| Combined Cooling Heat and Power Plants for Trigeneration (CCHP) | 
| Decentralised heat and power plants fired by biogas, vegetable oil, natural 
gas, or fuel oil | 
|  Solar Thermal Energy | 
| 
	economic flat plate collectorsvacuum tube collectorsparabolic through collectors | 
| Geothermy, District Heat or Waste Heat | 
| 
	geothermal energy from deep layers of the earthdistrict heat from centralised combined heat and power plantswaste heat from industrial processes | 
| Negligible energy costs | 
| 
	Low driving temperatures below +100 °C |