Renewable Energy

As fossil fuels and nuclear fuels are non-renewable energy resources -> they are being used quicker than they can be replaced; they are finite resources, we need to look for alternative energy resources before they run out.

Renewable energy can be replenished as it is being used.

Renewable energy resources are:

• Wind

• Biofuel

• Solar

• Geothermal

• Hydroelectritcity

• Tides

• Water Waves

Wind

Wind is used to rotate large blades on wind turbines, which in turn drive a generator to produce electricity. The UK uses wind turbines to supply electricity to the national grid and thus to all our homes. Wind is a renewable energy resource because it can be replaced as it is being used; we only need to wait until the next windy day, which is frequent in the UK. A significant advantage of wind turbines over fossil fuels is that they do not release greenhouse gases into the atmosphere. However, a disadvantage is that they are very noisy and unsightly (not pretty), so many people do not want them near their homes or in the countryside, ruining their view.

Biofuel

Biofuel is a renewable energy resource, as it can be replaced quickly, as biofuel comes from plants and animal waste (faeces/manure). These fuels are readily available because plants can be regrown and animals produce waste daily. The plant and animal waste is burned to heat water, creating steam that drives a turbine, which in turn powers a generator to produce electricity. There are buses in Bristol that run on the gas produced by human faeces! Biofuel is beneficial because it uses waste, but burning it produces carbon dioxide, a greenhouse gas, contributing to global warming.

Solar

Solar Panels use the Sun's thermal energy to heat water, which can be used in our homes for showers and taps. However, the most common type of solar panel is made of solar cells that use sunlight to knock electrons loose from atoms in the solar cell, creating free electrons. This flow of free electrons then creates an electric current. Solar power is a renewable energy resource, as it is sunny most days; however, it is more useful in countries that receive much more direct sunlight than the UK. It can be an unreliable energy resource in the UK as it is not always sunny.

Geothermal

Geothermal energy uses the heat in the Earth's interior to heat water. Water is pumped underground to be heated by magma in underground reservoirs. The heated water turns into steam, which spins a turbine, converting thermal energy into kinetic energy. This drives a generator to generate electricity. This is a renewable energy resource, as we use magma in the Earth (when magma rises to the Earth's surface through volcanoes, it is called lava). This is a reliable energy resource, but a disadvantage is that geothermal power stations are expensive to construct and can be built only in specific locations.

Hydroelectricity

Hydroelectricity uses water stored high up in reservoirs by dams, which is then released to flow down and spin a turbine at the bottom that drives a generator to produce electricity. This is a renewable energy resource, as we use moving water to generate electricity. A disadvantage is that the dams can cause flooding and destroy habitats.

Tides

On Earth, we have high and low tides due to the Moon's gravitational pull. The high and low tides are used to spin underwater turbines that drive a generator to generate electricity. This is a renewable energy resource, as we use moving water to generate electricity. Tidal is a reliable energy resource, as tides occur naturally every day.

Water Waves

Special mechanical devices are placed in the ocean to use the energy from waves to spin a turbine that drives a generator to produce electricity. Waves are predictable and consistent, making them a renewable and reliable energy resource. However, the technology is expensive and can impact marine life.