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The coal powder mixes with hot air, which helps the coal burn more efficiently, and the mixture moves to the furnace. The burning coal heats water in a boiler, creating steam. Steam released from the boiler powers an engine called a turbine, transforming heat energy from burning coal into mechanical energy that spins the turbine engine. The spinning turbine is used to power a generator, a machine that turns mechanical energy into electric energy. This happens when magnets inside a copper coil in the generator spin.

Electricity-generating plants send out electricity using a transformer, which increases the voltage of the electricity based on the amount required and the distance it must travel. Voltages are often as high as 500,000 volts at this point.  Electricity flows along transmission lines to substation transformers. These transformers reduce the voltage for use in the local areas to be served.  From the substation transformers, electricity travels along distribution lines, which can be either above or below the ground, to cities and towns. Transformers once again reduce the voltage—this time to about 120 to 140 volts—for safe use inside homes and businesses. The delivery process is instantaneous. By the time you have flipped a switch to turn on a light, electricity has been delivered.

Method Cents/kW-h Limitations and Externalities WindCurrently supplies approximately 1.4% of the global electricity demand. Wind is considered to be about 30% reliable. 4.0 - 6.0 Cents/kW-h Wind is currently the only cost-effective alternative energy method, but has a number of problems. Wind farms are highly subject to lightning strikes, have high mechanical fatigue failure, are limited in size by hub stress, do not function well, if at all, under conditions of heavy rain, icing conditions or very cold climates, and are noisy and cannot be insulated for sound reduction due to their size and subsequent loss of wind velocity and power. GeothermalCurrently supplies approximately 0.23% of the global electricity demand. Geothermal is considered 90-95% reliable. 4.5 - 30 Cents/kW-h New low temperature conversion of heat to electricity is likely to make geothermal substantially more plausible (more shallow drilling possible) and less expensive. Generally, the bigger the plant, the less the cost and cost also depends upon the depth to be drilled and the temperature at the depth. The higher the temperature, the lower the cost per kwh. Cost may also be affect by where the drilling is to take place as concerns distance from the grid and another factor may be the permeability of the rock. HydroCurrently supplies around 19.9% of the global electricity demand. Hydro is considered to be 60% reliable. 5.1 - 11.3 Cents/kW-h Hydro is currently the only source of renewable energy making substantive contributions to global energy demand. Hydro plants, however, can (obviously) only be built in a limited number of places, and can significantly damage aquatic ecosystems. SolarCurrently supplies approximately 0.8% of the global electricity demand. 15 - 30 Cents/kW-h Solar power has been expensive, but soon is expected to drop to as low as 3.5 cents/kW-h. Once the silicon shortage is remedied through alternative materials, a solar energy revolution is expected.

Tide 2 - 5 Cents/kW-h Blue Energy's tidal fence, engineered and ready for implementation, would provide a land bridge (road) while also generating electricity. Environmental impact is low. Tides are highly predictable.

Method Cents/kW-h Limitations and Externalities GasCurrently supplies around 15% of the global electricity demand. 3.9 - 4.4 Cents/kW-h Gas-fired plants and generally quicker and less expensive to build than coal or nuclear, but a relatively high percentage of the cost/KWh is derived from the cost of the fuel. Due to the current (and projected future) upwards trend in gas prices, there is uncertainty around the cost / KWh over the lifetime of plants. Gas burns more cleanly than coal, but the gas itself (largely methane) is a potent greenhouse gas. Some energy conversions to calculate your cost of natural gas per kwh. 100 cubic feet (CCF)~ 1 Therm = 100,000 btu ~ 29.3 kwh. CoalCurrently supplies around 38% of the global electricity demand. 4.8 - 5.5 Cents/kW-h Increasingly difficult to build new coal plants in the developed world, due to environmental requirements governing the plants. Growing concern about coal fired plants in the developing world (China, for instance, imposes less environmental overhead, and has large supplies of high sulphur content coal). The supply of coal is plentiful, but the coal generation method is perceived to make a larger contribution to air pollution than the rest of the methods combined.

Wind power generates electricity with... No air emissions No fuel to mine, transport, or store No cooling water No water pollution No wastes

Wind power can reduce pollution generated by fossil fuels such as coal, oil, and gas. A typical (750 kW) wind turbine provides enough power for 328 typical (non-electric heating) homes.

Wind energy is cost-competitive with fossil fuels, especially coal. In Montana, wind energy is less expensive than coal for NorthWestern Energy--the state's largest utility.

ccording to the EIA, the total cost of wind energy without federal tax and other financial incentives is about 9.7 cents/kilowatt-hour. The total cost of conventional coal without federal tax and other financial incentives is about 9.4 cents/kilowatt-hour.

here are integration costs associated with intermittent renewable energy but unlike fossil fuels, wind (and solar and many other renewables) the fuel price stays the same: Zero.  Plus, wind-power technology has rapidly evolved. Turbines are much larger, growing from an average of 1.2 megawatts to 1.6 megawatts (a 33% increase in average capacity) in just three years.

Geothermal electricity generation does involve a small amount of geothermal pollution in that the steam coming up from below ground carries some toxic gases, but in most plants these gases, as well as the steam, are condensed and reinjected into the ground so the effect on the environment is negligible. There are no CO2 emissions from geothermal energy so it is a much better source of electricity than coal or natural gas or nuclear (or even large-scale hydro generation which requires the flooding of large areas of land).

Geothermal electricity generation does involve a small amount of geothermal pollution in that the steam coming up from below ground carries some toxic gases, but in most plants these gases, as well as the steam, are condensed and reinjected into the ground so the effect on the environment is negligible. There are no CO2 emissions from geothermal energy so it is a much better source of electricity than coal or natural gas or nuclear (or even large-scale hydro generation which requires the flooding of large areas of land).

Geothermal electricity generation does involve a small amount of geothermal pollution in that the steam coming up from below ground carries some toxic gases, but in most plants these gases, as well as the steam, are condensed and reinjected into the ground so the effect on the environment is negligible. There are no CO2 emissions from geothermal energy so it is a much better source of electricity than coal or natural gas or nuclear (or even large-scale hydro generation which requires

One of the most important is that wind power is the least expensive of all other forms of alternative energy.  Wind turbines generate electricity at around 5 cents per kWh (Kilowatt Hour), which is comparable to the new coal and/or oil burning power plants.  The costs are projected to decline even more as technology improves, and this is very important because most of the cost with wind power is in manufacturing.  Once the wind turbines are in place there is little cost to maintain and wind power is free.

One of the most important is that wind power is the least expensive of all other forms of alternative energy.

Another tremendous benefit of wind power is that it is a sustainable source of energy and a clean source of energy

3. You cannot transport geothermal energy. I used to live in the coal region of Pennsylvania. For years coal trucks used to drive by our front door hauling Anthracite coal to home and industries.

4. There may be geothermal gases. Geothermal steam and hot water do contain naturally occurring traces of hydrogen sulfide (a gas that smells like rotten eggs) and other gases and chemicals that can be harmful in high concentrations.

Archeologists have also found evidence that the Romans in England used it in the second and third centuries (100-200 AD). 

In the 1700s, the English found that coal could produce a fuel that burned cleaner and hotter than wood charcoal.

They were formed from prehistoric plants and animals that lived hundreds of millions of years ago.

Some coal deposits, however, were formed from freshwater swamps which had very little sulfur in them. These coal deposits, located largely in the western part of the United States, have much less sulfur in them

What is U.S. electricity generation by energy source? In 2012, the United States generated about 4,054 billion kilowatthours of electricity.  About 68% of the electricity generated was from fossil fuel (coal, natural gas, and petroleum), with 37% attributed from coal. Energy sources and percent share of  total electricity generation in 2012 were:  Coal 37% Natural Gas 30% Nuclear 19% Hydropower 7% Other Renewable 5% Biomass 1.42% Geothermal 0.41% Solar 0.11% Wind 3.46% Petroleum 1% Other Gases < 1%

Unsubsidized wind power is now cheaper than electricity produced from new coal- and natural gas-fired power stations in Australia, according to an analysis by Bloomberg New Energy Finance. The study said that electricity can be supplied from a new wind farm at a cost of 80 Australian dollars per megawatt hour, compared to 143 Australian dollars from a new coal plant and 116 Australian dollars from a new natural gas plant.

In 2006, wind power supplied 0.6% of US electricity but reduced CO2 emission from electricity production by a full 1%.

What really matters is the cost to society. With current subsidy methods, it costs around 3¢/kWh

  One-Time Cost per kW Capacity (usage) Factor Fixed Cost per kWh Variable Cost per kWh Total Cost per kWh Gas Turbine $439 15% 5.2¢ 8.7¢ 13.9¢ Coal $1,338 90% 2.7¢ 1.9¢ 4.5¢ Nuclear $2,180 90% 4.3¢ 0.3¢ 4.6¢ Wind $1,254* 30% 7.5¢ 0.0¢ 7.5¢