Solarwave

Bagenalstown Business Park

County Carlow

Ireland

The Solar Dish Engine holds out the prospect of allowing solar energy to take the place of Hydro and Fossil Fuel generation with the least amount of re-engineering and grid upgrading.

The Solar dish traps sunlight by concentrating it by means of a parabolic reflector and using the heat that the focussed energy produces to generate electricity. The most usual means for this electrical conversion is by use of the Stirling Engine, a generic term for a type of reciprocating engine that does not require chemical fuel for ignition. The engine converts raw heat energy into motion. The motion is then utilised to power an electricity generator. All that is required is a medium to transport the heat to the engine. This can be in the form of a helium or hydrogen vector, a circulating gas that simply picks up the heat at the collector and transfers it to the engine as required.

Close up of the Power Conversion Unit (PCU), a Stirling engine with heat transfer interface. Located at the focal point of the parabolic array, as circled in the main picture above. Picture courtesy of Stirling Energy Systems inc.

Stirlng engines are very efficient. They are also very quiet in operation. This technology has strong potential to bring reliable electrical power to remote or underdeveloped areas that are not served by a grid.

As usual, nothing comes entirely for free. Large scale solar systems generally need to have the ability to track the sun as it moves relatively across the sky during an earth day. This requires motors and computerised positioning systems for successful operation. These, in turn, require the use of energy. However, the inclusion of high efficiency engines, such as the Stirling engine, and good design can mitigate these effects.