PV panels required to power electrical boiler to replace propane boiler
I am considering replacing my 25 year old propane boiler (which I’m told is at most 80% efficient) used to heat my hydronic floors, with a new, high efficiency, electric boiler to heat both the floors and DHW, and powering it with photovoltaic panels. Before I get too deep into it though, I want to guesstimate how many PV panels would be required to run this system.
My current propane consumption is about 1400 gallons per year. We use propane for 1) hydronic floor heating 2) 50 gal DHW tank 3) stove top cooking 4) clothes dryer and 5) hot tub. The hot tub is only cranked up perhaps a dozen times a year and the clothes drier is used 1-2 a week. Online estimates suggest 90-95% of my total consumption would have been used on DHW & floor heat.
My question is therefore, how big a PV solar array would be required to deliver the same amount of heat from a +/- 95% efficiency electric boiler as is currently produced by burning 1300 gallons of propane in an 80% efficient gas boiler.
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