A group of 12 large European companies, nine of them German, on Monday signed up to an ambitious transcontinental renewable-energy project, which proponents argue could eventually supply up to 15% of Europe's electricity requirements by 2050 and involve an investment in Africa and the Middle East of around €400-billion.

Dubbed 'Desertec', the project aims to harvest solar and wind energy from the Sahara desert, in North Africa, and transmit the power over a network of long-distance high-voltage direct current (HVDC) cables to parts of Europe.

Financial, energy and industrial heavyweights - including Munich Re, Deutsche Bank, RWE and Eon, ABB and Siemens - gave their backing to the Desertec Industrial Initiative (DII) at a launch function hosted in Munich, Germany. The other participants included Abengoa Solar, Cevital, the HSH Nordbank, MAN Solar Millennium, M+W Zander and Schott Solar.

The DII planned to draft business plans and associated financing concepts over the next three years, as well as initiate industrial preparations for building a large number of networked solar thermal power plants to be distributed throughout the Middle East and North Africa region.

The concept has been discussed and debated for about three decades, but speaking at a media briefing in Johannesburg in early July, Siemens managing board member Dr Siegfried Russwurm asserted that the solar-, wind- and transmission-technology elements necessary to develop the project were now available.

The project would involve the production of electricity in solar thermal, or concentrating solar (CSP), plants in the desert regions of North Africa, as well as at wind farms in Africa and off the coasts of Europe.

CSP facilities use mirrors to focus the sun's rays on to a receiver containing a heat transfer fluid, and the heat energy is used to produce steam that drives a turbine. Energy can be stored in the fluid allowing the plants to operate more or less as base-load facilities, if so configured.

Under Desertec, hundreds of such CSP plants, as well as wind farms, would be integrated through transmission systems and HVDC transmission cables under the Mediterranean Sea, to power parts of Europe, the Middle East and North Africa.

Proponents argued that the latent solar potential in the world's desert regions would be sufficient to generate power for more than 4 800 h/y. They add that these regions receive more energy in six hours than can be consumed in one year.

However, Russwurm cautioned that it would be premature to put figures to the potential order flow that could arise in favour of Siemens, noting that major feasibility investigations were still required. Nevertheless, he described the project as "courageous" and likened it in significance and scale to the laying of the first transcontinental telecommunications lines.

Detractors, however, see the project as an expensive flight of fancy, while arms-length supporters warn that the proposed time horizons seemed overly ambitious, especially given the amount of technical work still required, as well as significant legal and financial challenges.

Nevertheless, the green-energy project has high-level political backing, particularly in Europe where stiff greenhouse gas reduction targets have been set.

Further, countries such as Germany see the development as providing a potential new export industry for an embattled manufacturing sector, currently rocked by recession.