Google steps up efforts to develop renewables that are "cheaper than coal"

Google has revealed further details of its plans to establish the company as a major player in the clean energy field, underlining its commitment to the development of concentrated solar thermal, enhanced geothermal and, most intriguingly, high-altitude wind systems.

In an interview with the New York Times, the company's Green Energy Czar Bill Weihl said the company was fully committed to accelerating the development of renewable energy technologies that can prove more cost-effective than coal power, as a means of both curbing carbon emissions and trimming its own giant energy bill.

"We use energy and we care about the cost of that, we care about the environmental impact of it, and we care about the reliability of it," he said.

Weihl highlighted the company's existing investments in concentrated solar thermal systems through eSolar and BrightSource, and revealed that Google is working on technologies that could improve the performance of their solar thermal plants.

"We're doing some internal R&D work on the mirrors — things that eSolar and BrightSource aren't looking at and really shouldn't be looking at: they don't need to take the risks to explore these kinds of designs and materials," he said, adding that Google researchers were also looking at technologies that could adapt the receiver that collects the heat that is generated by solar thermal systems in order to allow it to operate at higher temperatures.

Weihl also referenced the company's backing for enhanced geothermal energy developers AltaRock Energy and Potter Drilling, and intriguingly highlighted one of Google's lower-profile renewable energy investments - its backing for high-altitude wind energy firm Makani Power.

Since 2006, Google has pumped at least $15m into the company, which specialises in using high-altitude kites to generate energy, and Weihl told the New York Times that, in addition to the investment, Google was working on wind turbine technology that could bring the cost of renewable energy below that of coal.

"We've been looking at some ideas that would let you go up and build a turbine at 200 metres at very little extra cost," he said. "If that pans out, it would be a way to knock 20 or 30 per cent off the cost of wind, and wind is pretty close to the cost of coal today."