The World’s Largest Solar Farm Will Use Solar-Thermal Technology

Concentrated Solar Power Plant - Wikipedia
IMAGE: Wikipedia/Concentrated solar power

SolarReserve has finalized plans for a massive, 2-gigawatt solar power plant in Nevada, hoping to sell its power to California, which is scheduled to source half its power from renewable energy sources beginning 2030. Spread over 15,000 acres, its power output will be the equivalent of the Hoover Dam or two nuclear power plants. It is estimated to cost $5 billion and instead of using photovoltaic cells, it will use solar-thermal technology (concentrated solar power). It will also have storage capabilities so that it can keep feeding energy into the grid 24 hours a day instead of overloading it during daytime.

What is concentrated solar power or CSP?

Mirrors reflect sunlight onto towers that are topped with molten salt. The heat causes the temperature to rise to 1000 °F or 538 °C and remain that way for ten hours. Steam is subsequently generated, which is used to run generators.

This ambitious project would have ten towers. The biggest existing concentrated solar power plant, in comparison, has only three towers and generates 392 megawatts in the Mojave Desert (Ivanpah Solar Power Facility run by BrightSource Energy). Solar Reserve’s own experience with solar-thermal technology is much more limited. Its Crescent Dunes project in the Nevada desert, based on the same technology, generates only 110 megawatts.

Solar-thermal technology is more expensive than photovoltaic (PV) cells, but Solar Reserve CEO Kevin Smith is confident of producing power for cheaper. He estimates the cost per kilowatt of energy to be 12.5 cents per kilowatt-hour (similar to the cost of production with PV cells), which will subsequently drop to 7.5 cents. The project, codenamed ‘Sandstone’, is scheduled to be completed in seven years, built over stages; and break even in three years.

Construction is slated to begin in 2-3 years, and once it does, Smith expects 3,000 new jobs to be created. The Crescent Dunes project, which went online earlier this year, created 600 jobs during its construction.

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Do the numbers add up?

Nathan Serota, a New Energy analyst, is not convinced. He thinks that it will not be possible to deliver the price at a competitive rate when it is completed – and he may have a point. The cost of generating power from photovoltaic cells is decreasing (it costs nothing to produce energy from the sun, and the only costs involved are the PV cells themselves). It is 12.5 cents per kilowatt- hour now, the price point Smith hopes to achieve in ten years. By that time, the cost of solar energy production will have dropped, making Smith’s power more expensive. The only advantage that Smith has is that his concentrated solar power plant can feed energy into the grid round the clock (thanks to massive storage capabilities), and this might attract utility companies who could thus save on infrastructure spending.

The 7.5 cents-per-kilowatt-hour price still wouldn’t be enough – that is the rate at which natural gas combined cycle power plants produce energy today.

For the U.S. homeowner, it is cheaper to install PV cells and generate energy for his/her needs. With subsidies, it costs $17,000 to install a solar system. This is the national average, but it is less than $10,000 in many states. Over a 20 year-period (this includes the 10 years it takes to pay for itself), the total savings are estimated at $20,000. comment