German researchers have developed a new way of storing heat in a thermal solar power plant. This DLR press release explains the concept.
The idea is to replace molten salts used now with ceramic particles of about one millimeter size. These are placed in a rotating drum at the top of a solar tower. There they can be heated to any temperature up to 1,000 degrees Celsius, depending on the speed of the drum rotation.
One advantage over molten salt is that electricity generation with a steam turbine is more efficient at temperatures between 600 and 800 degrees, which can’t be done with molten salts. Another advantage is cost. The system will be cheaper than existing salt-based concepts.
The heated particles can also easily be transported to some factory site that needs process heat. And since the heat can be regulated by changing the rotation speed, it can be delivered exactly as needed.
The technology has been successfully tested in a small 10 kW prototype. The plan is to scale this up to larger capacities in the next couple of years.
One advantage of generating solar energy in the Sahara instead of Germany is that thermal solar requires more solar resources than Germany has. That makes any advances in thermal solar energy most welcome news for the Desertec project.