PV Gap

Barry Said:

BEST ANSWER 10 POINTS!!! HELP!!!! How many showers per day could be supported by a single hot water panel? How?

We Answered:

Solar constant is 1000 watts per square meter.

if we take that number with no losses, then over 5 hours that is 5000 watt-hours, 5 kW-hrs

Say 20 gallons of water per shower, that is 0.08 m³ or 80 kg
say we have to heat the water from 20C to 50C
specific heat of water is 4.186 kJ/kgC
E = 4.186 kJ/kgC x 80 kg x 30C = 10000 kJ or 3 kW-hours

so 5/3 = 1 2/3 showers.


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Sara Said:

Solar Hot Water System?

We Answered:

Yes, but it would be terribly inefficient.

You can get hot water from solar energy in one step, skipping the motor-generator entirely.