Biomass boilers may be a suitable option in rural areas where mains gas is not available. These boilers can burn either pellets, chips or logs. Most domestic biomass boilers run on wood pellets. If there is limited space available, the boiler can be supplied with a hopper which can be filled with pellets from bags every few days. If a pellet store can be built next to the boiler, larger deliveries can be made by lorry which can fuel the boiler for several months.
Fuel costs can be lower if you have your own wood supply. The feed system for wood chips is more expensive and you need to ensure the supply does not have too high a moisture content. A log-burning boiler needs to be regularly loaded by hand, requiring a lot of work. The efficiency of the system may be improved by using a buffer vessel which is a large insulated water tank. Although biomass boilers are much more expensive than gas or oil boilers, the Renewable Heat Incentive is available which should at least repay the cost of the boiler.