When energy is converted from one form to another, a less useful form results. Energy cannot be recycled to a higher quality.
The process that reduces the negative environmental effects of burning coal. This process includes washing coal to remove minerals and impurities and capturing the sulfur dioxide and carbon dioxide from the flue gases.
A recently discovered source of methane that form at low temperature and high pressure. They are found on land in permafrost regions and beneath the ocean floorat water depths greater than 1,640 ft where high pressues dominate.This source of methane amounts to approximately 3,000 times the volume of methane in the atmosphere.
This future energy source contains organic material called kerogen. If heated in the absence of air, the kerogen converts to oil. This source can be extracted from surface minimg or the in-situ method of mining.
This source of future energy contains bitumen which is a semisolid form of oil that does not flow. Specialized refineries are capable of converting bitumen to oil.
The softestform of coal that has the lowest heat content.
Soft form of coal that has a high sulfur content and constitutes 50% of the US coal reserve.
A hard form of coal that has a high heat content and low sulfur content. It makes up 2% of the US coal reserve.
Pre-coal that is used in some countries for heat but it has a low heat content.
Environmental Advantages of Coal
1. Abundant, known world reserves will last approximately 300 years at current rate of consumption. 2. Unidentified world reserves are estimated to last 1,000 years at current rate of consumption. 3.. United States reserves are estimated to last about 300 years at current rate of consumption. 4. Relatively high-net energy yield. 5. U.S. subsidies keep prices low. 6. Stable, nonexplosive; not harmful if spilled.
Environmental Cons of Coal
1. Most extraction in the United States is done through either strip mining or underground mining. There methods cause disruption to the land through erosion, runoff, and decrease in biodiversity. 2. Up to 20% of coal endsup as fly ash, boiler slag, or slugde. Burning coal releases mercury, sulfur, and radioactive particles into the air. 35% of all CO2 releases are due to the burning of coal, with 30% of all pollution due to NOX. 3. Underground minimg is dangerous and unhealthy. 4. Expensive to process and transport. 5. Pollution causes golabal warming. Scrubbers and other antipollution control devices are expensive.
Environmental Pros to Oil
1. Inexpensive, however, prices are increasing, making alternatives more attractive. 2. Easily transported through established pipelines and distribuition networks. 3. High-net energy yield. 4. Ample supply for immediate future. 5. Large U.S. Government subsidies in place. 6. Versitile- used to manufacture many products.
Environmental Cons to Oil
1. World reserves are limited and declining. 2. Produces pollution. (NOx, CO2, SO2) 3. Causes land disturbances in drilling process, which accelerates erosion. 4. Oil spills both on land and in ocean from platforms and tankers. 5. Disruption to wildlife habitats (ex: Artic Wildlife Refuge) 6. Supplies are politically volatile.
Pros to Natural Gas
1. Pipelines and distribution networks are in place. Easily transported and processed as LNG over rail or ship. 2. Relatively inexpensive, but prices are increasing. 3. World reserves are estimated to be 125 years at current rate of consumption. 4. High net energy yield. 5. Produces less pollution than any other fossil fuel. 6. Extraction is not as damaging to the environment as either coal or oil.
Cons to Natural Gas
1. H2S and SO2 are released during processing. 2. LNG processing is expensive and dangerous, and results in lower net energy. 3. Leakage of CH4 has a greater impact on global warming than CO2. 4. Disruption to areas where it is collected. 5. Extraction releases contaminated waterwaste and brine. 6. Land subsidence.
Pros of Nuclear Power
1. No air pollutants if opperating correctly. 2. Releases about 1/6 the CO2 as fossil fuel plants. 3. Water pollution is low. 4. Disruption of land is low to moderate.
Cons of Nuclear Power
1. Nuclear wastes take millions of years to degrade. Problem of where to store them and keeping them out of the hands of terrorists. 2. Current facilites have a lifespan of only 15-40 years. 3. Low net-energy yeild- energy required for mining uranium, procdessing ore, building and operatins plant, dismantaling plant and storing wastes. 4. Safety and malfunction issues.
Pros to Hydroelectric Power
1. Dams control flooding. 2. Low operating and maintenance costs. 3. No polluting waste products. 4. Long life spans. 5. Moderate to high net-useful energy 6. Areas of water recreation
Cons to Hydropower
1. Dams create large flooded areas behind the dam which people are displaced. Water is slowly moving and can breed pathogens. 2. Dams destroy wildlife habitats and keep fish from migrating. 3. Sedimentation requires dredging. Prevents sedimentation from reaching downstream and enriching farmland. 4. Expensive to build. 5. Destroys wild rivers. 6. Large-scale projects are subject to earthquakes.
Straightens and deepens streams in attempt to control flooding. Cons include: removes bank vegitation and increases stream velocity -> caused erosion; may increase downstream flooding and sedimentation -> negatively impacts aquatic habitats
Pros of Solar Energy
1. Supply of Solar energy is limitless. 2. Reduces reliance on foreign imports. 3. Only pollution is in manufacture of collectors. Little environmental impact. 4. Can store energy during the day and release it at night- good for remote locations.
Cons of Solar Power
1. Inefficient where sunlight is limited or seasonal. 2. Maintenance costs are high. 3. Systems deteriorate and must be replaced periodically. 4. Current efficiency is between 10%-25% and not expected to increase soon.
Pros of Hydrogen Fuel Cells
1. Waste product is pure water 2. Ordinary water, either ocean or freshwater, can be used to obtain hydrogen. 3. Does nto destroy wildlife habitats and has minimal environmental impact. 4. Energy to produce hydrogen could come from fusion reactor, solar, or other less polluting source. 5. Hydrogen is easily transported through pipelines. 6. Hydrogen can be stored in compounds to make it safe to handle. Hydrogen is explosive, but so are methane, propane, butane, and gasoline.
Cons of Hydrogen Fuel Cells
1. Takes energy to produce hydrogenfrom either water or methane. 2. Changing from a current fossil fuel system to a hydrogen-based system would be very expensive. 3. Hydrogen gas is explosive. 4. At the current time, it is difficult to store hydrogen gas for personal cars.
Any carbon-based, biologically derived fuel source such as wood, manure, charcoal or bagasse.
Pros to Biomass
1. Renewable energy source as long as used sustainably. 2. Rate of use balanced with rate of renewable does not disrupt atmospheric CO2 levels. 3. Less SO2 and NOx produced than by burning fossil fuels. 4. Can be sustainable if the issue of deforestation and soil erosion are controlled. 5. Could supply half of the worlds demand for electricity. 6. Biomass plantations can be located in less desirable locations and can reduce soil erosion and restore degraded land.
Cons to Biomass
1. Requires adequate water and fertilizer, of which sources are declining. 2. Use of inorganic fertilizers, herbicides, and pesticides would harm the environment. 3. Would cause massive deforestation and loss of habitat, resulting in a decrease of biodiversity. 4. Inefficient methods of burning biomass would lead to large levels of air pollution, especially particulate matter. 5. Expensive to transport because it is heavy. 6. Not efficient. About 70% of the energy derived from burning biomass is lost as heat.
Pros to Wind Power
1. All electrical needs of the US could be met by wind in ND, SD and TX. 2. Wind farms can be easily built and can also be built out on sea platforms. 3. Maintenance is low and the farms are automated. 4. Moderate to high net energy yield. 5. No pollution. 6.. Land underneath wind turbines can be used for agriculture (Multi-use)
Cons to Wind Power
1. Steady wind is required to make investment in wind farms economical. 2. Backup systems need to be in place when the wind is not blowing. 3. Visual pollution. 4. May interfere with flight patterns of birds. 5. May interfere with communication, such as TV and cell phones. 6. Noise pollution.
Pros to Tidal Power
1. No pollution. 2. minimal environmental impact. 3. Net energy yield is moderate.
Cons to Tidal Power.
1. Construction is expensive. 2. Few suitable sights. 3. Equipment can be damaged by storms and erosion.
Pros of Geothermal Power
1. Moderate net energy yeild. 2. Limitless and reliable source if managed properly. 3. Little air pollution. 4. Competitive cost.
Cons of Geothermal Power
1. Reservior sites are scarce. 2. Source can be depleated if not managed properly. 3. Noise, odor, land subsidence. 4. Can degrade ecosystem due to corrosive, thermal, or saline wastes.