Cons of Wood Burning Systems
- When wood burns, it releases hazardous gases (such as nitrogen oxides and carbon monoxide) and soot (also known as particulate matter) into the air. Therefore wood energy appliances and facilities must be designed and permitted to meet air quality regulations and standards.
- The upfront, capital cost of building a sizeable wood energy facility can be high, so it can take years to see the savings from lower fuel cost.
- Steady use requires a continuous supply of wood chips or other biomass.
- Wood systems require more space to store bulky fuel.
- Compared with conventional boiler systems, wood systems require a larger boiler to handle the fuel.
- Waste ash that remains after burning needs proper, safe disposal.
- Automated wood chip conveyor systems and fuel-handling equipment must be monitored closely to prevent jams and system shutdowns.
- Wood chip fuel can vary by size, moisture content, and energy content. Standard un-dried, or “green,” fuel contains 30-55% water, which slows combustion.
- Equipment to dry wood chips and improve efficiency is very expensive. (Note that dry wood is highly flammable, so requires safer handling and more sophisticated boiler systems.)
- Most pellet stoves require some electricity to operate.