17 research outputs found
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Modelling renewable electric resources: A case study of wind
The central issue facing renewables in the integrated resource planning process is the appropriate assessment of the value of renewables to utility systems. This includes their impact on both energy and capacity costs (avoided costs), and on emissions and environmental impacts, taking account of the reliability, system characteristics, interactions (in dispatch), seasonality, and other characteristics and costs of the technologies. These are system-specific considerations whose relationships may have some generic implications. In this report, we focus on the reliability contribution of wind electric generating systems, measured as the amount of fossil capacity they can displace while meeting the system reliability criterion. We examine this issue for a case study system at different wind characteristics and penetration, for different years, with different system characteristics, and with different modelling techniques. In an accompanying analysis we also examine the economics of wind electric generation, as well as its emissions and social costs, for the case study system. This report was undertaken for the {open_quotes}Innovative IRP{close_quotes} program of the U.S. Department of Energy, and is based on work by both Union of Concerned Scientists (UCS) and Tellus Institute, including America`s Energy Choices and the UCS Midwest Renewables Project
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The potential for biomass to mitigate greenhouse gas emissions in the Northeastern US
This study, for the Northeast Regional Biomass Program (NRBP) of the Coalition of Northeast Governors (CONEG), evaluates the potential for local, state and regional biomass policies to contribute to an overall energy/biomass strategy for the reduction of greenhouse gas releases in the Northeastern United States. Biomass is a conditionally renewable resource that can play a dual role: by reducing emissions of greenhouse gases in meeting our energy needs; and by removing carbon from the atmosphere and sequestering it in standing biomass stocks and long-lived products. In this study we examine the contribution of biomass to the energy system in the Northeast and to the region's net releases of carbon dioxide and methane, and project these releases over three decades, given a continuation of current trends and policies. We then compare this Reference Case with three alternative scenarios, assuming successively more aggressive efforts to reduce greenhouse gas emissions through strategic implementation of energy efficiency and biomass resources. Finally, we identify and examine policy options for expanding the role of biomass in the region's energy and greenhouse gas mitigation strategies
Annual emissions and air-quality impacts of an urban area district-heating system: Boston case study
A district-heating system, based on thermal energy from power plants retrofitted to operate in the cogeneration mode, is expected to improve local air quality. This possibility has been examined by comparing the emissions of five major atmospheric pollutants, i.e., particulates, sulfur oxides, carbon monoxide, hydrocarbons, and nitrogen oxides, from the existing heating and electric system in the City of Boston with those from a proposed district heating system. Detailed, spatial distribution of existing heating load and fuel mix is developed to specify emissions associated with existing heating systems. Actual electric-power-plant parameters and generation for the base year are specified. Additional plant fuel consumption and emissions resulting from cogeneration operation have been estimated. Six alternative fuel-emissions-control scenarios are considered. The average annual ground-level concentrations of sulfur oxides are calculated using a modified form of the EPA's Climatological Dispersion Model. This report describes the methodology, the results and their implications, and the areas for extended investigation. The initial results confirm expectations. Average sulfur oxides concentrations at various points within and near the city drop by up to 85% in the existing fuels scenarios and by 95% in scenarios in which different fuels and more-stringent emissions controls at the plants are used. These reductions are relative to concentrations caused by fuel combustion for heating and large commercial and industrial process uses within the city and Boston Edison Co. electric generation