The Ivanpah solar energy project, currently the world’s largest solar thermal power plant, has been switched on in the Mojave Desert to the northwest of Los Angeles. The massive solar thermal plant was developed by BrightSource Energy which, as we reported previously, is partly backed by investments from Google and Goldman Sachs. The plant, operated by NRG Solar, is able to produce 377 megawatts of power. That’s enough power to supply about 140,000 homes.
The solar thermal plant is constructed with 347,000 heliostats (mirrors) spread around 3 central towers containing boilers. The heliostats focus the sun’s rays on the top of the towers. This creates heat in the tower boilers, which produce steam to turn turbines to create electricity.
One issue with a solar thermal plants like this, as opposed to a solar panel power plants, is that they use a lot of water, and California is currently experiencing a severe drought. Solar thermal power plants may have to use different cooling processes to avoid using so much water. Dry cooling is something that BrightSource is working on. This could cut water consumption by 90% but is more expensive and limits power production somewhat. Even so, the company has noted that it is the responsible decision to make, and still makes the project economically-viable. The added cost will still pay off in the long run.