An Introduction to Renewable Energy

It is clear – the days of mass reliance on fossil fuels is coming to an end. Gas, oil, coal; all of these are finite resources, and also, of course, come with a heavy environmental toll. Most people concur that a drastic global shift to renewable energy and sustainable technology is absolutely necessary, though there are areas of disagreement over the best technologies to use and how to implement them.

Renewable energy sources are are not used up, but keep going, or replenish themselves, within a timescale useful to human beings. The areas of use for renewable energy sources include electrical generation, both on and off-grid, heating for homes and hot water systems, and fuels for cars and other vehicles.

Wind power is one of the most visible forms of renewable energy used today: most people are familiar with the wind turbines which, in some countries, are becoming a common sight in the countryside and off-shore. Wind-powered electricity generation is cheap both monetarily and in terms of impact on the environment. In spite of concerns that have been raised over the manufacturing process for the turbines, wind power has one of the lowest carbon footprints of any of the renewable power sources, and is easily scaleable for individual use, and small communities.

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Another advantage to wind power is that it is also cheap in terms of land usage. Though they do cover a lot of land, that land is not rendered useless and can still be used to grow crops. The efficacy of wild power is variable though. Of course the energy generated will depend on the strength of the wind, which fluctuates wildly. Sometimes huge amounts of power can be generated but at other times the turbines may not be generating at all. Wind turbines must be sighted correctly, and locating them is one of the main bones of contention for those who object to the widespread use of this form of power generation. Some people object to the look or sound of the turbines.

More pertinent concerns include worries over the destruction of natural habitats. The construction of a wind farm, for example, on a peat bog, would be counter productive in terms of trying to achieve carbon-neutrality, since the peat bog itself is such an effective carbon sink. Studies have shown that the best location for large wind farms is off-shore, both in terms of reducing its impact on human and animal life, and also as regards the electricity production.
Solar power is also widely used, both for electricity generation, and hot-water systems. The power of the sun is harnessed through both passive and active means. Passive solar technologies are all about maximising the gain in heat and light (usually in an architectural context) by window design and positioning, orientation of the building, and the use of materials with thermal mass, which enables the building to store heat for later, and slowly release it. Active solar technologies include the use of photovoltaic panels, or concentrated solar power plants to convert sunlight into electricity, and solar hot water heating systems. Solar power is thought by many to be a very important and vital part of the solution to the global energy crisis, both in large-scale and small-scale ventures.

Harnessing the power of water to generate power is another form of renewable energy production, and, arguably, one that is still not used to its full potential. Large hydroelectric dams can and do create huge amounts of electricity, while other systems exploit a drop in altitude to convert kinetic energy to electricity. In developing nations, small-scale micro-hydro provides power generation for isolated or remote water-rich areas – these systems are particularly useful for picking up the slack at the time of year when solar power systems are at their least effective.

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Biomass is the name given to organic materials that can be used to generate power, either directly, by burning it, or indirectly, through the use of plants as fuel. The most common biomass material is wood, though many other materials are used. Burning wood is sustainable for space heating on a small scale but, arguably, the use of biological material for large-scale energy production is not the most efficient use of our planet’s resources.

Biomass must be grown, somehow, and often, land use is heavy. It could be argued at times that the land could better be used to grow food, or other useful crops. That said, the use of by-products of other systems can and should be used as one piece of the renewables jigsaw, especially as regards the production of biofuels for automotive use.

 
Geothermal is all about harnessing the heat of the Earth. Romans used it to heat their houses, and for centuries people have bathed in hot springs, but now it is also possible to generate electricity in this way. One of the cheapest and most environmentally friendly of all renewable technologies, geothermal power generation is on the increase due to advances in the technology which means it is now also usable further from the edges of tectonic plates. This is definitely a technology that will and should be utilised more widely in the future.

 
The range of renewables and the constant advance of technologies mean that we should not feel despondent about the future, or the fact that peak oil is firmly behind us. We should instead do our best to work together towards a sustainable future for our beautiful planet.