If I understand correctly, one correctly sized tankless could supply enough
hot water for all the appliances plus showers and baths at the same time. As
for the electric outages, a UPS - uninterruptible power supply, just for the
controls - should take care of that.

My concern is the reliability, and I hear some of the tankless heaters are
not good. I've been using hot water dispensers for years and those tanks
goes out about 5 years (something always goes out in about 5 years) and I
just couldn't justify replacing a tankless every 5 or even 10 years. Hot
water heater: $500, Tankless: $3,000. Tankless has to save a lot of energy
to justify the extra cost. Anyone know what the payback is for tankless?

the payback period exceeds the expected life of the unit, say 10 years
thats the longest warranty on a tankless. any companies locally for
service?

so for 500 bucks you can get a standard tank with a 12 year warranty.
you would have to save more than 2500 bucks before saving a dime in
energy. check the energy guide labels of tanks thats probably the
entire operating cost of a regular tank. mine says 250 bucks a year,
times 10 years wheres the savings?

worse assuming your tank in in a heated part of the home the wasted
energy in the heating season helps heat your home so its not wasted at
all....... for the heating season. true its a loser for AC

new regular tanks are actually very efficent, you can get higfher btu
models and larger tanks for never run out showers if you want. my 50
gallong 75,000 btu is near that, next tank will be 75 gallons, the 50
barely fit my existing space.... new furnace and more space.

think of another thing regular tanks are actually very reliable, other
than spring a leak at end of life few have other troubles and are a
bargain at 500 bucks.

you could likely save a few hundered a year in heating costs for your
new home by doubling wall thickness and upgraded insulation...... at
say 30 grand extra.

thats not a good deal either