The Crescent Dunes Solar Energy Project covers 1,670 acres of Nevada desert. When it officially opened in February this year, the massive plant was the world’s first solar facility to use molten salt as both a heat transfer fluid and a way to store thermal energy even when the sun goes down or the weather is bad. SolarReserve poured $1 billion into building the plant as a completely solar, totally sustainable facility, with no natural gas or fossil fuels required.
It only takes one glance at the Las Vegas strip to realize why power usage doesn’t go down when the sun sets in Nevada. Solar power is becoming more and more affordable as technology to make the resource available improves, but surplus energy storage has been a big obstacle in order to guarantee power even at night. The Crescent Dunes plant relies on more than 10,000 sun-tracking mirrors. These mirrors store the solar energy in a pit of salt that is heated to about 1,000 degrees Fahrenheit. In order to provide power to the grid any time of day or night, the heat stored in the molten salt is used to turn water into steam that powers energy generators.
10,347 tracking mirrors (heliostats), each about the size of a billboard, focus the sun’s energy onto the receiver.
“Whether it’s in the daytime or the nighttime, it provides base-load stable power. If you get a bit of cloud cover that goes across at three o’clock in the afternoon, we’re always drawing out of storage, so we continue to operate at 110 megawatts. We don’t miss a beat, and the utility doesn’t see any fluctuations in the power output over the day,” said Kevin Smith, CEO of SolarReserve.In the near future, SolarReserve has its sights set on a series of similar solar plants in China. Their first one-gigawatt plant in China will be ten times the size of Nevada’s Crescent Dunes facility, and SolarReserve plans to complete another ten Chinese plants on top of that by the year 2020. Considering the incredible population growth and dire environmental issues in China, solar energy is poised to make a big difference to resource consumption.