Have you considered switching to LPG?
Yes i have considered all sorts of solutions. LPG, Solid fuel both pellet type boilers and stove based, ground air or water sourced heat pumps, solar and even a stirling engine!.
But all of them are more expensive to run and the installation costs would be astronomical.
New LPG tank and pipes removal of all the oil related stuff .... tank and pipes and i think an lpg tank could not go where the oil tank is so a new site would have to be made, concrete base ect.
if british gas would do the last 4 miles of gas pipe installation to our village then i would probably switch to gas but i dont think going the lpg route would be a good idea for me.
I am always open to ideas ......
Andy