Tomorrow's energy

Natural sources of energy include sun, wind and water power, wood for fuel, power from the sea and heat from the ground. These are renewable types of energy source – they won’t run out. They are also clean and sustainable as they produce little greenhouse gases to produce electricity.

Pros and cons

You are going to find out what the advantages and disadvantages are for the different types of energy. It is unlikely that a single source of energy will ever be used to supply all our needs. A mix of sources will be used as it is today. Much energy is used to meet two types of demand:
Baseload is the level of electricity at must be supplied constantly to meet regular demand
Peak time is the extra amount that must be supplied to meet short-lasting increases in demand. Think of the amount of electricity required when everyone puts the kettle on at half-time when they’re watching the world cup football final!

So the energy supply must be:

• Reliable

• Safe and secure

• Low in cost

• Environmentally friendly

In groups, choose one of the following reports on each type of energy supply. Decide what are the advantages and disadvantages. Be prepared to answer questions from the rest of your class.

Biomass Report

Crops like wheat and sugar beat can be fermented to produce ethanol which can be burned to generate electricity or used to fuel vehicles.

Oils can come from plants like rapeseed.

Biodiesel and ethanol are already being used as fuel in vehicles.

It is carbon-neutral, the carbon dioxide produced when the fuels are burned is balanced by the carbon dioxide taken in when the plants grow.

Biomass is a renewable energy source, but is currently an expensive form of fuel. It also needs large areas of land to produce the crops and may have an impact on food supply and the environment.

It will only be able to supply a small proportion of the energy needs of the future.

Hydroelectric power Report

Hydroelectric power comes from flowing water. This can be in the form of a river, or man-made installation, for example, a dam.

Hydroelectric is a clean source of energy which does not generate emissions of carbon dioxide and because it does not use up the earth's fuel resources, it will not run out. It can also meet peak demands for electricity as the water flow can be controlled.

The construction of a dam can have a large impact on the environment - the valley above the dam must be flooded and anyone living there must be re-located.

There are only a limited number of places where hydroelectricity stations can be built and it will only be able to supply a small portion of the energy needed in the future.

Nuclear power Report

Nuclear energy currently provides nearly a quarter of the UK's electricity.

Most of the power stations will close over the next 20 years and there are no plans to build any new nuclear power plants.

Nuclear energy uses Uranium as a fuel to produce electricity.

Nuclear power stations only need refuelling every two years so they don’t depend on regular fuel deliveries to keep operating and there are hardly any carbon emissions.

Nuclear power plants have a good safety record with few accidents, but the consequences of an accident could be very serious. This is because of radioactive waste which needs to be kept very securely.

Nuclear plants can be very expensive to build, but the cost can remain stable because the costs of electricity generated from nuclear do not change greatly even if the cost of uranium goes up.

New research into the design and development of nuclear power is now ongoing so will we see a future of nuclear power stations?

Wind power Report

Wind power uses large propellers, called turbines to generate electricity as they are turned by the wind.

Currently there are 140 wind farms in the UK with 5 offshore.

Wind power is one of the safest of energy technologies and is renewable energy source.

Once built, they produce no carbon dioxide emissions.

They need to be built in open and windy areas and some people object to them because they spoil the countryside.

The UK is one of the windiest countries in Europe and there is great potential to produce at least a tenth of electricity from wind power by 2010.

Solar power Report

There are three ways that energy is produced from sunlight.

Solar cells convert sunlight directly into energy. These photovoltaic panels are currently very expensive.

Solar water heating uses the sun to heat water in rooftop glass panels. Water is pumped through pipes in the panels which are coloured black to keep the heat. In winter, the water has to be drained from the system to stop the panels from freezing.

Solar furnaces use large mirrors to focus the sun’s energy onto a small area, where it can produce very high temperatures. Solar power is clean and a renewable energy resource, but supply is not always reliable as it is available only during the hours of daylight. This means energy needs to be stored for use when it is not available.

Wave and tidal power Report

The UK has the best wave and tidal resource in Europe which has the potential to provide some of the UK’s energy in future years.

Some tidal plants work by capturing water in a pool as the tide comes in. The water is then released through a turbine as the tide goes out. Such schemes are similar to hydroelectric dams, but with the water coming from the action of the tides, not from rainwater or river flow.

Other tidal schemes are similar to wind farms; they have turbines mounted underwater and are driven by tidal movement.

Power is supplied when the tide is flowing which only happens for around 10 hours each day. It doesn’t produce carbon dioxide emissions and is a renewable source of energy.

Technology is still at the experimental stage and more development is needed. It may also be expensive to build and maintain and may not be enough to meet baseload demands for electricity.

Future fuel

Write your own one page review based on what you have heard from the different groups. Include:

• a paragraph about each of the alternative energy sources of the future

• one advantage and one disadvantage for each energy supply which you think is the most important

• a conclusion where you decide which energy options will be the most likely in the future

Read more case studies:

For a list of more links on energy sources, visit It’s only Natural – Renewable Energy for Schools from the Department for Trade and Industry.