Biomass heating systems, touted for their cost-effectiveness and environmental benefits, pose significant health risks due to increased air pollution from small installations. Airparif reports that these low-power systems emit harmful pollutants, particularly fine particles, at much higher rates than larger units. Although wood heating represents a small fraction of energy use in Île-de-France, it contributes significantly to fine particle emissions, exceeding those from German coal-fired plants, raising serious environmental concerns.
Understanding Biomass Heating: A Double-Edged Sword
Biomass heating systems have emerged as a potential solution for providing cost-effective and eco-friendly warmth. These systems play a significant role in the decarbonization of energy use and can help lower heating expenses through the utilization of wood. However, recent studies reveal a concerning downside: their impact on public health. This was underscored by Airparif in a report released on March 27.
The Health Risks of Small Biomass Heating Systems
According to Airparif, the air quality monitoring agency in Île-de-France, there has been a notable rise in the number of small biomass heating systems that rely on wood. Despite their growing popularity, these low-power installations are responsible for emitting harmful air pollutants including carbon oxides and fine particles, which pose health risks.
These smaller biomass systems are often found in various public buildings such as hospitals, nursing homes, and schools. While larger biomass systems typically have better combustion efficiency and pollution control, the increasing trend towards smaller systems—often below 500 kilowatt-hours—raises concerns. These smaller systems lack the advanced filtration technologies and regulatory oversight that govern larger installations, resulting in higher emissions of particulate matter.
Antoine Trouche, an engineer specializing in press relations and scientific communication, emphasizes the significance of fine particles, stating that small biomass systems generate about six times more fine particles (PM 2.5) when using wood pellets compared to their larger counterparts. The situation worsens when forest chips are used, leading to emissions that are 15 times higher due to the less efficient combustion process.
When comparing these small systems to individual pellet boilers or stoves, Airparif notes that while there is a 53% reduction in fine particle emissions with pellets, the opposite is true for forest chips, which increase emissions by 17%. In contrast, other heating options, such as heat pumps and geothermal networks, produce negligible air pollutants and minimal greenhouse gases.
To mitigate pollution from biomass heating systems, Airparif recommends several strategies: ensuring the boiler is appropriately sized for heating needs, optimizing air circulation to reduce excess air that can increase fine particle emissions, and selecting the right fuel type—favoring pellets over forest chips, which contain higher levels of sodium and potassium that contribute to PM2.5 emissions.
Beyond the immediate concerns surrounding biomass heating systems in buildings, the use of wood heating in Île-de-France presents additional challenges. Although wood heating accounts for only 7% of the region’s total energy consumption for heating, lighting, and cooking, it is a significant source of fine particle emissions. Airparif highlights that these emissions surpass those from all German coal-fired power plants, raising alarms about the environmental impact of wood combustion, which can also generate CO2 and methane, two major greenhouse gases.