Renewables:Biomass

From Sustainable Building Resource

[edit] Biomass

Combustion of biomass is considered carbon neutral, as the CO2 released into the atmosphere is the same amount that was absorbed by photosynthesis during its growth phase.

Direct combustion of biomass in a central biomass boiler would replace the traditional gas boilers, providing low carbon space heating and hot water. Biomass boilers come in different formats:

Liquid biomass (to replace oil).

These can be retro-fitted, but the biomass liquid is more 'abrasive' and so pipes will need to be replaced otherwise increased corrosion will result.

Logs

Gasifying log boilers are now really efficient and worth investigating. Quality and consistency of logs is a factor though.

Pellets

Pellets come is a variety of qualities and also levels of sustainability. Modern pellet boilers require more heavily on higher quality pellets. This gives increased efficiencies so care must be taken when ordering pellets. Reputation is important here.

Some pellets are made from recycled wood, others from saw dust from saw mills, others are direct from the forest.

In the UK we actually import pellets from abroad. These tend to be the higher quality ones, but they therefore have added 'pellet-miles'

Chips

Chips are the cheaper option to pellets, but they do require more storage space and also specialised delivery systems. Pellets tend to use gravity in domestic applications, but you will need a store and a auger feed for wood chips. This requires space and more capital investment.

Experience