On Dec 16, 4:30�pm, infiniteMPG wrote:
You need pro advise , maybe alt.energy.homepower �I would be thinking to not heat the tank but use it for solar storage, if its near hot enough a cheap small electric 20-30a �tankless would be far more efficent, for single use it probably would be all you need.

Looked at the tankless but are they not more for point of use then
whole house? �And the ones that are whole house cost more then the 80
gallon lifetime tank.

but what about a cloudy week or month.

In west central Florida near the coast and it's rare to have a couple
days without enough sunlight to get hot water. �And the Gray Box
cranks on the electric heater just before dawn so the morning shower
is never cold, even with cloudly/stormy days. �:O)

Kind of brings up another question. �If you have a hot water heater
and (for this example) NO solar, if you turn the heater off for most
part of the day and then on in time to heat water for an evening
shower, does it cost more to heat a cool or cold tank of water then it
would to just maintain it all hot all day long???? �Kind of like that
old AC question, better to leave it on all the time rather then try to
cool and hot house when you get home?

your far better going for the larger tank, it costs not much more and
allows storage for cloudy days, a smaler tank would be a resale killer
when that time comes.

turning off heat does save a little, but the real improvement for you
will be the added efficency of a new tank and its superior foam
insulation.