What is renewable energy?
A source of energy is considered renewable when it can be used again and again without running out. Currently we use very little renewable energy to power our homes and transport. Instead around 87% of our energy comes from burning fossil fuels and only 8% from renewable sources combined!
Types of renewable energy
Solar, hydroelectricity, wind, marine (wave and tidal), geothermal, bioenergy and hydrogen, are all types of renewable energy we can use to get power. These pages will give you information including costs, environmental and human impact, and whether that energy would be useful for the UK.
Nulcear power also gives us some of our energy, but there is a debate over whether this is really a type of renewable energy or not and therefore is not included in this Renewable Energy section. You can find out more about nuclear power on our Nuclear Power page in the Energy Crisis section.
Which is the best kind of renewable energy?
Well, it’s not quite as simple as that. It is extremely unlikely that one particular type of renewable energy will ‘solve the world’s energy problems’. One of the difficulties with renewable energies is that they tend to rely on natural resources, and these are not always very consistent. Does the wind always blow when we need it? Does the sun always shine? No. What we need to see in the future is all the renewable energies working together and supporting each other – teamwork!
Some resources have a greater potential than others in terms of how much energy they could contribute. The picture below shows the upper limits of some of the renewable energy sources. These numbers are absolute maximums and are actually very unrealistic. We could only harness 3 TW (TW = Terawatt) of hydroelectric power if we built dams across every single river; could only achieve 12 TW of geothermal power if we tapped into every possible land source across the world; could only extract 4 TW of wind power if we were to cover the earth in turbines. Even the potential 100 TW from bioenergy isn’t as promising as it looks, unless we wanted to stop growing food crops and instead saturate the land with energy crops!
This picture shows the maximum possible power we could capture from these renewable energy resources. Estimates from DOE Report, “Solar Energy Utilization”, 2006
The sun is so powerful that if we were able to harness all its energy, it could provide almost 10,000 times as much energy as the whole world needs! Explore our Solar Technology pages to find out how scientists are trying to capture as much energy as they can. It is unrealistic to imagine being able to capture all of that energy exactly when we need it, so solar energy must be complemented by other renewable energy sources.
In our pages you’ll find information about all kinds of renewable energies, and loads of information on solar energy. For more even more information, check the external links.