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Subject: Music

This US group was formed in Los Angeles, California, in 1978 by Steve Allen (guitar, vocals) and Ron Flynt (bass, vocals), two expatriate musicians from Tulsa, Oklahoma. Drummer Mike Gallo ...

penetration

penetration   Quick reference

A Dictionary of Energy Science

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Subject Reference
Current Version:
2017

...penetration The fraction or percentage of the total market that is taken by a product. For example, wind would have a penetration of 20 per cent when wind farms generated 20 per cent of the total power on a grid...

capacity credit

capacity credit   Quick reference

A Dictionary of Energy Science

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Subject Reference
Current Version:
2017

...of generating output at critical times. For example, in systems with winter evening peak demand, the photovoltaic capacity would not constitute capacity credit. For wind, rough values are 30 per cent of the new installed wind capacity at 10 per cent penetration and 20 per cent at 20 per cent penetration. Diverse portfolios offer greater capacity credit, due to their increased probability of...

process heating

process heating   Quick reference

A Dictionary of Energy Science

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Subject Reference
Current Version:
2017

...process heating The use of heat in the production of materials. Process heat is used in many areas of manufacturing and accounts for ~20 per cent of all industrial energy use. Examples are pasteurization of food, injection moulding, sterilization, and drying of products. Ensuring good efficiency, for example by preheating combustion air and implementing effective heat recovery, is important for minimizing energy...

solar farm

solar farm   Quick reference

A Dictionary of Energy Science

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Current Version:
2017

...to generate electricity for a grid . A recent example ( 2013 ) is the California Valley 250 MW capacity solar farm in California, which has a capacity factor of 25 per cent. The panels, made up of 20 per cent efficient silicon solar cells , are mounted on a single-axis tracking system, which increases the output relative to a fixed orientation by about 20 per cent. It covers an area of 796 ha, giving a power density of about 8 MW/km 2 . There are now several 500 MW plus capacity farms in the world. The market share of solar farms is set to increase, as...

wind variability

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A Dictionary of Energy Science

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Current Version:
2017

...occurs at any site. While the speed of a wind does not stay the same, state-of-the-art wind forecasts can now predict the timing and strength of the wind to a considerable degree of accuracy twenty-four hours in advance. When the penetration of wind power is less than about 20 per cent, its variability can be accommodated in the same way as demand variations, by turning on or off spinning reserve . For higher penetrations, smart grids , larger grids , and energy storage can be...

Three Mile Island accident

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A Dictionary of Energy Science

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Current Version:
2017

...Three Mile Island accident A loss-of-cooling accident (LOCA) in 1979 in a pressurized water reactor at Three Mile Island in Pennsylvania, USA, caused by both mechanical and human failure, resulting in a 20 per cent core meltdown. The outer containment building contained nearly the entire radioactivity released. However, the costs of the clean-up were enormous, almost $1 billion, and the loss of public confidence in nuclear power , particularly in the USA, was...

Drake, Edwin

Drake, Edwin (1819–80)   Quick reference

A Dictionary of Energy Science

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Current Version:
2017

...Drake, Edwin ( 1819–80 ) An American former railwayman who initiated the modern oil industry by devising a method of protecting a drill hole by installing a tube (drive pipe) down to bedrock. In 1859 in Pennsylvania he struck oil at a depth of 21 m and had a yield of 20–40 barrels a day. But he did not patent his invention and failed to make money. (Oil had been used in relatively small quantities for millennia before in China, Arabia, and Central Asia, for...

ocean thermal energy conversion

ocean thermal energy conversion   Quick reference

A Dictionary of Energy Science

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Current Version:
2017

...ocean thermal energy conversion ( OTEC ) The exploitation of the higher temperature (20–25 ° C) in the top 100 m of an ocean (arising from the absorption of solar radiation) than that which occurs deep below the surface, to drive a heat engine to generate electricity. This small temperature difference, however, results in low thermal efficiencies. There are also significant technical challenges in manufacturing the long large-diameter pipes needed and very efficient heat exchangers cost-effectively, and to date the process is not generally economically...

solar cell

solar cell   Quick reference

A Dictionary of Energy Science

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Subject Reference
Current Version:
2017
Subject:
Science and technology, Engineering and Technology, Environmental Science
Length:
205 words
Illustration(s):
1

...the series resistance and the back surface recombination, respectively, of the cell. The band gap in silicon (1.1 eV) determines the maximum efficiency and the open-circuit voltage V OC . Good commercial silicon cells have V OC ~0.7 V and 20 per cent of the solar energy is converted to electrical energy, i.e. a 20 per cent efficient cell. See also multijunction solar cell ; photovoltaics ; schockley-queisser limit . Silicon solar...

land-use change

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A Dictionary of Energy Science

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Current Version:
2017

...bound up in the soil; the increased aeration of the soil speeds up the decomposition of organic matter with the emission of carbon dioxide . The time to replace the CO 2 liberated by converting non-degraded land to biofuel production is about 50 years for growing corn (USA), 20 years for sugar cane (Brazil), 50 years for rapeseed (EU), and 100 years for palm trees. On the other hand, for degraded land there is very little release of CO 2 when preparing it for growing suitable plants, such as cassava, jatropha, or switchgrass. See also conservation...

wind power

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A Dictionary of Energy Science

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Current Version:
2017

...3 per cent of the global electricity demand of ~22400 TWh. The cost per kWh from the best onshore wind sites is now competitive with that from fossil fuel plants, while from offshore sites it is roughly twice as expensive. The global onshore resource is estimated to be about 20 TW. See also wind farm...

Stern report

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A Dictionary of Energy Science

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Current Version:
2017

...climate change , whose principal conclusion was that the benefits of strong, early international action on climate change would outweigh the global costs. By spending ~1 per cent of gross domestic product annually by 2050 on mitigation , a reduction in welfare equivalent to ~5–20 per cent reduction in consumption per head under a business as usual scenario would be avoided. It emphasized that the scientific evidence pointed to the increasing risks of serious impacts from climate change if no action was taken, and that the poorest countries will suffer...

carbon intensity

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A Dictionary of Energy Science

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Current Version:
2017

...When applied to power stations, the carbon intensity is the amount of emissions per unit of electricity generated. Typical values, in units of kg CO 2 -eq/MWh e , are: coal-fired ~1000; gas-fired ( combined cycle gas turbine ) ~500; solar photovoltaic farm ~50; onshore wind farm ~20. When applied to a country, the carbon intensity is the amount of emissions per unit of gross domestic product . The carbon intensity is also called the emissions factor , emissions intensity , or carbon efficiency...

Fukushima accident

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A Dictionary of Energy Science

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2017

...series of tsunamis breached the protective sea wall around the reactors, and the emergency power and cooling were lost. A large amount of radioactivity , about a tenth of that released in the Chernobyl accident , was emitted, which led to an evacuation of all people living within 20 km of the plant. Although the increased risk of death by cancer, compared with that from other causes, in areas contaminated by the radioactivity was estimated to be very small (~0.1 per cent as against 27 per cent), global confidence in nuclear power was significantly dented by...

photovoltaics

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A Dictionary of Energy Science

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Current Version:
2017

...MW per km 2 and capacity factors of now typically ~0.2. Installed global capacity increased in 2014 by 29 per cent to 180 GW, which provided ~1 per cent of the global electricity demand of ~22400 TWh. The average learning rate over the last 34 years has been close to 20 per cent, but in the period 2010–14 it was about 40 per cent with a PV module price dropping by a factor of 4. The cost for a typical 10–100 kWp PV rooftop system in Germany at the end of 2014 was ~€1,300/kWp. The cost per kWh in several sunny regions is now competitive with...

lead-acid battery

lead-acid battery   Quick reference

A Dictionary of Energy Science

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Subject Reference
Current Version:
2017
Subject:
Science and technology, Engineering and Technology, Environmental Science
Length:
181 words
Illustration(s):
4

...oxidizes to lead sulphate by the reaction Pb + H 2 SO 4 → PbSO 4 + 2 H + + 2 e − , and the lead oxide cathode reduces to lead sulphate by the reaction PbO 2 + 2 H + + 2 e − + H 2 SO 4 → PbSO 4 + 2 H 2 O . The overall reaction is Pb + PbO 2 + H 2 SO 4 → 2 PbSO 4 + 2 H 2 O + ~ 2.0 V . Lead-acid...

biomass

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A Dictionary of Energy Science

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Current Version:
2017

...corn, straw, logs, dung, and crop residues that are used either directly or indirectly to produce heat, electricity, or fuels ( biofuels ). The burning of biomass provides about 10 per cent of the world’s energy requirements. Biomass production per unit area per year is typically ~20 t/ha/y, corresponding to ~1 MWth/km 2 , which necessitates large areas of land for significant power production (NB: algae biofuels can have a significantly higher yield). As a source of energy, it is potentially low-carbon, since the carbon dioxide released on combustion was...

thermoelectric generator

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A Dictionary of Energy Science

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Current Version:
2017

...given by η = η Carnot [ ( F − 1 ) / ( F + T h / T c ) ] , where F = ( 1 + Z T ave ) , T h , T c , and T ave are the hot and cold surface temperatures and average temperature respectively, and η Carnot = ( T h − T c ) / T h is the Carnot efficiency. Typically, efficiencies of 20 per cent of η Carnot can be obtained. A good material for temperature differences of around 100 ° C is bismuth telluride, which has a ZT of ~1. TEGs can be used to generate electricity from waste heat and in space...

nuclear reactor

nuclear reactor   Quick reference

A Dictionary of Energy Science

Reference type:
Subject Reference
Current Version:
2017
Subject:
Science and technology, Engineering and Technology, Environmental Science
Length:
202 words
Illustration(s):
1

...state termed critical . In case the pressure vessel ruptures, the reactor is surrounded by a containment building. The energy released in each fission is ~200 MeV (as compared with a few eV in chemical reactions), and means that one tonne of natural uranium is equivalent to about 20,000 tonnes of coal. A typical reactor output power is ~1 GW. See also modular nuclear reactor ; nuclear power . Pressurized water reactor (PWR) ...

radiative forcing

radiative forcing   Quick reference

A Dictionary of Energy Science

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Current Version:
2017

...heating (or cooling) of either warms (or cools) both together. The Intergovernmental Panel on Climate Change estimates the radiative forcings relative to pre-industrial conditions ( 1750 ). The troposphere contains ~80 per cent of the mass of the atmosphere and is typically about 20 km deep near the equator and 10 km near the poles. The radiative forcing for 2011 from the increase in CO 2 concentration is estimated to be in the range 1.4 to 2.2 W/m 2 , from the effect of atmospheric aerosols 0 to −2 W/m 2 , and the total is estimated to be 1.1–3.3 W/m 2 ....

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