Alternatives to coal plants

According to 2009 estimates, coal is used to generate approximately 41% of the world's electricity, with an additional 13% (717 million tonnes) used for iron and steel production, and a smaller percentage for cement production. This article discusses some of the proposed alternatives to coal plants, including various forms of renewable energy, conservation and efficiency, natural gas, biomass, and nuclear energy.

Renewable Energy

Renewable energy is defined by the U.S. Department of Energy as energy derived "from resources that are regenerative or for all practical purposes can not be depleted. Types of renewable energy resources include moving water (hydro power, tidal and wave power), thermal gradients in ocean water, biomass, geothermal energy, solar energy, and wind energy. Municipal solid waste (MSW) is also considered to be a renewable energy resource."

Microgeneration is the generation of renewable, zero or low-carbon heat and power by individuals, small businesses, and communities to meet their own energy needs, which can smooth out demand on electric grids.

Here are some articles that discuss renewable energy as an alternative to coal:

• Geothermal power as an alternative to coal - Geothermal power (from the Greek roots geo, meaning earth, and thermos, meaning heat) is power extracted from heat stored in the earth. Geothermal energy is generated in the Earth's core, where temperatures hotter than the sun's surface are continuously produced by the slow decay of radioactive particles. Enhanced geothermal systems (EGS) use heat-mining technology to extract and utilize the earth’s stored thermal energy. A 2006 report by MIT and funded by the U.S. Department of Energy on EGS found that U.S. EGS resources far exceeded the country’s energy use in 2005, and that with an R&D investment of $1 billion over 15 years, EGS could be capable of producing electricity for as low as 3.9 cents/kWh.

• Photovoltaic power as an alternative to coal - Photovoltaics (PVs) are arrays of cells containing a solar photovoltaic material that converts solar radiation into direct current electricity. Materials presently used for photovoltaics include monocrystalline silicon, polycrystalline silicon, microcrystalline silicon, cadmium telluride, and copper indium selenide/sulfide.

• Thermal solar power as an alternative to coal - Solar thermal energy (STE) is a technology for harnessing solar energy for thermal energy (heat).

• Wind power as an alternative to coal - Wind power is the conversion of wind energy into a useful form of energy, such as using wind turbines to make electricity, wind mills for mechanical power, wind pumps for pumping water or drainage, or sails to propel ships. At the end of 2009, worldwide nameplate capacity of wind-powered generators was 159.2 gigawatts (GW) and energy production was 340 terawatt hour (TWh), or about 2% of worldwide electricity usage.

Conservation and efficiency programs as an alternative to coal

The 2010 report Beyond Business as Usual: Investigating a Future without Coal and Nuclear Power in the U.S. by Synapse Energy Economics found that "aggressive investments" in more efficient technologies in every sector of the U.S. economy could reduce electricity use within the country by 15% from 2010 requirements, or over 40% from the “business as usual” scenario as laid out by the U.S. Energy Information Administration, which projects energy usage increasing through 2035. The Synapse report notes that utilities in several states are already achieving savings at this level.

According to work done for the California Public Utility Commission (CPUC) on how to comply with the AB32 law (California’s Global Warming Solutions Act), energy efficiency is the cheapest alternative to burning coal. California has cut annual peak demand by 12 GW – and total demand by about 40,000 GWh — through a variety of energy efficiency programs over the past three decades. Over their lifetime, the cost of efficiency programs has averaged 2-3¢ per kW. According to this research, if every state had the per capita electricity of California, electricity use would lower some 40%.

In 2004, the American Council for An Energy-Efficient Economy (ACEEE) released a study summarizing the results of eleven studies of the potential for energy efficiency nationwide. The study found results of "technical" (i.e. unconstrained by economics or the practical reality of implementation) savings ranging from 18% to 36%, "economic" (i.e. cost-constrained) potential ranging from 13% to 27%, and "achievable" (i.e. constrained by the rate of actual adoption) potential ranging from 10% to 33%. The time frame for realizing the potential savings ranged from 5 to 20 years. Overall, the survey of studies concluded that the achievable savings potential for electricity is about 1.2% per year of program implementation.

Natural gas as an alternative to coal

Natural gas, often referred to as simply gas, consists primarily of methane. It is found associated with fossil fuels, in coal beds, as methane clathrates, and is created by methanogenic organisms in marshes, bogs, and landfills. It is commonly used in coal plant conversion projects because it is seen as a cleaner burning fuel. However, natural gas, while producing less carbon dioxide than coal or oil, does emit carbon into the atmosphere. Before natural gas can be used as a fuel, it must undergo extensive natural gas processing to remove almost all materials other than methane. The by-products of that processing include ethane, propane, butanes, pentanes and higher molecular weight hydrocarbons, elemental sulfur, carbon dioxide, water vapor, and sometimes helium and nitrogen.

Natural gas is a major source of electricity generation through the use of gas turbines and steam turbines. Natural gas burns more cleanly than other fossil fuels, such as oil and coal, and produces less carbon dioxide per unit energy released. For an equivalent amount of heat, burning natural gas produces about 30% less carbon dioxide than burning petroleum and about 45% less than burning coal. However, the radiative forcing of methane - a potent greenhouse gas - is 72 times that of carbon dioxide averaged over 20 years (or 25 times that of carbon dioxide averaged over 100 years), and it is believed that using natural gas on a large scale will mean increased amounts of methane will leak into the atmosphere.

The major difficulty in the use of natural gas is transportation and storage because of its low density. Natural gas pipelines are economical, but are impractical across oceans. Many existing pipelines in North America are close to reaching their capacity, prompting some politicians representing colder areas to speak publicly of potential shortages. In Europe, the gas pipeline network is already dense in the West.

Most of the remaining domestic gas reserves are so-called “unconventional” deposits trapped in shale, coal and sandstone formations. To free the gas, companies pump chemicals, sand and water into the ground under high pressure to fracture the rock formations, a process called fracking. Hydraulic fracturing fluids contain a toxic cocktail of petroleum distillates—benzene, toluene and other carcinogens (the precise recipe is a trade secret). The fractured formations are then dewatered to release the gas.

In 2005, Congress exempted gas drillers from provisions of the Safe Drinking Water Act by passing the “Halliburton loophole,” inserted into the law at the request of a former Halliburton executive, then vice president Dick Cheney. The 2005 Energy Bill also exempted drillers from storm water runoff provisions of the Clean Water Act. And Congress has provided exemptions from certain provisions of the Clean Air Act, the National Environmental Policy Act, and the Emergency Planning and Community Right to Know Act—allowing gas companies to avoid reporting their toxic emissions to the Environmental Protection Agency’s (EPA) Toxics Release Inventory."

The conservation group American Rivers reported in June 2010 that the Upper Delaware River is now the "most endangered river" in the United States due to natural gas drilling in New York and Pennsylvania. The group contended that the drilling above Marcellus Shale using hydraulic fracturing to extract 3 and 9 million gallons of water per drilling well, would put the river in further peril. The American Rivers report noted that "two companies alone--Chesapeake Appalachia and Statoil--have announced their intention to develop up to 17,000 gas wells in the region in next 20 years." The documentary Gasland shows homeowners talking about how their water has been discolored, or was starting to bubble, since gas fracking operations began near their water supplies. In some communities, people were able to light the water coming out of their faucets on fire, because chemicals from the natural gas drilling process had seeped into the water, an event documented in the film.

Biomass as an alternative to coal

The term biomass generally includes any organic material that is not a fossil fuel. The National Renewable Energy Laboratory (NREL) defines biomass as "any plant-derived organic matter. Biomass available for energy includes herbaceous and woody energy crops, agricultural food and feed crops, agricultural crop wastes and residues, wood wastes and residues, aquatic plants, and other waste materials including some municipal wastes."

Environmental impacts

The majority of coal-fired power plant conversion projects to date are centered on switching to biomass fuel sources. Biomass generally includes any organic material that is not a fossil fuel. The National Renewable Energy Laboratory (NREL) defines biomass as "any plant-derived organic matter. Biomass available for energy on a sustainable basis includes herbaceous and woody energy crops, agricultural food and feed crops, agricultural crop wastes and residues, wood wastes and residues, aquatic plants, and other waste materials including some municipal wastes."

Support for biomass within the environmental community is mixed. Supporters identify biomass as an improvement over coal, touting benefits that include significant reductions in the emissions of sulfur dioxide, nitrogen oxides, and mercury.

However, critics point out that no combustion technologies actually mitigate greenhouse gas emissions, and that the focus of a new energy policy should be on energy conservation and zero-emissions technologies like geothermal, wind, and solar. Further, while biomass technologies may be touted as carbon-neutral, due to the CO2 captured by biomass before burned, in practice this may not be the case. Studies suggest that in reality, the carbon released by burning would take decades to remove from the atmosphere, because of the length of time necessary to replenish harvested tree and plant material and re-sequester the equivalent amount of CO₂.

Biomass also presents other issues. In terms of emissions, it releases approximately the same amount of particulate matter as coal and fifty percent more carbon monoxide and carbon dioxide. A 2010 Massachusetts study “Biomass Sustainability and Carbon Policy Study” found that 135MW of biomass energy generation would produce 482 tons of nitrogen oxides, 617 tons of carbon monoxide, 165 tons of particulate matter, and 2.2 million tons of CO₂. The 2010 study, commissioned by Massachusetts state environmental officials, also found that biomass-fired electricity would result in a 3 percent increase in carbon emissions compared to coal-fired electricity by the year 2050 if those trees were harvested in New England forests.

The cultivation and clearcutting of biomass materials on a large scale also bear major implications for wildlife habitats, biodiversity, water supplies, as well as a potential depletion in the terrestrial carbon sink..

Health impacts

According to Biofuels Watch and the American Lung Association of New England, the majority of biomass power plants emit toxic air pollution, depending on air pollution controls at the facility, that cause asthma, heart disease, respiratory failure, and create other medical complications. For the smokestack emissions that matter most to climate change and public health – carbon dioxide, NOx and particulates, per unit of power produced, biomass burning is said to be worse than coal. Additionally these plants emit the most harmful toxins: both dioxin and mercury. Particulate emissions are of grave concern as they are worse than those from coal plants per megawatt of electricity produced. The American Lung Association of New England has stated “Burning biomass could lead to significant increases in emissions of nitrogen oxides, particulate matter and sulfur dioxide and have severe impacts on the health of children, older adults, and people with lung disease.” In 2009 the Association urged Congress to exclude biomass burning from the federal climate legislation.

The Massachusetts Medical Society (representing 22,000 doctors and publisher of the New England Journal of Medicine) in February of 2010 testified to the state legislature of Massachusettes that biomass burning presents an “unacceptable risk to the public’s health by increasing air pollution.”

Nuclear power as an alternative to coal

Nuclear power is power (generally electrical) produced from controlled nuclear reactions. Commercial plants in use to date use nuclear fission reactions. Electric utility reactors heat water to produce steam, which is then used to generate electricity. About 15% of the world's electricity comes from nuclear power, despite concerns about safety and radioactive waste management.

The negative effects of nuclear power include radioactive waste such as depleted uranium, high initial investment to construct a plant (and thus large government subsidies), slow implementation, large uses of water, and risk of nuclear proliferation, as well as nuclear accidents, such as Chernobyl. The benefits include lower carbon dioxide emissions and high electrical energy. There are also hopes that future nuclear technology will have more energy output and less waste. For more, go to Nuclear power as an alternative to coal.

Articles and Resources

Related GEM.wiki articles

• alternative fuels
• CLEAN Energy Act of 2007
• climate change / global warming
• Concentrating solar power land use
• Conservation and efficiency programs as an alternative to coal
• Energy Bulletin
• Geothermal power as an alternative to coal
• National Commission on Energy Policy
• National Energy Policy
• Nuclear power as an alternative to coal
• Nuclear PR
• oil depletion
• peak oil / peak oil: we have oil
• Peak Oil Caucus
• Photovoltaic power as an alternative to coal
• Renewable and Sustainable Energy APG
• Richard H. Truly
• Thermal solar power as an alternative to coal
• U.S. tax breaks for renewable energy
• Wind power as an alternative to coal

External articles

General

• Is 450 ppm possible: part 5 Climate Progress
• renewable energy in the Wikipedia.
• "Database of State Incentives for Renewables & Efficiency" (includes interactive map).
• Guide: "Renewable Energy Nonprofit Organizations in the World".
• "Earth & Climate: Renewable Energy News," ScienceDaily.
• "Getting Wind and Sun onto the Grid: A Manual for Policy Makers ," IEA.
• "A ROADMAP FOR FINDING FLEXIBILITY IN WHOLESALE MARKETS," Energy Innovation.

Websites

• Renewable Fuels Association (US) website.
• U.S. Department of Energy:

• Energy Efficiency and Renewable Energy web page.
• Energy Information Administration web data on "Renewable and Alternative Fuels".

Organizations

• Solartopia.org.

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