Dimitrios Paskoudniakis wrote:

I'm talking about heating the basement and first floor of my house, and
whether I should change from fuel oil to something else, so I don't pay
$4.50 per gallon...

How about solar heat from a sunspace on the south side of the house, eg a
lean-to greenhouse? Each $1 square foot of sunspace glazing can provide
the heat equivalent of 1-2 gallons of oil per year. With a little more
work, it can also heat water for showers.

Nick