Solar Hot Water

I was looking at our demands if we tried to source most of our heating load by Solar, it would not be logical to size a system for our worst case situation:

Average winter btu load after insulation infiltration issues addressed 300,000btu

Storage required – 14 hours

BTU Production per sq ft of collector per day, average:

Winter 1,000

Summer 2,000

Storage required to get through average winter night 14x300,000 = 4,200,000

Storage per million btu’s = 2,000 gallons

Total storage required 8,500 gallons

Solar sq footage required about 6,000

Back up required for harsh weather low solar production

By comparison I worked out we would only need 200 sq ft to provide most of our hot water in the summer.