Google has said that it intends to generate more of its data center power using renewables. But which technologies provide the most promise to generate power cheaper than coal and in the "utility-scale" volume required to operate a data center? Wind? Hydro? Thermal solar?
On July 24 Google "green energy czar" Bill Weihl gave a detailed presentation on the company's computing infrastructure and its energy efficiency. For the first 40 minutes of the one-hour presentation, Weihl talks about Google's server infrastructure and efficiency initiatives at the server and processor level.
Weihl then spends about 15 minutes discussing the various renewable energy options and their current cost profiles. This is perhaps the most interesting segment given Google's desire to use more green power in its data center operations. The challenge, as Weihl acknowledges, is that it's hard to find power that is both renewable and cheap.
"From a cost point of view, renewables can't compete at all," says Weihl, who was previously the CTO at Akamai. At about the 48 minute mark, Weihl discusses a slide that outlines the comparative cost of various renewable energy sources, including wind, nuclear, geothermal, thermal solar and photovoltaic solar (using solar panels to generate power). Weihl notes that photovoltaic solar energy currently costs about 25 to 30 cents a kilowatt, which is "completely out of range" with all other power sources.
He notes that Google is investing in efforts to generate renewable energy that is cheaper than coal (we've noted its investments in wind, thermal solar and geothermal energy). He also mentions that Google has secret research projects around renewable energy. Weihl provides no details, but this clearly would include the recent patent of an ocean-based data center concept. The full video of Weihl's 58-minute presentation is available below.