For most of humanity’s existence, biomass heating in homes in the form of wood burning stoves and furnaces was the only way to provide warmth. Today, fossil fuels, which leave a heavier carbon footprint, are the primary way home heating occurs. Regardless of fossil fuel prices, many people today are concerned about the acquisition of fuel for warmth as well as other energy needs. Whether it is oil from the Gulf of Mexico or Saudi Arabia, or oil from shale mined in Colorado and North Dakota, there are a growing number of people who are increasingly nervous about being plugged into a system they have no control over.
In the middle of the decision-making process to switch from conventional energy sources to a biomass system for the home comes the reality of measuring cost versus value.
For example, you may look at a pellet-fired system and determine that though its more expensive to operate, you can do so knowing it’s a little friendlier to the environment plus the added advantage of functioning off the grid. There are two main types of heating using biomass equipment.
Typically, these units burn wood logs or the newer condensed product known as pellets. Stoves can be modified to include a back boiler for hot water use in kitchens and bathrooms. I general, stoves produce approximately 7Kw of energy with an efficiency rating somewhere between 60% and 80%.
This heating unit is bigger and has a design that is more industrial in nature. The wood boilers produce anywhere from 20Kw to 50Kw in energy and you have to keep stoking them regularly. If you pursue the pellet boiler option, its energy output has a maximum of 30Kw. It often includes a hopper for the pellets which is handy when you can’t manually supply the biomass material every few hours yourself. As described above, the three main types of wood fuel are logs and pellets but there are wood chips that are available as well.
- Logs are often easier to acquire and require very little preparation before use. However, they do require up to three years to dry out so that the moisture content at or below 20%. This is necessary for a hotter burning log with less smoke. Logs also require larger amounts of storage and must be manually fed into the boiler.
- Wood chips can be a good source of energy, however, you need a steady supplier of these forestry clippings. For home use, the chips have to be a standard size and with little moisture.
- Wood pellets come from saw dust. Their moisture content is generally between 8% and 10%. Because of this, they are more energy dense than the previous two types mentioned above. Additional ideal factors include less storage space and their uniform size and shape, which works well with automated systems.
Cost Versus Savings
So how much does all this conversion from fossil fuels to biomass energy cost? It will depend on several factors.
- How much energy is needed?
- Is the home well insulated?
- Can a lower cost manual system work for you or do you need something a little more automated?
- Are you more concerned about potential environmental damage than operating costs?
A log burning stove might cost approximately $2,000. A pellet stove without an automatic feeder is likely to be $4K to $5K, while the auto-feed boiler type could cost $8K to $10K.
The savings you generate from your biomass system will largely depend on the source you are using now such as, natural gas, oil, coal, electric or propane. Across the spectrum of these sources you may save $100 to $750 per year. The carbon savings will be ranked accordingly as well.
Before engaging in any energy conversion projects keep the following in mind:
- Consult local planning boards and follow all ordinances.
- Keep your supply of biomass material as close as possible so that transportation of such material doesn’t eat up all your carbon savings.
Check with current tax laws to see if you might get favorable tax treatment for such a changeover. Finally, only you can decide the real value of biomass conversion.