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idal power is taken from the Earth's oceanic tides; tidal forces are periodic variations in gravitational attraction exerted by celestial bodies. These forces create corresponding motions or currents in the world's oceans

Because the Earth's tides are ultimately due to gravitational interaction with the Moon and Sun and the Earth's rotation, tidal power is practically inexhaustible and classified as a renewable energy resource

Because the Earth's tides are ultimately due to gravitational interaction with the Moon and Sun and the Earth's rotation, tidal power is practically inexhaustible and classified as a renewable energy resource

Drilling and exploration for deep resources is very expensive. Forecasts for the future of geothermal power depend on assumptions about technology, energy prices, subsidies, and interest rates. Pilot programs like EWEB's customer opt in Green Power Program [6] show that customers would be willing to pay a little more for a renewable energy source like geothermal. But as a result of government assisted research and industry experience, the cost of generating geothermal power has decreased by 25% over the past two decades.[7] In 2001, geothermal energy cost between two and ten cents per kwh.[8]

Wind is a clean source of renewable energy that produces no air or water pollution.

Wind is the movement of air from an area of high pressure to an area of low pressure. In fact, wind exists because the sun unevenly heats the surface of the Earth. As hot air rises, cooler air moves in to fill the void. As long as the sun shines, the wind will blow. And as long as the wind blows, people will harness it to power their lives.

The wind spins the blades, which turn a shaft connected to a generator that produces electricity. Other turbines work the same way, but the turbine is on a vertical axis and the blades look like a giant egg beater.

The first windmills in Europe appear in sources dating to the twelfth century. These early European windmills were sunk post mills. The earliest certain reference to a windmill dates from 1185, in Weedley, Yorkshire, although a number of earlier but less certainly dated twelfth century European sources referring to windmills have also been adduced.

The first windmill used for the production of electricity was built in Scotland in July 1887 by Prof James Blyth of Anderson's College,

just over 843,000 kilowatt-hours of electricity were provided by solar power. The vast majority of that, more than 666,500 kWh, were produced in California. Roughly 14 percent of the total renewable energy generated in the U.S. in 2008 was solar energy. And remember that these numbers continue to grow each year. The solar industry has been growing on an average of 30-40 percent each year, and as the industry grows, so will the amount of clean, renewable power it puts out. Interested in Home Solar Energy? Fill in your details below and certified solar contractors will give you FREE estimates. What type of Solar Energy services are you interested in? * Please Select Solar Electrical Solar Thermal First Name * Last Name * Zipcode *

The EIA states that just over 843,000 kilowatt-hours of electricity were provided by solar power. The vast majority of that, more than 666,500 kWh, were produced in California. Roughly 14 percent of the total renewable energy generated in the U.S. in 2008 was solar energy. And remember that these numbers continue to grow each year. The solar industry has been growing on an average of 30-40 percent each year, and as the industry grows, so will the amount of clean, renewable power it puts out.

When sunlight strikes a solar cell, electrons are knocked loose. They move toward the treated front surface. An electron imbalance is created between the front and the back. When a connector, like a wire, joins the two surfaces a current of electricity occurs between the negative and positive sides

The first electricity-generating wind turbine was a battery charging machine installed in July 1887 by Scottish academic James Blyth to light his holiday home in Marykirk, Scotland.[7

Tidal stream generators (or TSGs) make use of the kinetic energy of moving water to power turbines, in a similar way to wind turbines that use wind to power turbines. Some tidal generators can be built into the structures of existing bridges, involving virtually no aesthetic problems. Likewise, “tidal bridging” is a relatively new advancement that is gaining recognition as a more practical and beneficial way to generate tidal power.

Every hour the sun beams onto Earth more than enough energy to satisfy global energy needs for an entire year. Solar energy is the technology used to harness the sun's energy and make it useable. Today, the technology produces less than one tenth of one percent of global energy demand.

There were 140,000 fuel cell stacks shipped globally in 2010

although, as of 2010, no public company in the industry had yet become profitable

Solar potential from very large scale solar power plants State Land used (sq mi) Potential (GWp) Annual generation (TWh) Arizona 19,279 2,468 5,837 California 6,853 877 2,075 Colorado 2,124 272 643 Nevada 5,589 715 1,692 New Mexico 15,156 1,940 4,588 Texas 1,162 149 351 Utah 3,564 456 1,079

6,877

Total generation in the United States is about 3,800 TWh.[11]

Potential

Wave energy resources are best between 30º and 60º latitude in both hemispheres, and the potential tends to be the greatest on western coasts

While no commercial wave or tidal projects have yet been developed in the United States, several projects are planned for the near future, including projects in the Northwest

The major challenge to using wind as a source of power is that it is intermittent and does not always blow when electricity is needed. Wind cannot be stored (although wind-generated electricity can be stored, if batteries are used), and not all winds can be harnessed to meet the timing of electricity demands. Further, good wind sites are often located in remote locations far from areas of electric power demand (such as cities).

Although wind power plants have relatively little impact on the environment compared to fossil fuel power plants, there is some concern over the noise produced by the rotor blades, aesthetic (visual) impacts, and birds and bats having been killed (avian/bat mortality) by flying into the rotors. Most of these problems have been resolved or greatly reduced through technological development or by properly siting wind plants.

Sailboats and sailing ships have been using wind power for thousands of years, and architects have used wind-driven natural ventilation in buildings since similarly ancient times. The use of wind to provide mechanical power came somewhat later in antiquity. The windwheel of the Greek engineer Heron of Alexandria in the 1st century AD is the earliest known instance of using a wind-driven wheel to power a machine.[15][16].

Sustainable energy is the sustainable provision of energy that meets the needs of the present without compromising the ability of future generations to meet their needs.

Sustainable energy is the sustainable provision of energy that meets the needs of the present without compromising the ability of future generations to meet their needs.

Sustainable energy is the sustainable provision of energy that meets the needs of the present without compromising the ability of future generations to meet their needs. Technologies that promote sustainable energy include renewable energy sources, such as hydroelectricity, solar energy, wind energy, wave power, geothermal energy, and tidal power, and also technologies designed to improve energy efficiency.

Tidal power, also called tidal energy, is a form of hydropower that converts the energy of tides into useful forms of power - mainly electricity.