What is the cheapest way to heat your home? I'll crunch the numbers for a house in Nova Scotia.
Electric baseboard heaters are cheap to install, but expensive to use. The current cost of electricity in NS is 14.6c/kWh tax in. With one kWh of electricity providing 3412 BTU of heat, electric heating costs 4.28c/kBTU.
If you use the time-of-day tariff, off-peak electricity costs 8.15c/kWh tax in. That reduces electric heating costs at night and weekends to 2.39c/kBTU.
Furnace oil is selling for $1/L, and provides ~36kBTU when burned. With a 90% efficient condensing boiler, the cost is 3.09c/kBTU.
Discount propane sells for ~60c/L at Costco, and provides ~26kBTU when burned. With a 90% efficient condensing boiler, the cost is 2.56c/kBTU.
Wood pellets provide ~8kBTU/lb, and sell for ~$5 for a 40lb bag. At 90% efficiency, the cost of heat is 1.74c/kBTU.
Heating with wood pellets is pretty cheap, but still not the cheapest. A geothermal heating system will have a COP of at least 3.0 (4.0 can be achieved with new high-efficiency heat pumps). Take the 4.28c/kBTU cost of electricity and divide by the COP (3.0) to get a heating cost of only 1.43c/kBTU. With a time-of-day tariff and off-peak use, the rate is just 0.8c/kBTU.
Don't forget the cheapest (free) source of heat - the sun. So on those sunny winter days, open the curtains, raise the blinds, and let the sun shine in!