AIPG Position Statement - Domestic Energy: Environmental
AIPG Position Statement - Domestic Energy: Environmental
Douglas E. Ganey, CPG-10868
In addition to resource availability, development logistics, and political aspects, the AIPG Energy Committee also considered the environmental aspects of energy production and use. The Energy Committee statement was reviewed through an environmental protection/sustainability lens in an effort to consider the comparative environmental costs of each form of energy.
The environmental effects of each method of energy production are complex and involve environmental trade-offs. Different fuel types in varying mixes are used for different purposes (heating, power generation, transportation). Development and use of each fuel type can result in varied environmental costs (externalities) and ecological and human health risks in multiple areas. Primary environmental concerns include:
- sustainable use of hydrocarbons and mineral resources;
- greenhouse gas (GHG) emissions;
- water use;
- land, water, and air pollution;
- aesthetics; and
- waste management.
Environmental management practices during energy development are improving in preventing environmental problems. The key to minimizing environmental detriments of energy use and production is in finding the optimal fuel mix and reducing scientific uncertainty in this regard. A summary of the environmental impacts of fuel sources follows.
Fossil fuels are finite and non-renewable so using them at current rates is not a sustainable practice. Combustion of fossil fuel include and the generation of GHGs including carbon dioxide (CO2) and methane (CH4). Emissions of GHGs are perceived by some to be one of the largest, global environmental concerns related to energy production due to potential effects on the global energy system and possibly global climate. Fossil fuel use is the primary source of the increased atmospheric concentration of GHGs since industrialization (UN IPCC, 2008 and US DOE, 2008). This effect of fossil fuel combustion use causes some to consider the safety of using the remaining available fossil fuel resources.
In addition to sustainability issues and GHG emissions, there are a number of environmental issues related to mining and burning of coal, if use of coal is not controlled or managed properly. Air emissions of sulfur dioxide and nitrogen oxides from coal burning can generate acid deposition, which could be damaging to water supplies, soils, plants and wildlife, and ecosystems. Mercury emissions from burning coal can ultimately produce methylmercury when deposited in aquatic systems and acted on by anaerobic organisms. Methylmercury is toxic and may enter the food stream from aquatic systems.
Without proper management, acid mine drainage can result when water drains through tailings that are also exposed to oxygen after coal has been removed. Minerals in the tailings can be converted to acid (e.g. iron sulfide to sulfuric acid) when in contact and air, resulting in discolored, low pH runoff that can be detrimental to downstream ecosystems, soils, wildlife, and surface and ground water supplies. Additional downstream deterioration in water quality can result from introduction of toxic trace metals and increased dissolved solids, which block light and therefore reduce dissolved oxygen content.
Mountaintop removal, a form of strip mining that blasts the tops off mountains and dumps leftover rock in valleys, affects streams and ecosystems. Other negative aesthetic effects of coal mining operations include dust, vibrations, and exhaust odors.
Waste management issues with coal mining include disposal of ash waste and mining tailings that can include uranium, thorium, and other heavy metal contaminants.
Coal mining operations can also have multiple significant ecosystem effects primarily habitat destruction. Land disturbance impacts can be short or long-term and can include species displacement or destruction. Coal mining can also lead to top soil erosion.
Oil and Gas combustion contributes GHG (CO2 and CH4) and nitrogen oxide emissions, albeit less than coal burning. Compared to coal, natural gas generation produces half as much CO2, less than 1/3 as much nitrogen oxides, and 1% as much sulfur oxides (US EPA, 2009). Additional air emissions are generated during the extraction, processing, and transport of oil and gas prior to use in power plants and vehicles.
Some water use is required for cooling natural gas-fired boilers and combined cycle systems do require water for cooling purposes. When power plants remove water from a lake or river, fish and other aquatic life can be killed, affecting animals and people who depend on these aquatic resources.
Other environmental issues related to oil and gas production and use include land use issues such as drilling in environmentally sensitive areas (e.g. Alaska National Wildlife Refuge). Offshore drilling and related seismic explorations can disturb marine environments. Large oil spills have caused significant damage to marine and coastal ecosystems. Use and storage of petroleum products on land has resulted in spills and leaks from storage tanks, resulting in significant land and groundwater pollution. Environmental impacts of oil shale mining include many of the same land use, waste management, and water and air pollution impacts of coal.
Carbon Dioxide Sequestration
Carbon dioxide sequestration is a formative concept related to management and storage of carbon emissions so that the concentration of atmospheric CO2 does not increase. Carbon sequestration can be a physical capture and separation process, or refer to biological “carbon sinks” such as replanted forests. These biological sinks have limited capacity, and are temporary (for the life of the plants acting as the sink). Geological sinks can include coal seams, oil reservoirs, and salt dome formations. Carbon sequestration is currently unproven and environmental benefits and detriments are not yet certain.
Nuclear power plants produce no GHG emissions, sulfur dioxides, nitrogen oxide, or heavy metal air pollutants. However, mining and extraction of uranium utilizes fossil fuel and results in some GHG emissions. Environmental issues, while manageable and preventable, include sustainability of uranium resources, environmental damage from mining operations, thermal pollution discharge to receiving waters, accidental release of radioactivity to the environment from a power plant, effects of cooling water withdrawal on ecosystems, and radioactive waste management, including spent fuel and mining tailings.
Other Resources (“Renewables”)
Other Resources include geothermal power, hydroelectric power, biofuels, tidal and ocean thermal energy, and heat pumps. These energy sources are renewable and therefore may be more sustainable than fossil fuels. There are, however mineral requirements for some of these energy forms that present sustainability issues and other environmental issues described below. In general these renewable resources are dependent on environmental conditions (e.g. sufficient precipitation, current velocity, proximity to geothermal energy source, etc.) and are relatively scarce in terms of replacing the existing fossil fuel energy supply.
Hydroelectric power involves the construction of dams that can have adverse effects on the ecology of river systems and downstream water supplies. Salmon and other fish populations have declined along rivers where dams have restricted them from their spawning grounds.
Geothermal energy uses some water resources in energy extraction and production but has generally lower water and land use requirements than other forms of energy. Geothermal energy also produces minimal air emissions, and minimal GHGs. Some geothermal steam or fluid can contain toxic metals which could be discharged during operation of a geothermal plant.
During use of solar energy, it is a renewable energy source with no water use or GHG emissions. Development of this energy source and construction of solar panels does use non-renewable resources including scarce strategic metals for construction of photovoltaic systems and solar-thermal devices. The production of photovoltaic wafers creates small amounts of hazardous waste. Solar-thermal devices require significant use of land, which can affect wildlife and ecosystems. Water resources are often scarce in areas where solar energy is currently produced. Solar-thermal technologies sometimes require water to create steam.
Wind energy generates no air emissions or wastewater discharge and little solid waste. Water use for wind energy generation is minimal; if there is insufficient rainfall, water is used to clean the turbine blades and maintain performance. Wind energy sites can require significant tracts of land, but this land can also have other uses. Wind energy generation can also occur offshore. Environmental issues related to wind energy can include aesthetic and noise concerns, and bird and bat mortality.
Biofuels includes biodiesel, bioalcohols (e.g. ethanol) biogas (primarily methane), biomass, and various advanced biofuels, (e.g. derived from algae). Using biomass makes use of existing agricultural waste. Burning of biomass produces nitrogen oxides and some SO2, albeit less than coal. Burning biomass also produces GHGs; however, these GHGs would be introduced into the atmosphere with vegetative decay eventually, unlike most mined fossil fuels.
Similarly, biogas is derived from landfill waste, consisting of CH4, CO2, and volatile organic compounds (VOCs).
Bioalcohol production uses large amounts of water and cropland, thereby reducing area available for food production. Production of bioalcohols generates GHGs including water vapor, CO2 and methane. Development of advanced biofuels is in its early stages. Water used in power plants using all types of biofuels affects water supplies and aquatic communities. Water returned to aquatic systems after use in these power plants can contain pollutants, including heat. Some ash waste is also produced from burning biofuels
Tidal power produces no GHGs or other wastes during generation. There are potential impacts on plants and animals in coastal areas and estuaries from tidal energy facilities. Wave and ocean current energy has also produced no GHGs. Non-corrosive plastics used for constructing these facilities generate hazardous waste in their production. There is limited data to date on the ecological effects of these facilities. Other environmental issues associated with tidal and wave energy include noise pollution, aesthetic issues, and potential interference with beach sand nourishment.
Hester, R.E. and Harrison, R.M., editors. Sustainability and Environmental Impact of Renewable Energy Resources, Issues in Environmental Science and Technology, No. 19, The Royal Society of Chemistry, 2003.
International Atomic Energy Agency Bulletin. Review of the Environmental Impact of Nuclear Energy. E.E. El-Hinnwai, 1978.
United Nations Intergovernmental Panel on Climate Change (UN IPCC). Fourth Assessment Report: Climate Change 2007, Working Group I Report "The Physical Science Basis" http://www.ipcc.ch/ipccreports/ar4-wg1.htm , 2008.
United Nations Intergovernmental Panel on Climate Change (UN IPCC). Special Report on Carbon Dioxide Capture and Storage. http://www.ipcc.ch/ipccreports/srccs.htm, 2005.
U.S. Department of Energy (US DOE), Energy Information Agency. International Energy Outlook 2008, http://www.eia.doe.gov/oiaf/ieo/index.html
U.S. Environmental Protection Agency (US EPA), Clean Energy website., http://www.epa.gov/solar/index.html 2009.
U.S. Environmental Protection Agency (US EPA), Effects of Acid Rain website., http://www.epa.gov/acidrain/effects/index.html 2009.