Types of renewable energy

Wind

It’s got nothing to do with beans. People have been harnessing the wind for centuries and today’s hi-tech wind turbines make a big contribution to Britain’s energy. We think they’re beautiful, others aren’t so sure, which is why offshore wind farms are a good compromise. They promise to deliver even more energy and several large-scale offshore wind farms are currently under construction.

Solar

The sun’s no good for wrinkles but it is good for heating (solar thermal energy) and creating electricity (photovoltaic energy). Unfortunately our damp little island isn’t the sunniest place in the world, so it hasn’t really caught on as a major energy source.

Hydropower

Water is pretty heavy stuff, just ask anyone who’s had a water bomb on their head. Hydropower uses this principal on a much larger scale by harnessing the power of rapidly moving water. It’s not as much fun as a water bomb, but it does create a lot of energy by turning turbines, either from waterfalls or fast-moving rivers.

Tidal

The moon has been pulling our seas in and out every day for millions of years. However, harnessing the power of the tide must be weighed against the impact on our rivers and coastline. Tidal power is still in its infancy, but one of the most well-known tidal projects is the Severn Estuary. If successful it could generate up to 5% of the UK’s total electricity requirements.

Geothermal

We’re standing on a potential renewable energy goldmine. Geothermal energy involves extracting heat energy from deep within the earth itself. It’s a potentially inexhaustible, reliable and clean source of energy and is already common in countries like Iceland. New technology is enabling geothermal energy to become economical across a much wider area than was possible in the past, adding to its future as a universal energy source.

Biomass

Biomass energy is the burning of materials such as wood and manure, including crops grown specifically for the purpose. Even though this gives off CO₂, the carbon is captured and used in the growing of new crops. Biomass energy also refers to gases like methane, which are given off by human waste decomposing in landfill sites. This gas can also be captured and turned into electricity, just make sure you hold your nose.

Landfill gas electricity generation

Most of our rubbish goes into landfill. It’s not ideal, but there is an upside. Drill a well into a land fill site and we can extract the methane it gives off. This can be used to fire generators and create electricity. There’s another benefit too. Trapping and using methane like this means it can’t escape into the atmosphere where it’s 23 times more harmful than CO₂.

Anaerobic Digestion

It sounds like something out of a gory horror movie, but it’s actually closer to what happens in a cow’s stomach! It works by placing organic matter into an oxygen-free atmosphere called an AD unit. The bacteria in the unit decomposes the material which releases methane. This can be extracted and used as a bio-gas or alternatively burnt to fire electricity generators. It’s great for farms as it relies on a constant supply of organic matter.