mcallis said:If I'm right here the concept is the geothermal heat will warm the barrel at night. Are Temperatures at this depth constant at higher longitudes? Meaning up here in Mass would the ground heat at 4 feet deep be significantly different?
If I was the one you were asking about, no, I don't think burying a barrel 4 feet down would collect any measurable amount of geothermal heat. It might be below the frost line, and be insulated against daily temperature changes.
Maybe in a region with hot springs or volcanoes it would be different.
I just meant that barrels could absorb solar heat, and the warmed water allowed to flow down into an underground reservoir. Then, you could pump cold water up out of the reservoir and back into the barrels for re-heating. That way, the temperature difference between the water and the barrels' walls would stay large, and heat absorption would increase.
