PV Gap

Kim Said:

how do you create a water heater from solar power?

We Answered:

It depends on how hot you want your water. If you want only moderately heated water, suitable for bathing, you can use a box covered with glass that has a long winding pipe inside it. The pipe should be a small diameter and laid out flat on the bottom of the box with as many turns in it as possible to increas the length. This can go into a reservoir, like a hot water tank, and to make it more sophisticated you can put a circulating pump on the tank that constantly circulates the water through the heating panel. This is how commercial solar water heaters are made, with some sophisticated controls added.

If you want to boil your water using solar power this can be done with a parabolic mirror that focuses sunlight onto your cooking pot. These can be made from small pieces of mirror laid in a parabolic form (shaped like a satelitte dish) and cemented with plain grout. I have seen these used in some areas and they are quite effective.

One simple method that I use when camping: Lay a black colored bag of water on the ground or hang it in the sun and wait till it is warm enough for a shower.

Karen Said:

A water heater is operated by solar power. If the solar collector has an area of 6.50 m2, and the intensity...

We Answered:

conservation of energy requires
mc[t(final)-t(initial)]=ISxtime
time=mc[t(final)-t(initial)]/IS
m=Volumexdensity
All the data in the problem are in SI so you obtain time in seconds.
m mass c, specific heat, t temperature I intensity, S surface