PV Gap

Caroline Said:

Solar to heat the water in our house? Cost?

We Answered:

Can't answer directly, as ROI will depend on how you can situate the solar panels and how much freezing weather you get -- a simple system that will handle hot water in summer but has to be drained in winter is cheap and easy. The ones involving heat exchangers that can be used in freezing weather are more complex and expensive.

http://www.energy.vt.edu/vept/renewables…

Eduardo Said:

why is the shape of a solar collector to heat water important?

We Answered:

Using a solar collector to heat water needs to be parabolic / curved in order to focus the heat on your water pipe (or whatever your whatever you water is being contained in). Just putting your pipe (as is used in a solar reflectivity plant) in front of a flat mirror would do essentially nothing. Focusing the Sun's rays (sort of like a magnifying glass) greatly increases the amount of thermal energy ("heat") that you're putting into that water. Put in that pipe, and properly shape the reflector, and you'll make a solar reflectivity plant useful enough to actually... use.