Geothermal Energy The Heat Of The Earth

Geothermal energy is energy obtained by tapping the heat of the earth itself, usually from kilometers deep into the Earth’s crust. It is expensive to build a power station but operating costs are low resulting in low energy costs for suitable sites. Ultimately, this energy derives from heat in the Earth’s core.

Three types of power plants are used to generate power from geothermal energy: dry steam, flash, and binary. Dry steam plants take steam out of fractures in the ground and use it to directly drive a turbine that spins a generator. Flash plants take hot water, usually at temperatures over 200°C, out of the ground, and allows it to boil as it rises to the surface then separates the steam phase in steam/water separators and then runs the steam through a turbine. In binary plants, the hot water flows through heat exchangers, boiling an organic fluid that spins the turbine. The condensed steam and remaining geothermal fluid from all three types of plants are injected back into the hot rock to pick up more heat.

The geothermal energy from the core of the Earth is closer to the surface in some areas than in others. Where hot underground steam or water can be tapped and brought to the surface it may be used to generate electricity. Such geothermal power sources exist in certain geologically unstable parts of the world such as Chile, Iceland, New Zealand, United States, the Philippines and Italy. The two most prominent areas for this in the United States are in the Yellowstone basin and in northern California. Iceland produced 170 MW geothermal power and heated 86% of all houses in the year 2000 through geothermal energy. Some 8000 MW of capacity is operational in total.

There is also the potential to generate geothermal energy from hot dry rocks. Holes at least 3 km deep are drilled into the earth. Some of these holes pump water into the earth, while other holes pump hot water out. The heat resource consists of hot underground radiogenic granite rocks, which heat up when there is enough sediment between the rock and the earths surface. Several companies in Australia are exploring this technology.

Geothermal Energy Prospects

The Geysers, is a geothermal power field located 72 miles (116 km) north of San Francisco, California. It is the largest geothermal development in the world outputting over 750 MW.

By the end of 2005 worldwide use of geothermal energy for electricity had reached 9.3 GWs, with an additional 28 GW used directly for heating. If heat recovered by ground source heat pumps is included, the non-electric use of geothermal energy is estimated at more than 100 GWt (gigawatts of thermal power) and is used commercially in over 70 countries. During 2005 contracts were placed for an additional 0.5 GW of capacity in the United States, while there were also plants under construction in 11 other countries

Water Power A Form Of Kinetic Energy

Energy in water (in the form of kinetic energy, temperature differences or salinity gradients) can be harnessed and used. Since water is about 800 times denser than air, even a slow flowing stream of water, or moderate sea swell, can yield considerable amounts of energy.

There are many forms of water energy:

Hydroelectric energy is a term usually reserved for large-scale hydroelectric dams. Examples are the Grand Coulee Dam in Washington State and the Akosombo Dam in Ghana. Micro hydro systems are hydroelectric power installations that typically produce up to 100 kW of power. They are often used in water rich areas as a Remote Area Power Supply (RAPS). There are many of these installations around the world, including several delivering around 50 kW in the Solomon Islands. Damless hydro systems derive kinetic energy from rivers and oceans without using a dam. Ocean energy describes all the technologies to harness energy from the ocean and the sea.

Marine current power, similar to tidal stream power, uses the kinetic energy of marine currents. Ocean thermal energy conversion (OTEC) uses the temperature difference between the warmer surface of the ocean and the colder lower recesses. To this end, it employs a cyclic heat engine. OTEC has not been field-tested on a large scale. Tidal power captures energy from the tides. Two different principles for generating energy from the tides are used at the moment.

Tidal motion in the vertical direction – Tides come in, raise water levels in a basin, and tides roll out. Around low tide, the water in the basin is discharged through a turbine, exploiting the stored potential energy. Tidal motion in the horizontal direction – or tidal stream power. Using tidal stream generators, like wind turbines but then in a tidal stream. Due to the high density of water, about eight-hundred times the density of air, tidal currents can have a lot of kinetic energy. Several commercial prototypes have been build, and more are in development.

Wave power uses the energy in waves. Wave power machines usually take the form of floating or neutrally buoyant structures which move relative to one another or to a fixed point. Wave power has now reached commercialization. Osmotic power or salinity gradient power, is the energy retrieved from the difference in the salt concentration between seawater and river water. Reverse electrodialysis (PRO) is in the research and testing phase. Vortex power is generated by placing obstacles in rivers in order to cause the formation of vortices which can then be tapped for energy. Deep lake water cooling, although not technically an energy generation method, can save a lot of energy in summer. It uses submerged pipes as a heat sink for climate control systems. Lake-bottom water is a year-round local constant of about 4°C.

Wave Farms Expansion

Portugal now has the world’s first commercial wave farm, the Agucadoura Wave Park, officially opened in September 2008. The farm uses three Pelamis P-750 machines generating 2.25 MW.Initial costs are put at 8.5 million. A second phase of the project is now planned to increase the installed capacity to 21MW using a further 25 Pelamis machines.

Funding for a wave farm in Scotland was announced in February, 2007 by the Scottish Government, at a cost of over 4 million pounds, as part of a £13 million funding packages for ocean power in Scotland. The farm will be the world’s largest with a capacity of 3MW generated by four Pelamis machines.

Hydroelectric Dams

The major advantage of hydroelectric systems is the elimination of the cost of fuel. Other advantages include longer life than fuel-fired generation, low operating costs, and the provision of facilities for water sports. Operation of pumped-storage plants improves the daily load factor of the generation system. Overall, hydroelectric power can be far less expensive than electricity generated from fossil fuels or nuclear energy, and areas with abundant hydroelectric power attract industry.

However, there are several major disadvantages of hydroelectric systems. These include: dislocation of people living where the reservoirs are planned, release of significant amounts of carbon dioxide at construction and flooding of the reservoir, disruption of aquatic ecosystems and birdlife, adverse impacts on the river environment, potential risks of sabotage and terrorism, and in rare cases catastrophic failure of the dam wall.

Hydroelectric power is now more difficult to site in developed nations because most major sites within these nations are either already being exploited or may be unavailable for other reasons such as environmental considerations

Wind Power An Alternative Energy

A wind turbine needs air, lots of it to turn the blades. A modern wind turbine ranges from 600 KW to 5 MW of rated power, although for commercial use the output range is typically 1.5-3 MW.

Because wind speed is not constant, a wind farm’s annual energy production is never as much as the sum of the generator nameplate ratings multiplied by the total hours in a year. The ratio of actual productivity in a year to this theoretical maximum is called the capacity factor. Typical capacity factors are 20-40%, with values at the upper end of the range in particularly favorable sites. For example, a 1 megawatt turbine with a capacity factor of 35% will not produce 8,760 megawatt-hours in a year, but only 0.35x24x365 = 3,066 MWh, averaging to 0.35 MW. Online data is available for some locations and the capacity factor can be calculated from the yearly output.

Globally, the long-term technical potential of wind energy is believed to be five times total current global energy production, or 40 times current electricity demand. This could require large amounts of land to be used for wind turbines, particularly in areas of higher wind resources. Offshore resources experience mean wind speeds of ~90% greater than that of land, so offshore resources could contribute substantially more energy. This number could also increase with higher altitude ground-based or airborne wind turbines.

Wind power is renewable and produces no greenhouse gases during operation, such as carbon dioxide and methane.

Wind Power Market

At the end of 2008, worldwide wind farm capacity was 120,791 megawatts (MW), representing an increase of 28.8 percent during the year, and wind power produced some 1.3% of global electricity consumption. Wind power accounts for approximately 19% of electricity use in Denmark, 9% in Spain and Portugal, and 6% in Germany and the Republic of Ireland. The United States is an important growth area and installed U.S. wind power capacity reached 25,170 MW at the end of 2008.

Horse Hollow Wind Energy Center, in Texas, is one of the world’s largest wind farm at 735.5 MW capacity. It consists of 291 GE Energy 1.5 MW wind turbines and 130 Siemens 2.3 MW wind turbines. A proposed 4,000 MW facility, called the Pampa Wind Project, is to be located near Pampa, Texas.

In the UK, a licence to build the world’s largest offshore windfarm, in the Thames estuary, has been granted. The London Array Windfarm, 20 km off Kent and Essex, should eventually consist of 341 turbines, occupying an area of 230 km². This is a £1.5 billion, 1,000 megawatt project, which will power one-third of London homes. The windfarm will produce an amount of energy that, if generated by conventional means, would result in 1.9 million tonnes of carbon dioxide emissions every year. It could also make up to 10% of the Government’s 2010 renewables target.

Wind Farms

Wind power is one of the most environmentally friendly sources of renewable energy

A wind farm, when installed on agricultural land, has one of the lowest environmental impacts of all energy sources:

* It occupies less land area per kilowatt-hour (kWh) of electricity generated than any other energy conversion system, apart from rooftop solar energy, and is compatible with grazing and crops.
* It generates the energy used in its construction in just 3 months of operation, yet its operational lifetime is 20 to 25 years.
* Greenhouse gas emissions and air pollution produced by its construction are low and declining. There are no emissions or pollution produced by its operation.
* In substituting for base-load coal power, wind power produces a net decrease in greenhouse gas emissions and air pollution, and a net increase in biodiversity.
* Modern wind turbines are almost silent and rotate so slowly (in terms of revolutions per minute) that they are rarely a hazard to birds.

Studies of birds and offshore wind farms in Europe have found that there are very few bird collisions. Several offshore wind sites in Europe have been in areas heavily used by seabirds. Improvements in wind turbine design, including a much slower rate of rotation of the blades and a smooth tower base instead of perchable lattice towers, have helped reduce bird mortality at wind farms around the world. However older smaller wind turbines may be hazardous to flying birds. Birds are severely impacted by fossil fuel energy; examples include birds dying from exposure to oil spills, habitat loss from acid rain and mountaintop removal coal mining, and mercury poisoning.

Wind Power A Viable Energy

Although initially is much cheaper to get hooked up to the local power company than it is to set up and hook into your own wind power system, in the long run you saves money by utilizing the wind for your energy needs while also becoming more independent. Not receiving an electric bill while enjoying the vantages of the modern electrically driven society is a marvelous feeling.

Electric bills and fuel bills are rising steadily, but the cost of wind power energy is low, and the cost of installing and hooking up a wind turbine is steadily coming down as demand rises and more commercial success is realized by various companies producing the turbines and researching technologies to make them ever more efficient.

Additionally, people are moving away from the conventional electric grids and the fossil fuels for personal reasons including desire for greater independence, the desire to live remotely or rurally without having to “go primitive’, governmental concerns such as fears of terrorist strikes on oil fields or power grids, and or concerns about the environment.

Once more, this need to get away from the conventional energy sources is the same one that drives people to look for the power of the wind for their energy need, giving added business opportunities to profit from wind turbine production and maintenance, which drives their costs down for the consumers.

In many provinces in Canada and states in the US where homeowners are allowed to sell their surplus energy back to the power company under what are called “net metering laws”. The rates that they are being paid by the local power companies for this energy are standard retail rates, put differently, the users are actually benefiting from their own energy production.

Some federal lawmakers are pushing to get the federal government to mandate these tax breaks and other wind power incentives. Japan and Germany already have national incentive programs in place.

Solar Energy Has Many Uses

Solar energy is the sunshine and the heat from the sun, is free and is infinite. All living matters on earth depends on it. Solar energy induce no air and water pollution, but there is still some impacts on the environment although indirect.

Photovoltaic cells (solar panels) used to convert sunlight into electricity uses silicon that also produce some waste materials. There are also large solar thermal farms and these farms can also be harmful to the environment and desert ecosystems if not properly managed.

Solar energy has many uses, for example, in agriculture. Greenhouses convert solar light to heat to enhancing the growth of plants and crops. Greenhouses has been around since the Roman times, today’s modern greenhouses were first built in Europe in 16th century. Greenhouses are still an important part of horticulture nowadays,

Daylight systems are being used in homes and businesses to maximize the energy released by the sun. It is used to provide interior illumination replacing the artificial lighting. Daylight systems include sawtooth roofs, light shelf, skylights, and light tube. Daylight systems when they are properly applied can cut down lighting-related energy consumption by as much as 25 percent.

Solar energy can also be formulated into solar thermal technologies which can be used for water heating, space heating, space cooling and process heat generation. Solar energy can also be used to distill water and make saline or brackish water potable or drinkable.

The solar water disinfection or SODIS involves exposing water-filled plastic polyethylene terephthalate or PET bottles. This process takes a long time, since the exposure time varies on the weather conditions. It requires at the least of six hours to two days during days with overcast conditions. Today, there are more than two million people in developing centuries use SODIS for their daily drinking water needs.

As well sunlight can be converted into electricity using photovoltaics or PV. PV has been mainly used to power small electronics like a calculator powered by a single solar cell to homes and businesses using solar panels. Using solar energy for water and space heating is the most widely use application of solar energy. While ventilation and solar air heating is also growing in popularity.

Solar cells, also called photovoltaic or photoelectric cells are use to convert sunlight directly into electricity. Also, solar furnaces use a huge array of mirrors to concentrate on the Sun’s energy into a small space and produced very high temperatures. Solar furnaces are also called “solar cookers”. A solar cooker can be used in hot countries to prepare food.

With all the benefits if using solar energy, there is still a downside for this alternative energy source. It does not work during night time. The cost of setting up solar systems is expensive, but the benefit of using solar energy when cumulated is so much more especially with decreasing prices as more users opting to use this source of renewable energy.

Teaching Children To Be Energy Efficient

Conserving energy and saving money ought be a family participation. Your children must also learn to contribute in cutting down the utility bills.

Teach children the importance of saving energy and the value of being energy efficient will help the planet earth. Tell them stories or read educational books about the importance of energy.

Lead by example because children tend to follow what elders do. Apply what you preach. Don’t simply tell them to turn the lights off before leaving their room; show them by always turning the lights off every time you leave a room. Teaching and leading by example are a good combination if you want to make good habits stick.

Provide informative materials for your kids to learn the value of preserving energy as well as the ways on how to save it. Computer software, educational sites, books and television shows that educate and entertain children would really make a difference on how well they will respond. This is especially relevant to children between 5 to 10 years old.

Household activities should not limit to eating, playing and entertainment. Chores can also be a good technique to bond with your children. Manually wash the car, water the plants, clean the table, wash the dishes, clean the house etc. These are some of the things you can do with your children while conserving energy.

A few energy saving tips for children.

1. Turn off the water while brushing your teeth.

2. Always turn off lights before leaving the room.

3. Turn the computer off when not in use.

4. Do not hold the refrigerator door open.

5. Unplug unnecessary appliance.

6. Use natural light whenever possible.

Saving energy should be just like any family activities you do, energy preservation should be fun, instructive and driven by good motive.

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