1. Residential emissions small scale bio combustion HC Hansson ITM, Stockholm University SWEDEN

2. PM2.5 emissions by sector “with climate measures” scenario [kt] source: Marcus Amann, IIASA EU-15 New Member States Power generationIndustryDomesticTransportAgricultureIndustrial processes NEC emission ceiling Domestic

3. The major source type Domestic heating using bio combustion, a major possible sustainable energy source Might increase more than expected

4. PM-emissions, why so difficult to estimate? Wide range of emissions factors, depending on type, brand, fuel,... Large number of boilers, stoves, etc –1.1 million totally in Sweden –0.8 million totally in Finland Usage unknown, no control or monitoring on fuel

5. Emission estimates Total emissions = Σ N i x EF i x U i N i = Number of a specific type EF i = Emission factor for that type and fuel, depends strongly on handling U i = Usage (many use complementary energy source)

6. Emission estimate, Sweden PM emissions estimated to range 3 – 62000 ton /yr Former best estimate 24 000 ton/yr based on laboratory New best estimate 5 000 ton/yr based on field Estimates on N and U made by chimney sweepers

7. Other ways of making emission estimates Source receptor modeling –Depend on tracer components Potassium (part of ash fraction) –Other sources Levoglucosan (part of organic fraction) –Good tracer 14 ± 2 % of PM2.5 (Yttri et. al, 2005) –Bad tracer (Hedberg et al., 2006) PAH’s (part of organic fraction) –Other sources 14 C of PAH

8. Conclusions on emission estimates Large uncertainties with direct method Complementation with source receptor techniques or local monitoring/modeling is recommended to get local averages of EF

9. How to decrease the emission factors (EF) Support change to modern boilers with considerable lower EF Obligatory use of heat storage tank of appropriate size making maximum use of a full fire cycle Support development of more user friendly boilers, correcting for misuse Change to other heat sources; –1/ District heating, 2/ Heat pumps

10. Regulations needed Registrations of all boilers/fireplaces Common European “Environmental Label” on small scale bio combustion systems (should included heat storage tank) Forced exchange to such systems (mean age of boilers in Sweden is 20 years) Emission and usage inspection connected to chimney sweeping

11. Public / political support Conversion to sustainable energy use has high political priority Supply of wood for heating is available for increase of heating (30-50 TWh) Emissions from wood combustion is NOT a political issue in the Nordic countries Emission from small scale wood combustion is the major reason for complaints in the local environmental agencies There is a tradition on community owned district heating plants and distribution, shown to economical competitive.

12. Conclusions Considerable reduction possible Actually possible to increase the use considerable without violating AQL No national political interest UNECE / EC could facilitate large air quality improvement and in changing to a more sustainable energy policy. District heating is an economical option.