US and South Africa race to deliver world's largest solar farms

The US and South Africa this week have each moved a step closer to building two giant new solar farms, both of which will lay a claim to being the world's largest and could serve to establish the countries as solar technology hubs.

The US looks set to secure the title first after the Department of the Interior yesterday gave final approval to a proposed 1GW solar project planned for Blythe, California.

The giant project is backed by German solar firm Solar Millennium and is expected to cover 7,000 acres, ultimately providing energy for up to 750,000 homes.

US secretary of the interior Ken Salazar hailed the project as a "major milestone" in the development of America's renewable energy economy, adding that it provided further evidence that the US government will support the emerging low-carbon sector.

The company is still in talks with the US Department of Energy in an attempt to secure $1.9bn (£1.19m) in federal loan guarantees, but it said that it was confident that the project would begin before the end of the year.

The project, which will use giant parabolic troughs to concentrate the sun's heat on a fluid tube that will be used to create steam that drives a turbine, will be rolled out in four phases with each unit generating up to 250MW of power.

The planning approval represents the latest in a series of green lights for large solar farms in southern California. For example, construction is scheduled to begin on Wednesday at another recently approved major project, Brightsource's high-profile Ivanpah solar farm.

However, Blythe's status as the world's largest solar farm could prove short lived if ambitious plans to be unveiled in South Africa later this week are realised.

According to reports in the Guardian, the country's government will this week unveil plans for a £18.4bn project that would ultimately generate up to 5GW of electricity, meeting up to 10 per cent of South Africa's current energy needs.

Up to 200 potential investors are expected top meet this week to hear about the plans, which would see a string of solar plants cover a 9,000 hectare area in the Northern Cape, a region with some of the highest levels of solar energy in the world.

The plan will be presented by US engineering giant Fluor and is backed by a viability study from the Clinton Climate Initiative. Experts predicted that the work on the initial 1GW facility could get under way as early as 2012 with the entire solar farm completed by 2020.

Jonathan de Vries, the project manager, told the Guardian that the development would represent the largest solar park in the world, adding that the Northern Cape provided the perfect location for the project. "It hardly ever rains, it hardly has clouds," he said. "It's even better than the Sahara desert because it doesn't have sandstorms."

In related news, another ambitious African renewable energy project delivered an encouraging update this week when Kenya's government-backed Geothermal Development Company (GDC) announced that it has secured 40 per cent of the money it requires to build a pioneering 2GW geothermal power plant in the Rift Valley.

GDC managing director Silas Simiyu told news agency Reuters that the company had already raised $400m, and was moving forward with plans to deliver 500MW of geothermal energy by the end of 2012 and 1GW by 2015.

"There is a lot of excitement in terms of the support that we are getting from outside," he said. "When we came up with our business plan and we talked of 5,000MW by 2030, it was thought that the plan was very ambitious."