P1-Energy Flashcards

Question

How can the efficiency for any energy transfer for power be worked out?

Answer 1

Efficiency= useful power output / total power input

Answer 2

No device is 100% efficient and the wasted energy is usually transferred to useless thermal energy stores Electric heaters are the exception to this. They are usually 100% efficient because all the energy in the electrostatic energy store is transferred to useful thermal energy stores Ultimately all energy ends up transferred to thermal energy stores.

Answer 3

Non-renewable energy resources are fossil fuels and nuclear fuel. Fossil fuels are natural resources that form underground over millions of years. They are typically burnt to provide energy. The three main fossil fuels are: 1)coal 2)oil 3)natural gas They will all run out one day. They all do damage to the environment. But they provide most of our energy

Answer 4

Renewable energy sources are: 1) The sun (solar) 2) wind 3) water waves 4) hydro-electricity 5) Bio-fuel 6) Tides 7) geothermal These will never run out as the energy can be renewed as it is used Most of them do damage the environment, but in less nasty ways than non-renewables The trouble is they don't provide much energy and some of them are unreliable as they are dependant on the weather

Answer 5

Transport is one of the most obvious ways where fuel is used. Transportation methods that use either renewable or nonrenewable energy resources: Non renewable eneegy resources: petrol and diesel powered vehicles use fuel created from oil. Call is used in some old-fashioned steam trains to boil water to produce steam Renewable energy resources: vehicles that run on pure biofuels or a mix of a biofuel and petrol or diesel

Answer 6

Wind power involves lots of wind turbines up in exposed places like on moors or round coasts. Each turbine has a generator inside it, the rotating blades turn the generator and produce electricity. There's no pollution. There are no fuel costs and there are minimal running costs. There's also no permanent damage to the landscape, as if you remove the turbines, you remove the noise and the view returns to normal. They do spoil the view. You need about 1500 win turbines to replace one coal-fired power station and 1500 of them cover a lot of ground which would have a big affect on the scenery. They can be very noisy which can be annoying for the people living nearby. There is also the problem of the turbines stopping when the wind stops or if the wind is too strong and it's impossible to increase supply when there is extra demand. On average win turbines produce electricity 70% to 85% of the time. The initial costs are also quite high.

Answer 7

Solar cells generate electric currents directly from sunlight. Solar cells are often the best source of energy to charge batteries in calculators and watches which don't require much electricity. Solar power is often used in remote places where there is not much choice and to power electric road signs and satellites. There's no pollution. In sunny countries solar power is a very reliable source of energy. Solar power can still be cost-effective even in cloudy countries like Britain though. Running costs are almost nil. Solar cells are usually used to generate electricity on a relatively small scale. They are only effective in daytime and to places where there is little sun, quite useless. You cannot increase the power output when there is extra demand. Initial costs are high. Used on a small scale.

Answer 8

This is possible in volcanic areas or where hot rocks lie quite near to the surface. The source of much of the energy is the slow decay of various radioactive elements, including uranium, deep inside the earth. It is free energy that is reliable and does very little damage to the environment. Geothermal power can be used to generate electricity or to heat buildings directly. The main drawbacks with geothermal power of that there aren't very many suitable locations for power plants and that the cost of building a power plant is often high compare to the amount of energy it produces

Answer 9

Hydro-electric power usually requires the flooding of a valley by building a big dam. Water is allowed out through turbines. There is no pollution. It can provide an immediate response to an increased demand for electricity. There's no problem with reliability. No fuel costs and minimal running costs. Useful way to generate electricity on a small scale in remote areas. There is a huge impact on the environment due to the flooding of the valley (rotting vegetation releases methane and Co2) and possible loss pf habitat for some species (sometimes the loss of whole villages). The reservoirs can also look very unsightly when they dry up. Putting hydroelectric power stations in remote valleys tends to reduce their impact on humans

Answer 10

Wave power involves lots of small wave powered turbines located around the coast. The moving turbines are connected to a generator. There is no pollution, no fuel costs and minimal running costs.Very useful on small islands They disturb the seabed and the habitats of marine animals, spoiling the view and being a hazard to boats. They are fairly unreliable since waves tend to die put when the wind drops. Initial costs are high. Wave power is never likely to provide energy on a large scale

Answer 11

Tides are used in lots of ways to generate electricity. The most common method is building a tidal barrage. Tidal barrages are big dams built across river estuaries, with turbines in them. As the tide comes in it fills the estuary. The water is then allowed out through turbines at a controlled speed. Tides are produced by the gravitational pull of the Sun and Moon. There is no pollution. They are mostly reliable as they happen twice a day without fail. No fuel costs and minimal running costs The height of the tide is variable so lower tides will provide significantly less energy than the bigger spring tides. They also don't work when the water level is the same either side of the barage this happens four times a day because of the tides. They prevent free access by boats, spoiling the view and altering the habitat of the wildlife. Initial costs are moderately high

Answer 12

Bio-fuels are renewable energy sources created from either plant products or animal dung. They can be solid, liquid or gas and can be burnt to produce electricity or run cars in the same way as fossil fuels. They are supposedly carbon neutral, although there is some debate about this as it's only really true if you keep growing plants at the rate that you're burning things. Biofuels are fairly reliable as crops take a relatively short time to grow and different crops can be grown all year round. However they cannot respond to immediate energy demands. To combat this, biofuels are continuously produced and stored for when they're needed. The cost to refine biofuels is very high and some worry that grow crops specifically for biofuels will mean there isn't enough space or water to meet the demands for crops that are grown for food. In some regions large areas of forest have been cleared to make room to grow biofuels, resulting in lots of species losing their natural habitat. Did UK and burning of this vegetation also increases CO2 and methane emissions.

Answer 13

Fossil fuels and nuclear energy are reliable. There is enough fossil a nuclear fuels to meet current demand and they are extracted from the Earth to fast enough rate that power plants always have fuel in stock. This means that the power plants can respond quickly to changes in demand. However, these fuels are slowly running out. It's no new resources are found, some fossil fuel stocks will run out within 100 years While the set up costs of power plants can be quite high compare to some of the energy resources, the running costs aren't that expensive. Combined with very low fuel extraction costs, using fossil fuels is a cost-effective way to produce energy.

Answer 14

Cole,oil and gas release CO2 into the atmosphere when they are burned. All the CO2 adds to the greenhouse effect and contributes to global warming. Burning coal and oil also releases sulphur dioxide which causes acid rain which can be harmful for the trees and soils and can have far reaching effects in ecosystems Acid rain can be reduced by taking the sulphur out before the fuel is burned, or cleaning up. Coal mining makes a mess of the landscape, especially open cast mining. As with many energy resources, the view can be spoilt by fossil fuel power plants. Oil spillages cause serious environmental problems, affecting mammals and birds that live in and around the sea. Nuclear power is clean but the nuclear waste is very dangerous and difficult to dispose of Nuclear fuel is relatively cheap but the overall cost of nuclear power is high due to the cost of the powerplant and final decommissioning Nuclear power plants always carry the risk of major catastrophe

Answer 15

Over the 20th century, the electricity use of the UK hugely increased as the population grew and people began to use electricity for more and more things. Since the beginning of the 21st-century, electricity used in the UK has been decreasing as we get better making appliances more efficient and become more careful with energy use in our homes. Most of our electricity is produced using fossil fuels and from nuclear power. Generating electricity isn't the only reason we burn fossil feels as oil is used to fuel cars and gas is used to heat homes and cook food. However we are trying to increase our use of renewable energy resources to use renewable resources to provide 50% of its total yearly energy by 2020 this moves towards renewable energy resources has been triggered by many things.

Answer 16

People are aware of the damaging effects Burning fossil fuels has on the environment. This makes many people want to use more renewable energy resources that affect the environment less. People and governments are also becoming increasingly aware that non-renewable energy is running out. Many people think it's better to learn to get by without non-renewables before this happens. Pressure from other countries and the public has meant that governments have begun to introduce targets using renewable resources this intern puts pressure on energy providers to build new power plants that use renewable resources to make sure they do not lose business money. Car companies have also been affected by this change in attitude towards environment. Electric cars and hybrids are already on the market and their popularity is increasing.

Answer 17

There is a lot of scientific evidence supporting renewables but although scientist can give advice they don't have the power to make people companies or governments change their behaviour. Building new renewable power plants cost money so some energy providers are reluctant to do this especially when fossil fuels are so cost-effective. The cost of switching to renewable power will have to be paid either by customers in their bills or through government and taxes. Some people don't want to or can't afford to pay and their arguments about whether it's ethical to make them. Even if new power plants are built their are arguments about where to put them. There are arguments over whether is ethical to make people put up with windfarms built next to them and they may not agree with the reasons for their use. Some energy resources like Windpower or not as reliable as traditional fossil feels whilst others cannot increase their power output on demand. This would mean either having to use a combination of different power plants or researching ways to improve reliability. Research on improving the reliability and cost of renewables takes time and money, it may be years before improvements are made even with funding. Until then we need dependable non-renewable power. Making personal changes can also be quite expensive. Hybrid cars are generally more expensive than equivalent to petrol cars and things like solar panels your home are still quite pricey the cost of these things is slowing down but they are still not an option for many people.