Estimate kWh electricity needed to heat new addition?
I am planning to expand an existing room in my house. The room is currently on a separate heating zone (oil heat, forced hot water). I have solar panels and generate an average 1700 kWh electricity per year more than I use (this is a 3 year average). So I am thinking of heating the remodeled room with electric baseboard, hoping that I can essentially heat it for free with the excess kilowatts that I generate. But I would like to project how much electricity will be required before making a decision. Can this be estimated?
The room will be 13′ x 17′ (221 square feet).
Ceiling will slant up from 7′ to 15′ so total volume is about 2400 cubic feet.
Total 125 square feet of double-pane glass (two sliding doors plus windows), facing NE and NW.
Closed cell icynene spray foam insulation.
Located near Boston, MA.
Can someone estimate how many kWh per year would be required to heat this? Thank you in advance.