Geothermal Energy | Geothermal Energy Questions?
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Geothermal Energy | Geothermal Energy Questions?

How is the energy gathered and/or created?How is the energy stored for later use?Currently, what is keeping this form of energy from widespread use? Or why is it used for widespread use?When is the energy/resource expected to be easily accesible to the general public?

Geothermal energy is harnessed by drilling down in areas where magma is close to the surface such as near a volcano or hotsprings. Water is then injected into the hole and the heat from the magma makes it boil. The pressure from the resulting steam is used to spin turbines which produces electricity. Normally the electricity is immediately used to power houses, buildings etc, but i suppose if you wanted to store it you could use a large array of battries. Geothermal energy is not in widespread use because it only works in areas where there is magma close to the earths surface and there arent many areas like that. The energy may never be easily accessible by the public for the reason just stated.

I can answer you referring to its use in house heating. You can heat a house by using the geothermal gradient, which varies depending on where you are, but in some places you just have to make a drillhole, and then pump cold water inside; the water will get warm, and then you extract it, being useful for heating. This energy can’t be stored though.

This is currently expensive, so yo have to invest a lot of money when you build a new house in order to use geothermal energy, and it is not worthwhile everywhere, as the geothermal gradient varies from place to place, and in some places you can over exploit the aquifer, making useless.

Here in Spain it is a new technology, being used in some places, and there is still a lot to be learned about it, but little by little it is becoming increasingly used. And they say that every IKEA store gets all of its energy from geothermal sources…


Environmental impact

Krafla Geothermal Station in northeast Iceland

Fluids drawn from the deep earth carry a mixture of gases, notably carbon dioxide (CO2), hydrogen sulfide (H2S), methane (CH4), and ammonia (NH3). These pollutants contribute to global warming, acid rain, and noxious smells if released. Existing geothermal electric plants emit an average of 400 kg of CO2 per megawatt-hour (MWh) of electricity, a small fraction of the emission intensity of conventional fossil fuel plants.[5] Plants that experience high levels of acids and volatile chemicals are usually equipped with emission-control systems to reduce the exhaust. Geothermal plants could theoretically inject these gases back into the earth, as a form of carbon capture and storage.

In addition to dissolved gases, hot water from geothermal sources may hold in solution trace amounts of toxic chemicals, such as mercury, arsenic, boron, antimony, and salt.[30] These chemicals come out of solution as the water cools, and can cause environmental damage if released. The modern practice of injecting geothermal fluids back into the Earth to stimulate production has the side benefit of reducing this environmental risk.

Plant construction can adversely affect land stability. Subsidence has occurred in the Wairakei field in New Zealand.[31] Enhanced geothermal systems can trigger earthquakes as part of hydraulic fracturing. The project in Basel, Switzerland was suspended because more than 10,000 seismic events measuring up to 3.4 on the Richter Scale occurred over the first 6 days of water injection.[32] The risk of geothermal drilling leading to uplift has been experienced in Staufen im Breisgau.

Geothermal has minimal land and freshwater requirements. Geothermal plants use 404 square meters per GWh versus 3,632 and 1,335 square kilometres for coal facilities and wind farms respectively.[31] They use 20 litres of freshwater per MWh versus over 1000 litres per MWh for nuclear, coal, or oil

Economics

Geothermal power requires no fuel, it is therefore immune to fuel cost fluctuations. However, capital costs tend to be high. Drilling accounts for over half the costs, and exploration of deep resources entails significant risks. A typical well doublet in Nevada can support 4.5 megawatt (MW) of electricity generation and costs about $10 million to drill, with a 20% failure rate.[19] In total, electrical plant construction and well drilling cost about 2-5 million per MW of electrical capacity, while the levelised energy cost is 0.04-0.10 per kWh.[6] Enhanced geothermal systems tend to be on the high side of these ranges, with capital costs above $4 million per MW and levelized costs above $0.054 per kWh in 2007.[33]

Geothermal power is highly scalable: a small power plant can supply a rural village, though capital can be high.[34]

Chevron Corporation is the world’s largest private producer of geothermal electricity.[35] The most developed geothermal field is the Geysers in California. In 2008, this field supported 15 plants, all owned by Calpine, with a total generating capacity of 725 MW. Renewable energy. Energy accesible to the public:

Biofuel

Biomass

Geothermal

Hydroelectricity

Solar energy

Tidal power

Wave power

Wind power

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