Energy resources

• Geothermal energy is heat energy that is stored beneath the Earth's surface and can be used for heating and electricity generation.
• Wind energy is a renewable energy source that uses wind to generate electricity.
• Wind energy creates noise and visual pollution. It is expensive to install and maintain. It is unreliable because no wind means no electricity.
• Wind energy is generated from the kinetic energy of the wind rotating the blades. This turns a generator inside, which produces electricity.
• Wave power is the energy of waves and is generated when the floating generator is moved up and down from the waves. This motion turns a generator, which produces electricity.
• Wave power creates visual pollution because cables link the generators directly to the national grid, which also ruins coast lines, and can be dangerous to wildlife.
• Wave power is unreliable (inefficient) because it doesn't produce a constant supply of energy.
• Hydroelectric power is a renewable energy source. It is generated by the movement of water through a dam. However, it creates visual pollution, has a high start up cost, can change natural wildlife habitats and few places have the right height and rainfall for the dam.
• In hydroelectric power, the kinetic energy from the movement of the water behind the dam causes turbines to rotate, which generates electricity.
• Tidal energy is the energy from tides. It traps water behind a barrier (barrage) and is released to the other side through a small tunnel in the barrier. The water flow spins a turbine in this tunnel which drives a generator to create electricity.
• Tidal energy has a high start up cost, creates visual pollution and stops boats and wildlife moving freely in the sea.
• Geothermal energy is a renewable energy source that does not produce greenhouse gas emissions during operation, making it environmentally friendly.
• Geothermal energy requires simple technology but it can be expensive to set up, can only be used in certain places and there is limited expertise (people who can install it).
• In a fossil-fueled power station, coal is burned to heat water in a boiler, which produces steam. The steam turns a turbine to generate electricity.
• Biofuels are made from biological sources, like decomposing waste or plants.
• Solar cells can be good for remote homes that aren't connected to the national grid. They are renewable and have low maintenance. However, they are very expensive, are inefficient without many and need light to work.
• Nuclear power is generated when the nucleus of uranium splits in to two. This happens in the core of the reactor. Since there are lots of uranium atoms in one place, when they split, the core becomes very hot. A liquid (coolant) leaves the core very hot and flows through a pipe to a heat exchanger. The thermal energy transferred by the coolant turns water into steam in the heat exchanger and the steam drives a turbine, which generates electricity.
• Nuclear power is non-renewable but does not produce carbon dioxide. It also produces a lot of waste that has to be stored for many years and safety is a concern. However, it is very efficient and produces more energy per kg then fossil fuels.