Energy Resources

Energy Resources Noadswood Science, 2011

Energy Resources • To know what energy resources are available, and the pros and cons of these

Energy • Why are the two types of energy resource? • Non-renewable energyresources - once they have all been used up they cannot be replaced • Renewable energy resources can be replaced, never running out

Energy • Energy allows things to happen, but it cannot be created or destroyed - it can only be stored or transferred • Energy can be transferred from many different resources - in non-renewable resources such as fossil fuels, energy is stored chemically in the fuel, and burning them releases this energy • Energy can also be transferred from renewable resources, such as solar cells, where energy is absorbed from sunlight and turned into electricity

Energy • What are the non-renewable and renewable energy sources? • Non-renewable: - • Fossil fuels (coal, oil, natural gas) • Nuclear • Renewable: - • Solar • Tidal • Wave • Hydro-electric (HEP) • Geothermal • Wind • Biomass

Energy • Complete the sheet for the advantages / disadvantages of energy resources as we go through them…

Fossil Fuels - Advantages • Non-renewable energyresources - once they have all been used up they cannot be replaced • Fossil fuels- these are coal, oil and natural gas which release heat energy when they are burned. They are fossil fuels because they were formed from the remains of living organisms millions of years ago • About three-quarters of the electricity generated in the UK comes from power stations fuelled by fossil fuels

Fossil Fuels - Disadvantages • Non-renewable energyresources - once they have all been used up they cannot be replaced • Fossil fuels- these are non-renewable so they will eventually run out. They also release CO2 when they burn, contributing to the greenhouse effect (increasing global warming) • Of the three fossil fuels, for a given amount of energy released, coal produces the most carbon dioxide and natural gas produces the least • Coal and oil release sulfur dioxide gas when they burn, which causes breathing problems for living creatures and contributes to acid rain

Nuclear - Advantages • Non-renewable energyresources - once they have all been used up they cannot be replaced • Fossil fuels- these are mainly the radioactive metals uranium and plutonium. Nuclear fuels are not burnt to release energy – instead the fuels are involved with nuclear reactions within a nuclear reactor which releases heat • The rest of the process of generating electricity is then identical to the process using fossil fuels – heat energy boils water which turns into steam • The steam turns turbines which drive generators to produce electricity • Unlike fossil fuels no carbon dioxide or sulphur dioxide is produced

Nuclear - Disadvantages • Non-renewable energyresources - once they have all been used up they cannot be replaced • Fossil fuels- these are non-renewable and if there is an accident large amounts of radioactive material could be released into the environment • Nuclear waste remains radioactive and is hazardous to health for thousands of years - it must be stored safely which can be very expensive

Wind - Advantages • Renewable energy resources can be replaced, never running out • Wind power- windis caused by huge convection currents in the Earth's atmosphere, driven by heat energy from the Sun. The moving air has huge amounts of kinetic energy, and this can be transferred into electrical energy using wind turbines • Wind turbines have blades mounted on a tower which are connected to gears linked to a generator – as the wind blows it transfers some of its kinetic energy to the blades • There are no fuel costs, and no polluting gasses are produced

Wind - Disadvantages • Renewable energy resources can be replaced, never running out • Wind power- wind farms are noisy and may spoil the view for people living near them • The amount of electricity generated depends on the strength of the wind – if there is no wind, there is no electricity

Water Energy - Advantages • Renewable energy resources can be replaced, never running out • Water power- moving water has kinetic energy: • Wave machines use the up and down movement of waves to turn electricity generators • Tidal barrages are built across the mouths of rivers. As water moves in or out of the river mouth when the tide turns, the kinetic energy in the water is used to turn electricity generators • Hydroelectric power (HEP) schemes store water high up in dams (the water has stored gravitational potential energy). As the water rushes through pipes, this stored energy is transferred to kinetic energy, which turns electricity generators

Water Energy - Advantages • Renewable energy resources can be replaced, never running out • Water power - in its various forms has no fuel costs and no harmful polluting gases are produced • Tidal barrages and hydroelectric power stations are very reliable and can be turned on quickly

Water Energy - Disadvantages • Renewable energy resources can be replaced, never running out • It has been difficult to scale up the designs for wave machines to produce large amounts of electricity • Tidal barrages destroy the habitat of estuary species, including wading birds • Hydroelectricity dams flood farmland and push people from their homes - the rotting vegetation underwater releases methane, which is a greenhouse gas

Biomass - Advantages • Renewable energy resources can be replaced, never running out • Biomass - these are fuels from living things such as trees • As long as we continue to plant new trees to replace those cut down, we will always have wood to burn. Just as with the fossil fuels, the energy stored in biomass fuels ultimately came from the Sun

Biomass - Disadvantages • Renewable energy resources can be replaced, never running out • Biomass – burning produces gasses which contribute to global warming

Geothermal - Advantages • Renewable energy resources can be replaced, never running out • Several types of rock contain radioactive substances such as uranium – radioactive decay of these substances releases heat energy, warming the rocks • In volcanic areas the rocks may heat water so that it rises to the surface naturally as hot water and steam (driving turbines and generators) • In some areas the rocks are hot, but no hot water as steam rises to the surface – in this situation deep wells are dug and cold water pumped down them where the water runs through fractures in the rocks, and is heated up, returning to the surface as hot water and steam…

Geothermal - Advantages • Renewable energy resources can be replaced, never running out • There are no fuel costs, and no polluting gasses are produced

Geothermal - Disadvantages • Renewable energy resources can be replaced, never running out • Most parts of the world do not have suitable areas where geothermal energy can be exploited

Solar- Advantages • Renewable energy resources can be replaced, never running out • Solar cells generate electric currents directly from sunlight • Solar panels simply contain water pipes which utilise heat radiation from the Sun which is absorbed by a black surface under the water pipe which gets hot, heating the water • Solar furnaces are large arrays of curved mirrors which focus onto one spot to produce very high temperatures changing water into steam to drive turbines

Solar- Advantages • Renewable energy resources can be replaced, never running out • Solar cells are devices that convert light energy directly into electrical energy • Solar panels do not generate electricity, but heat up water • Cold water is pumped up to the solar panel, heating up until it is transferred to a storage tank • A pump pushes cold water from the storage tank through pipes in the solar panel - the water is heated by heat energy from the sun and returns to the tank

Solar- Advantages • Renewable energy resources can be replaced, never running out • There are no fuel costs, and no polluting gasses are produced

Solar- Disadvantages • Renewable energy resources can be replaced, never running out • Solar cells are expensive and inefficient, so the cost of their electricity is high • Solar panels may only produce very hot water in very sunny climates, and in cooler areas may need to be supplemented with a conventional boiler • Although warm water can be produced even on cloudy days, neither solar cells nor solar panels work at night

Renewable &Non-renewable Energy Resources

Design • We need to get a lot of energy, but how we get this can vary (between non-renewable and renewable resources) • Your task is to power a house that is on a remote island (as efficiently and as environmentally friendly as possible – using as many renewable energy resources as possible) • Your house will need power for everything a house in the developed world does (i.e. heating; lights; kitchen appliances; televisions etc…) • Design your house, labeling your energy resource and how your house can utilise this energy…

Energy Resources