Toying with the idea of planting something like oilseed rape for heating oil production - I know on a small scale this isn't probably very economical as sowing and harvesting would be difficult and that's before you start trying to extract the oil but with yields of about 535 litres of oil per acre (bear in mind the leftovers are worth something as animal feed too) you could heat a home (2000l) on 4 acres (although I do know that you can only grow it every three years to prevent disease build up)
Can't quite see the point; even if you could grow and harvest it wouldn't you be better selling the product and burning the straw in a biomass boiler?
Many farmers are now installing biomass boilers, claiming the renewable heat incentive grants and just using straw to fuel it. they get their heating for nothing and get paid for it!
Personally if it's just for heating I'd have thought growing trees or coppicing them for fuel would be a better bet. i get enough fallen branches from my trees every winter to fuel my woodburner.