Impacts of Federal Clean Air Law on District-Heating Opportunities

摘要

District heating facilities are likely to be easier to site in attainment areas - those that have achieved National Ambient Air Quality Standards (NAAQS) - than in areas where these standards have not been met (nonattainment areas). Under review procedures aimed at Prevention of Significant Deterioration (PSD) of air quality in attainment areas, approval would be virtually automatic if a district heating plant would result in net air quality improvement. Thus, district heating proponents would do well to focus their efforts on servicing existing buildings in areas that have attained NAAQS for particulate matter, sulfur dioxide, and nitrogen dioxide. In a nonattainment area, actual emission reductions - not merely air quality improvements - must be produced before a new plant can be approved during New Source Review (NSR). Converting conventional electric plants to cogeneration may produce emission reductions from individual furnace shutdowns in the buildings to be serviced by the plants sufficient to offset emission increases from the plant itself. Thus, NSR approval is most readily available for such conversions, and the focus of any efforts to employ district heating technology in nonattainment areas should be on converting existing conventional plants to cogeneration. No exemptions from NSR or PSD review requirements now exist for district heating systems. Nor do present emission offset regulations governing NSR account for the phenomenon, associated with some district heating configurations, of air quality improvement despite emission increases. Existing statutory provisions would have to be amended before the US Environmental Protection Agency (EPA) can implement either a blanket district heating exemption or a case-by-case waiver of the emission offset requirement where air quality benefits are expected. (ERA citation 06:033770)