occasional blogger john hare
I have listened to some doomsday energy crap (gas $5.00 gallon and more forever, Japanese nuclear devastation, etc) in the last few weeks that started me thinking of alternatives again. It may be possible that one of the solar thermal generating concepts could find funding for terrestrial applications in the current mood. It may even be worth something later on out there.
A turbine engine intakes air and compresses it, heats it, and runs the expanded air through a turbine to extract the energy and run some sort of machine, often a generator. One of the solar thermal schemes has a fairly low pressure gas as a working fluid to do this job. I don’t have references for the original concept. The cool gas runs through a low tech compressor (possibly fiberglass or other in situ material) and then through an enormous solar heat collector before expanding through the (low tech of in situ materials) turbine to generate power. The exhaust heats the compressed gas in a heat exchanger before the compressed gas enters the solar collector proper. The somewhat cooled exhaust then is sub cooled in shadow or heat sink before repeating the cycle. I think the original was lunar based.
I was unable to insert a cartoon sketch of the concept this time. In raw form, the same sysem using ambient air could be used here on Earth, and could possibly generate some investment or even revenue fairly rapidly in the current energy hysteria. The heat exchanger could be clear visqueen on a roof or hillside with a dark material under it, like shingles or dark rocks. A few leaks would cost energy, but not sleep. The turbine and compressor equipment could be built from cheap fiberglass, or even wood. The idea is to build so extremely cheap that efficiency is very secondary in importance.
While this is a bit off topic, it could create some in situ class experience with other peoples’ money, and might even generate a bit of solid rocket fuel of the green folding type for the right company.