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Unlike fossil fuels, wave power doesn't cause air pollution.

According to studies, an economically competitive geothermal power plant can cost as low as $3400 per kilowatt installed.

Even normal

gasoline vehicles can operate on a 10 percent ethanol blend with no problems. Diesel cars and trucks can run on biodiesel, though older models may need to have their fuel lines and gaskets replaced with modern synthetic materials, since biodiesel is a solvent

biofuel

a gaseous, liquid, or solid substance of biological origin that is used as a fuel

Wind energy releases no pollution into the air or water, and does not contribute to global warming

"on average, each MWh of electricity generated in the U.S. results in the emission of 1,341 pounds of carbon dioxide (CO2)

his avoided CO2 equals over 1.8 million tons of carbon, enough to fill 180 trains, each 100 cars long, with each car holding 100 tons of carbon every year."

Biofuels or biodiesels are fuels that are, in essence, biodegradable and non-toxic. They are manufactured from vegetable oils, waste cooking oils, animal fats or tall oil (a by-product of the pulp and paper industry).

Increased biofuel demand has contributed to higher world food and feed prices.

Global biofuel production has tripled from 4.8 billion gallons in 2000 to about 16.0 billion in 2007, but still accounts for less than 3 percent of the global transportation fuel supply.

Cellulosic ethanol could raise per acre ethanol yields to more than 1,000 gallons, significantly reducing land requirements. Cellulosic ethanol is made by breaking down the tough cellular material that gives plants rigidity and structure and converting the resulting sugar into ethanol. Cellulose is the world’s most widely available biological material, present in such low-value materials as wood chips and wood waste, fast-growing grasses, crop residues like corn stover, and municipal waste.

Estimated cost of hydrogen per kilogram in a variety of scenarios With all of this in mind, here are the cost estimates per kilogram (which each include $1.25 for taxes): Hydrogen from natural gas (produced via steam reforming at fueling station) $4 – $5 per kilogram of hydrogen Hydrogen from natural gas (produced via steam reforming off-site and delivered by truck) $6 – $8 per kilogram of hydrogen Hydrogen from wind (via electrolysis) $8 – $10 per kilogram of hydrogen Hydrogen from nuclear (via electrolysis) $7.50 – $9.50 per kilogram of hydrogen Hydrogen from nuclear (via thermochemical cycles – assuming the technology works on a large scale) $6.50 – $8.50 per kilogram of hydrogen Hydrogen from solar (via electrolysis) $10 – $12 per kilogram of hydrogen Hydrogen from solar (via thermochemical cycles – assuming the technology works on a large scale) $7.50 – $9.50 per kilogram of hydrogen As mentioned above, a cost of hydrogen of $4 to $12 per kilogram is equivalent to gasoline at $1.60 to $4.80 per gallon.

Burning fossil fuels releases carbon dioxide, a heat-trapping gas, into the atmosphere, which is the main reason why the climate is changing.

The Earth is getting warmer because people are adding heat-trapping gases to the atmosphere, mainly by burning fossil fuels. These gases are called greenhouse gases. Warmer temperatures are causing other changes around the world, such as melting glaciers and stronger storms. These changes are happening because the Earth's air, water, and land are all linked to the climate

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.

Challenges Wind power must compete with conventional generation sources on a cost basis. Depending on how energetic a wind site is, the wind farm may or may not be cost competitive. Even though the cost of wind power has decreased dramatically in the past 10 years, the technology requires a higher initial investment than fossil-fueled generators. Good wind sites are often located in remote locations, far from cities where the electricity is needed. Transmission lines must be built to bring the electricity from the wind farm to the city. Wind resource development may compete with other uses for the land and those alternative uses may be more highly valued than electricity generation. Although wind power plants have relatively little impact on the environment compared to other conventional power plants, there is some concern over the noise produced by the rotor blades, aesthetic (visual) impacts, and sometimes birds have been killed by flying into the rotors. Most of these problems have been resolved or greatly reduced through technological development or by properly siting wind plants.

Advantages

Solar energy is free - it needs no fuel and produces no waste or pollution.

Handy for low-power uses such as solar powered garden lights and battery chargers, or for helping your home energy bills.

The Sun heats our atmosphere unevenly, so some patches become warmer than others. These warm patches of air rise, other air blows in to replace them - and we feel a wind blowing. We can use the energy in the wind by building a tall tower, with a large propellor on the top. The wind blows the propellor round, which turns a generator to produce electricity.

he best places for wind farms are in coastal areas, at the tops of rounded hills, open plains and gaps in mountains - places where the wind is strong and reliable. Some are offshore.

The best places for wind farms are in coastal areas, at the tops of rounded hills, open plains and gaps in mountains - places where the wind is strong and reliable. Some are offshore.

Advantages Once you've built it, tidal power is free. It produces no greenhouse gases or other waste. It needs no fuel. It produces electricity reliably. Not expensive to maintain. Tides are totally predictable. Offshore turbines and vertical-axis turbines are not ruinously expensive to build and do not have a large environmental impact. Disadvantages A barrage across an estuary is very expensive to build, and affects a very wide area - the environment is changed for many miles upstream and downstream. Many birds rely on the tide uncovering the mud flats so that they can feed. Fish can't migrate, unless "fish ladders" are installed. Only provides power for around 10 hours each day, when the tide is actually moving in or out. There are few suitable sites for tidal barrages Is it renewable? Tidal energy is renewable. The tides will continue to ebb and flow, and the energy is there for the taking.