On Dec 16, 5:47*pm, " wrote:
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?


Just like with heating a house, you save by having it at a lower temp
and then bringing it to desired temp when needed. The only exceptions
would be if energy rates were different at different times of the day,
or if a different energy source were used, eg in winter a heat pump
might kick in electric heat to raise the temp quickly. In the case of
an electric water heater though, the cost savings of setting it back
for say 8 hours isn't going to amount to much at all. In that time,
it won't cool very much.




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.- Hide quoted text -

- Show quoted text -


The only real cost factor from an operating standpoint is the amount
of electricity it takes to cover the standby heat loss of a 50 gallon
tank vs an 80 gallon one. And I would think that could be easily
offset or more by the fact that with solar the 80 offers more storage
and less likely to need some of the electric to raise the temp.