Renewable energy is simple enough: the electricity we need every day, created by sources which are naturally replenished. There is no strict definition of what renewable energy is and debate rages about which sources can produce renewable energy.
Indisputable types of renewable energy include: wind, hydro and solar. All these things occur naturally without man-made intervention (although in the case of hydropower, we might tinker with river systems to get the most out of them). These renewable energy technologies have been used for many years; hydropower has generated renewable electricity since the 1800s (after all, it’s not a great leap from traditional waterwheels to electric dynamos).
Other, less common, forms of renewable energy include biomass, biofuel and anaerobic digestion. Some suggest that these forms of renewable energy supply are not strictly renewable: we require animal waste for anaerobic digestion and artificial forest plantations for biomass. Nonetheless, to meet our high electricity demands, these sources of renewable energy are preferable to non-renewable energy, also known as ‘brown’ energy.
Below you will find brief descriptions of the various types of renewable energy technology around with links to further information.
Hydropower renewable energy is electricity generated by the passage of water through a turbine, which causes a dynamo to spin. Hydropower is one of the greatest renewable energy sources on Earth, currently accounting for 20% of the world’s electricity and 90% of all renewable output.
Hydropower plants are comparatively cheap to build, easy to maintain and are one of the most efficient electricity generating sources. Some countries are already highly reliant on hydropower; Norway, for example, sources 99% of its electricity from hydropower plants.
Wind renewable energy uses large blades to spin a dynamo inside the turbine. Many countries have access to wind, although supply is intermittent. Onshore wind turbines are fairly cheap and easy to run. However, they have less generation capacity than offshore wind turbines, which have a stronger and more predictable supply of wind but are more expensive to install and can be difficult to maintain.
The UK has great wind renewable energy potential, particularly in the off-shore market, and around 40% of Europe’s wind resource blows over the UK.
Solar renewable energy, also known as photovoltaic renewable energy, harnesses the power of the sun to produce electricity. Solar cells convert the sun’s energy into electricity through semiconductors. Although a complicated technology, solar PV can be deployed in compact panels, turning roofs into the perfect energy-generating platform.
In the right environment, photovoltaic energy is predictable and, for this reason, solar renewable energy is popular in southern Europe.
Anaerobic digestion renewable energy produces electricity through the decomposition of organic matter in silos, with the addition of microorganisms and in the absence of oxygen. It is similar to composting, although this takes place with oxygen.
Manure, vegetation and wastewater are common additions to AD silos. The process by which these products are broken down creates methane, which is then burned to produce electricity. The surplus of these raw materials and the by-product of sanitised compost ensure that anaerobic digestion renewable energy plants can often be found on farms.
Biomass renewable energy can be generated in a number of ways but it is derived ultimately from plant matter. This can include dead wood from forests, although most biomass is grown specifically for electricity generation. Popular biomass crops include willow, hemp and poplar. Logs can be used but it is common, and more energy efficient, to use dense wooden pellets.
Biofuel renewable energy
Biofuel renewable energy is similar to biomass in that it revolves around organic matter. Crops, such as sugar beet, soya or oilseed rape, are grown and burned (also anaerobically) to produce a liquid, gas or solid fuel source. This, in turn, can be burned to produce electricity or mixed with other fuels to power transport.
Why should we increase our renewable energy usage?
The environmental debate
Familiarity with global warming
is a fact of modern life. Briefly put, the burning of fossil fuels, such as coal, oil and gas, to produce heat, electricity and in transport produces greenhouse gases, including, but not limited to, carbon-dioxide and methane. Gasses like these act as a blanket in the atmosphere, preventing heat from the sun from escaping back into space.
Furthermore, whilst advances in technology have ensured that atmospheric pollutants
are not the problem they once were, particles released in the burning of fossil fuels, including sulphur dioxide and heavy metals, cause acid rain, respiratory problems and water pollution.
The fuel security debate
Much of the UK’s energy is derived from imports of oil and coal from around the world. Even though we derive nearly half of our electricity from gas-fired power stations, the UK’s known gas reserves are running low and we already import much from Norwegian North Sea gasfields.
The price of our electricity, heat and transport is inextricably linked to oil and coal prices
, which are affected by macro-economic factors completely outside of our control but which still impact on our budgets.
Furthermore, as political tensions continue to heighten in eastern Europe and the Middle East, it would be politic for the UK to secure as much of its own energy generation as possible, with renewable energy an obvious and largely untapped resource.
Energy saving initiatives are certainly laudable, but there will always be high electricity demand if we are to maintain anything like our current standards of living. Continued investment in renewable energy is of fundamental importance if British homes and businesses are to do their part in reducing carbon emissions, protecting their long-term financial health and protecting the country’s energy security.