate impressively the reliability and maturity of the parabolic trough technology.

After the oil crisis in the 70’s, the Californian government established favourable legal and economic frameworks with tax incentives and long-term feed-in tariffs guaranteed by the government to support the market introduction of the concentrating solar power technologies. These investment-friendly environments together with a mature, economic and emission-free technology have been the main pillars for the success story of the SEGS plants.

After the withdrawal of the “solar” framework in the U. S. at the end of the 80’s, it needed nearly ten years that another industrialized country in the sunbelt of the world established similar favourable conditions for the erection and operation of solar thermal power plants. With the passing of the Royal Decree 2818/1998 — which encourages and outlines the conditions to meet Spanish objectives in the reduction of global greenhouse gas emissions — Spain provided the legal foundation for the development of the first parabolic trough power plant in Europe. The Solar Millennium Group with its Spanish subsidiaries started immediately after the publication of the new framework with the project development of
parabolic trough power plants in Spain. Extensive site studies in Southern Spain identified promising locations for the implementation of solar thermal power plants with parabolic trough technology in the region of Andalusia, Castilla-La Mancha, Extremadura and Murcia. After several modifications and revisions of the feed-in tariff, the Spanish government finally established with publication of Royal Decree 436 in March 2004 economic conditions and tariff stability which will attract equity and debt investors with risk- adjusted rate of returns on their investment. Royal Decree 436 might be the break-through for the commercial market introduction of this technology and the start in a new solar millennium.