Solar Stirling Engine

A Solar Stirling engine uses solar heat as the energy source. There are several of these types of engines used in renewable power generation. I’m going to list the main ones, and provide a brief description of each.

The SunCatcher Engine, produced by Stirling Energy Systems

This solar powered Stirling engine uses a parabolic dish to focus the sun’s heat onto a receiver. A Stirling engine is placed near the focal point of a large parabolic dish, around 11 m in diameter. The dish is pointed directly at the sun using a tracking mechanism. This allows the sun’s energy to be continuously focused onto a receiver placed at the focal point. This receiver channels the heat energy into a Stirling engine which powers a generator, generating electricity.

A working gas (usually hydrogen) is contained inside the engine at high pressure. This gas is cyclically compressed and expanded in the cold space and the hot space, respectively, to produce power.

The concentrated heat energy of the sun hitting the receiver can be as much as 800 degrees Celsius!

Additional details are given below:

• Power Output — 25 kilowatts (33.5 HP)

• Speed — 1800 rpm

• Thermal efficiency — 30%

• Grid Connection — 480 V, 60 Hz

• Comments — This engine is currently not available for residential applications (homeowners). It’s only available for large utility-scale installations.

9 kW Stirling Engine, produced by Cleanergy Industries

This solar Stirling engine is very similar to the SunCatcher. The main difference is in size. The solar dish for this engine is 8.5 m in diameter, and the concentrated heat energy of the sun hitting the receiver is around 650 degrees Celsius. The working gas is Helium or Hydrogen.

Additional details are given below:

• Power Output — 9 kilowatts (12 HP)

• Speed — 1500 rpm

• Thermal efficiency — around 20%

• Grid Connection — 400 V, 50 Hz

• Comments — This engine can also be equipped for combined heat and power (92-96% total efficiency), with natural gas or biogas as fuel (with resulting electrical efficiency of 25%). This engine is currently not available for residential applications (homeowners). It’s only available for large utility-scale installations.

For additional information see http://www.cleanergyindustries.com

Infinia Solar System, produced by Infinia Corporation

This solar Stirling engine also uses a solar dish to concentrate the sun’s heat for power generation. This particular engine is a Free-piston configuration, which allows a hermetic seal of the working gas inside the engine, resulting in practically no leakage of working gas, and no lubrication requirements. Very little maintenance is necessary. The solar dish for this engine is 4 m in diameter. The working gas is Helium.

Additional details are given below:

• Power Output — 3 kilowatts (4 HP)

• Thermal efficiency — 24% peak

• Grid Connection — 240 V, 50 or 60 Hz

• Comments — This engine is currently not available for residential applications (homeowners). It’s only available for large utility-scale installations.

For additional information see http://www.infiniacorp.com