What is energy?

Energy resources from the Sun The energy in all these energy resources originated from the Sun. coal oil wind biomass natural gas food

Non-renewable energy resources Oil, coal and natural gas are examples of fossil fuels. They were formed from biological deposits over the course of millions of years. gas oil coal Photo credit: © 2008 Jupiterimages Corporation The amount of fossil fuel on Earth is limited. Once fossil fuels are used they cannot be replaced and will eventually run out, so they are called non-renewable.

Coal formation

Early stages of oil and gas formation Oil and gas are also biological in origin. Millions of years ago, tiny animals lived in the sea. Like today, their ecosystem was dependent on heat and light from the Sun and photosynthesis by plants. When they died, the animals fell into mud and sand at the bottom of the sea, but did not rot away. Over millions of years they were buried deeper by the mud and sand.

The Earth as a resource Objective; To investigate how oil is a finite resource and suggest solutions to reduce oil use and/or find replacement resources. Photo credit: © 2008 Jupiterimages Corporation

The Earth as a resource Peak oil / Finite and infinite -definitions Photo credit: © 2008 Jupiterimages Corporation

Later stages of oil and gas formation The temperature and pressure (caused by the weight of the sediments and deep burial) changed the mud and sand into rock, and the dead animals into crude oil and natural gas. The oil and gas is extracted from the seabed or under the ground, by drilling oil wells. Photo credit: © 2008 Jupiterimages Corporation Oil wells drilled at sea are supported by oil platforms.

Fossil fuels summary

Why are alternatives to fossil fuels needed? Burning fossil fuels has many bad effects on the environment. 50 100 150 200 250 300 Coal Oil Gas Years left However, environmental damage is not the only problem with continuing to rely on fossil fuels to supply our energy needs. What does this chart show? Governments and scientists are trying to develop alternative sources of energy to replace fossil fuel power stations.

What are renewable energy sources? Renewable energy resources will not run out because they can easily be generated anew. The photograph shows a dam built for the generation of hydroelectric power. Other examples of renewable energy resources are: wind power solar power tidal power biomass Photo credit: © 2008 Jupiterimages Corporation Only 4% of the UK’s energy comes from renewable sources. Why do you think this is?

How can the wind generate electricity?

How is solar energy used? There are a number of methods of generating electricity from the Sun’s energy. Passive solar heaters heat water directly using sunlight. Why are they black? Solar panels convert sunlight into electricity directly. They are used on some new houses and also on calculators. Photo credits: © 2008 Jupiterimages Corporation Mirrors can be used to focus sunlight onto pipes containing water. The hot water drives a generator.

Other renewable energy sources What other forms of renewable energy are there? Geothermal energy uses heat stored beneath the Earth’s surface to create steam. This is then used to power turbines. Biomass fuels are made of processed plant remains and are used in the same way as fossil fuels. More crops are grown to replace those used. Tidal currents can be used to generate electricity. The moving water is forced through turbines, which generate electricity. Waves can generate electricity by causing buoys to rise and fall. This kinetic energy is converted to electrical energy.

Other renewable energy sources

Renewable energy: summary Energy Resources Worksheet 2 accompanies this slide.

Energy sources for the future

Glossary biomass – Energy stored inside living or once-living materials such as wood. energy – The ability to do work. It exists in different forms such as chemical, electrical, heat and light. fission – The splitting of atoms, usually of uranium. Used to generate electricity in nuclear power stations. fossil fuel – A fuel such as coal, oil and gas that forms from animal and plant matter over millions of years. The world's supply of fossil fuels is running out fast. fuel cell – A device that reacts hydrogen with oxygen to produce water and electricity. fusion – The joining of atoms. These reactions power the Sun and could be used to generate electricity in the future. geothermal – Using the heat inside the earth to warm water or produce steam. greenhouse effect – The warming of the earth caused by greenhouse gases in the atmosphere trapping the Sun's energy. hydrogen – Fuel which can be used to power cars. The gas is converted to electricity and water by fuel cells. methane – Natural gas. It can be extracted from deep underground or produced by the decomposition of plant and animal remains. It is also produced in the guts of animals. nuclear energy – Energy stored inside atoms, which are the building blocks of everything around you. renewable – An energy resource that can be replaced and will not run out. solar energy – Energy obtained from the Sun.

Anagrams

Multiple-choice quiz