Description of the Technology

Biomass combustion simply means burning organic material. For millennia, humans have used this basic technology to create heat and, later, to generate power through steam.

While wood is the most commonly used feedstock, a wide range of materials can be burned effectively. These include residuals and byproducts such as straw, bark residuals, sawdust and shavings from sawmills, as well as so-called "energy crops" such as switchgrass, poplar and willow that are grown specifically to create feedstock. Pelletized agricultural and wood residues are also an increasingly popular option because they are very easy to handle.

Farmers and other rural homeowners are increasingly looking to biomass heat as an economical alternative to propane or furnace oil. Stoves and fireplaces can provide direct space heating or be hooked up with a back boiler that feeds heated water to radiators throughout the building.

One recent technology advance is the introduction of pellet stoves, which use an electrically driven auger to deliver a steady supply of compressed pellets of wood or other biomass into the fire. These stoves can operate for at least 24 hours without being tended.

On a larger scale, biomass-fed boilers can be used to meet hot water needs, heat a building or generate steam to power equipment. Many farmers are choosing to use them as the primary heat source in greenhouses, where they heat very large spaces.

State of the Industry

Biomass combustion is clearly a proven technology, but design improvements over the past couple of decades have helped to increase its efficiency, reduce emission levels and reduce costs.

At the same time, the creation of professional certification programs for installers and inspectors has helped to boost the safety of biomass combustion systems.

Although biomass combustion is not uncommon, Natural Resources Canada estimates that Canada is currently meeting only six per cent of our energy demand this way, leaving plenty of untapped potential.

Is Biomass Combustion Right for Me?

If you have access to suitable feedstock, along with a place to store it, biomass combustion systems can be an attractive option, saving you money compared to conventional fuel systems.

However, keep in mind they require more maintenance and oversight. On top of that, some feedstocks require preparation – wood that must be sized and sorted before you can burn it, for example.

Basic Numbers

According to the Integration of Renewable Energy on Farms website, capital costs for biomass combustion range from $50-120 per megajoule of energy delivered, while feedstock costs vary. The life expectancy of a stove or boiler is virtually unlimited.

Benefits and Drawbacks

Benefits

  • Provides a relatively cheap fuel source
  • Reduces reliance on fossil fuels
  • Provides self-sufficiency, even during blackouts (except for pellet stoves that require electricity to run the auger motors and fans)

Drawbacks

  • Fuel quality and consistency can vary significantly
  • Produces more indoor and outdoor air pollution than conventional heating fuels, even with the use of advanced combustion technology
  • Creates the risk of fire and carbon monoxide poisoning
  • Can require cutting wood, as well as the skill to lay fires
  • Requires regular tending and maintenance
  • Fuel storage requires a lot of space

Planning Issues and Regulations

Some municipalities may require a building permit, even if you're replacing an older wood stove with a new one, while others have restrictions on outdoor boilers. Contact your local municipality to find out what permits, approvals and bylaws apply.

You should also advise your insurance agent if you are installing a new system.

Setting Up and Operating a Biomass Combustion System

To reduce air pollution, look for stoves, fireplaces, furnaces or boilers that meet Canadian Standards Association standard CSA B415.1 or have been certified as clean burning by the U.S. Environmental Protection Agency. As well, use only well-dried fuel – a smoldering fire creates more air pollution.

For maximum safety and performance, have your system installed by a WETT-certified professional and make sure it meets CSA B365 Installation Code for Solid-Fuel-Burning Appliances and Equipment. Place smoke detectors and carbon monoxide detectors nearby, and keep a fire extinguisher within easy reach.

Once your system is in place, be prepared for a certain amount of work to operate it, including supplying the fuel, lighting and tending the fire, and cleaning out the ashes it creates.

Regular maintenance is important to reduce the risk of chimney fires and to keep everything operating efficiently. Each year, have a certified professional check and clean the entire system.

Additional Resources

Publications

For wood-based systems, see Canada Mortgage and Housing Corporation's A Guide to Residential Wood Heating and the Insurance Bureau of Canada's Is Your Wood Stove Safe?.

Natural Resources Canada's Buyer's Guide to Small Commercial Biomass Combustion Systems focuses on larger-scale systems and covers various feedstocks.

If you're interested in corn stoves, check the Ontario Ministry of Agriculture, Food and Rural Affairs' factsheet on Burning shelled corn as a heating fuel.

Associations