Monetizing the Health Impacts of Wood Smoke in the Pacific Northwest April 10, 2014

1. Monetizing the Health Impacts of Wood Smoke in the Pacific Northwest April 10, 2014

2. Project Overview • Task A – Collect Data • Task B – Estimate Baseline Wood Smoke Emissions • Task C – Estimate Scenario Wood Smoke Emissions • Task D – Monetize Health Impacts

3. Baseline Wood Smoke Emissions • Data sources used to estimate baseline wood smoke emissions include the Residential Building Stock Assessment (RBSA) and the U.S. EPA Residential Wood Combustion (RWC) tool • RWC Tool: all counties in Oregon & Washington; Ada, Canyon, & Elmore, Idaho; Lincoln & Silver Bow, Montana • RBSA: all other counties in Idaho and Montana

4. Baseline Wood Smoke Emissions Baseline methodology relies on two key factors: • Appliance fraction: the percentage of homes in the county with each type of wood burning appliance • Burn rate:the amount of wood (cords or tons) burned in each appliance in each year • Unique appliance fractions and burn rates are calculated for each combination of appliance type, burn type, and house type

5. Baseline Wood Smoke Emissions

6. Baseline Wood Smoke Emissions Baseline emissions calculation: • Baseline emissions (tons) = Number of homes × Appliance fraction × Burn rate (cords/year) × Density of firewood (tons/cord) × Emission factor (tons of pollution/tons of wood) Number of appliances Number of cords Convert cords to tons Calculate tons of pollution

7. Scenario Wood Smoke Emissions • Scenarios reduced emissions for all appliances used primarily for heating: • All types of wood stoves, pellet stoves, wood-fired furnaces, and wood-fired boilers • Did not include fireplaces or outdoor burning (e.g. firepits); these emissions were left unchanged • Analysis included 4 scenarios: • 25% reduction • 50% reduction • 75% reduction • 100% reduction

8. Baseline and Scenario Emissions

9. Monetized Health Impacts: Method • U.S. EPA’s Co-Benefits Risk Assessment (COBRA) model Modified the baseline for wood smoke emissions to match estimates for the PNW Adjusted the outputs for population and income growth to match council values

10. Monetized Health Impacts: Adjustments • Population adjustments • Using county-level ratios of the Council’s 2017 population projections to the 2017 population in COBRA • Income growth adjustments • For economic values, based on willingness-to-pay estimates • Using the ratio of Council data-based income growth adjustment factors to the factors supplied by EPA

11. Monetized Health Impacts: Results • Avoided cases of adverse health effects, and their associated economic values • “Low” and “high” estimates based on different (EPA-approved) assumptions about sensitivity of adult mortality and non-fatal heart attacks to changes in ambient PM2.5levels • COBRA discounts the estimated stream of economic benefits to the year 2017, since some health benefits from 2017 emissions reductions will occur in later years

12. Monetized Health Impacts: Results Health Incidence Results for Study Area

13. Monetized Health Impacts: Results Monetized Value Results for Study Area

14. Monetized Health Impacts: Results Total Health Benefits in 2017 Avoided Adult Mortality in 2017

15. Monetized Health Impacts: Results Improvements in Ambient Air Quality mg/m3 PM2.5

16. Monetized Health Impacts: Results Total Health Benefits

17. Monetized Health Impacts: Results Changes in PM2.5 Emissions Value of Total Health Effects Avoided

18. Monetized Health Impacts: Results Comparing Health Benefits to Increased Electricity Usage • Estimated the amount of electricity needed to displace wood heat with ductless heat pumps (DHPs): • Usable heat to displace (kWh) = Wood burned (tons) × Btu/ton of wood × Appliance Efficiency × kWh/Btu • Grid DHP Electricity Consumption (kWh) = Usable heat from woodstoves / DHP COP × Grid Loss Factor • Benefits per kWh = Total Health Benefits / DHP Electricity Consumption • Total benefits for PNW study area: $0.72 - $1.61 per kWh of electricity used by a DHP to displace wood heat

19. Applications and Limitations • Applications • Significant annual health benefits across PNW study area identified by screening-level assessment provide justification for performing a more in-depth analysis of benefits associated with wood smoke emissions reductions • A value range ($/kWh) that can be used in a benefit-cost analysis of policies or programs that target the entire PNW study area to replace wood burning appliances with DHPs • A customized version of COBRA to allow future scenario analyses • Limitations • Results can only be interpreted at the study-area level; more analysis is needed to determine more spatially targeted results (e.g. county level) • Results only examine benefits, but do not include costs of reducing wood smoke or for increases in emissions from EGUs (e.g. to power DHPs) • Analysis does not fully account for all uncertainties, including population and income projections and air dispersion algorithms

20. Suggested Future Analyses • Spatially targeted results • Current results can only be interpreted across the entire study area • Spatially targeted results would look at smaller (e.g. county-level) areas to determine benefits of emission reductions on a smaller spatial scale • Compare benefits to costs of reducing wood smoke emissions • Incentives to reduce burning and/or to install DHPs or other heating devices • Education campaigns to inform residents about wood smoke emissions • Regulations to control wood smoke emissions • Examine emissions from redispatching electricity • The current analysis does not adjust the benefits to account for any emissions that might arise due to an increase in use of DHPs to displace wood heat

21. Acknowledgements Special thanks to: • Mohit Chhabra, Ptarmigan Research • Charlie Grist, Northwest Power and Conservation Council • RTF Wood Smoke Subcommittee • Ben Larson, David Baylon, Ecotope Inc.; Christian Douglass, Ptarmigan Research

22. Questions? Abt Contact Information Jonathan G. Dorn, Ph.D., M.P.P Jonathan_Dorn@abtassoc.com 919-294-7763