(Svar til dk.teknik.energi )
Anvend en varme-IR selektiv overflade (a la Stanford) med fx en Stirlingmotor, en elektrisk generator - og to heat-pipes:
gyroscope.com: Precision Stirling Engine:
engine will run. ..."
"Magic" heat-IR selective surface:
Stanford School of Engineering. (2014, November 26). High-tech mirror beams heat away from buildings into space. ScienceDaily:
air during the day. The multilayered material is just 1.8 microns thick, thinner than the thinnest aluminum foil. It is made of seven layers of silicon dioxide and hafnium oxide on top of a thin layer of silver. These layers are not a uniform thickness, but are instead engineered to create a new material. Its internal structure is tuned to radiate infrared rays at a frequency that lets them pass into space without warming the air near the building. ..."
Glenn