Cheaper, Simpler Solar Thermal Using Stirling Engines
A recent study found that solar thermal power could provide 25 percent of the world's electricity needs if investments increased and the technology was put in place. That makes the new design by Stirling Energy Systems for harvesting that energy particularly compelling.
The company claims it has come up with a new solar thermal system that is simpler than other versions of the technology and will make the energy cheaper. The company plans to start building large solar power plants using this design within the next year.
The system called the SunCatcher consists of a large, mirrored dish that concentrates sunlight onto a Stirling engine. The temperature difference between the hot and cool sides of the engine drives the pistons, which generate electricity. Each unit can produce 25 kW of electricity and the company plans on using about 12,000 units in its first project in Southern California for a capacity of 300 MW.
The company expects the electricity to cost about 12 - 15 cents per kWh, which is competitive with electricity prices during peak hours in some markets.
This technology has the benefit of using less water than solar thermal plants that collect heat over a large area to drive turbines in a central facility. The turbines use a lot of water to keep them cool, but Stirling's design doesn't require water, making it ideal for desert climates where solar thermal is well-suited.
Another advantage to their system is that it's easier to increase the amount of energy generated by just adding more units instead of having to make a central facility bigger. The downside to this is that there's no central storage for the energy that is produced, so right now the system can only make electricity during daylight hours where other solar thermal plants can continue supplying energy overnight.
The storage issue will definitely have to be solved for this new technology to really take hold, but if they can do that, the advantages make this new system really exciting.