November 8, 2017
There are many different types of renewable energy. They fall into the categories of Wind power, Hydropower, Solar, Geothermal and Bioenergy.
Wind power is created through wind turbines. These are often placed in locations where wind is constant and strong, such as offshore or at high altitude. Wind power met 4% of global electricity demand in 2015, and contributed 11% of UK energy in the same year. The following year, the UK generated more electricity using wind power than using coal. Wind power tends to be consistent in the long term, but in the short term (day to day, hour to hour) it can be unreliable. The London Array is the world’s largest offshore wind farm – it is off the coast of Kent in the Thames Estuary.
Hydropower is generated using water. In 2015, it generated 16.6% of the world’s energy. It falls into four main types – tidal, run of the river, dams and pumped storage. Tidal power converts the energy of the tide from the ocean’s surface waves and turns it into power. Run of the river captures energy in small rivers through the movement of the water as it goes downstream. Dams store up water in larger rivers and use it to drive water turbines, which power a generator. Pumped storage supplies electricity when demanded by moving water from a higher elevated reservoir to a lower one.
Solar power harnesses heat and light energy from the sun’s rays by using a photovoltaic system to convert the solar energy into usable power. It is often used to heat water. There is a high availability of solar energy, and it could potentially fill the entire world’s demand for energy. However, it is difficult to effectively harness solar power.
Geothermal energy uses heat from the earth. This heat originates in the Earth’s core and travels up to the surface. It is most commonly used in the US, and is used for heating. Historically, geothermal energy has been limited to tectonic plate boundaries, but recent advances mean that there are more viable sources of geothermal energy. Geothermal wells release greenhouse gases meaning that geothermal energy is not clean energy like solar, hydro and wind. But, geothermal energy has lower emissions than fossil fuels.
Bioenergy is electricity made from biological products like sugarcane and palm oil. It is derived from anything biological with stored chemical energy, which originated from the sun. Bioenergy has an impact on climate as it can cause damage to ecosystems through deforestation and use of resources.