Google invests $10.25 million in geothermal technology

Google's philanthropic arm, Google.org, is investing $10.25 million in two companies working on a new way to tap into the heat beneath the earth's surface.

The companies are AltaRock Energy, which gets $6.25 million, and Porter Drilling, which gets $4 million. Additionally, the Geothermal Laboratory at Southern Methodist University, which is working on locating geothermal sources in North America, will receive a grant of about $490,000.

The money comes from Google's RE<C initiative, which seeks to develop renewable energy sources that are cheaper than electricity produced from coal.

Unlike the traditional geothermal systems that have been providing power for more than a century, the technology that Google is investing in does not require naturally occurring geysers or hot springs. An "enhanced geothermal system" works by injecting water into hot rocks deep in the earth's crust, and then bringing the steam back up to power turbines.

According to the US Department of Energy, EGS could increase the potential of geothermal energy by a factor of 40.

Here's a video from Google.org explaining how it works:

The process is not without its potential pitfalls. In 2006, Reuters reported that Swiss engineers halted an enhanced geothermal experiment after it triggered an earthquake in the city of Basel. The quake, which registered 3.4 on the Richter scale, caused no injuries or serious damage.Forbes reports that developing such systems will take some time.

[T]here is not a single megawatt of EGS-produced power on line yet, and, at best, it will be quite a while before it becomes a significant energy source. It takes years to fully develop a site, from surveying the geology, drilling test wells, receiving permits, drilling working wells and building generators. And it takes capital. Each well can cost $5 million to drill, double the cost of an oil or gas well, because the holes need to be twice as deep, 15,000 feet or more, and sites need at least four wells. Geologists and engineers have a lot to learn about the rock formations they will encounter.

Despite the costs, geothermal energy is attractive to many utilities, because, unlike wind and solar power, it can provide a consistent, "baseload" power.

Google's announcement came out the same day as a report from the Earth Policy Institute that says that geothermal energy – the traditional, non-enhanced kind – is poised to "move rapidly from marginal to mainstream." The report notes that current installed geothermal capacity now produces enough electricity for 60 million people. According to the report, traditional geothermal resources could provide electricity to meet the needs of 750 million people worldwide.