SHPEGS — DIY Solar/Geothermal Electricity

rohar writes "SHPEGS is an open design not-for-profit project to design and prototype a base-load renewable electrical generation system suitable for moderate climates and built from common materials. The design centers around creating a local geothermal source with an efficient solar thermal water heater system and can be scaled from single residence to mega-scale. The heliostat system used in Europe's first solar thermal plant could be used in a scaled-down SHPEGS system with Practical Solar's small scale heliostats."

Comments

Re:Efficiency?

[mdsolar]

Thanks. I'm looking for a number though. For a solar tower you might expect 0.5% http://en.wikipedia.org/wiki/Solar_updraft_tower but this project is tweaked. If the heat is being stored, it is still solar power, but delta T may not be so favorable. For corn ethanol, the efficiency is about 0.06%. At this level of efficiency for energy production/storage competes with food production so it is not all that feasable. But, algae get close to PV efficiency http://mdsolar.blogspot.com/2007/02/photosynthesis .html. So, in terms of land use, I'm trying to figure out where this falls.

I wonder how this would be for growing winter crops as well: is the ground warmed eough? And, if it is, what kind of losses might be expected owing to water evaporation from soil?