I recently wrote a persuasive writing article for one of my modules on "25% Renewable Energy is Achievable" (I'm arguing that it is achievable) and so here it is, in all of its 1,500 word glory! Enjoy.
Energy is, and has always been, an important issue. From early man in search of firewood to the latest research on nuclear fusion, we have always needed and used energy. The situation has changed in the last 20 years with the new links of fossil fuels to global warming. It has been repeatedly shown that it is not sustainable for us to keep burning fossil fuels, and so we must look for other sources of energy to satisfy our appetite for energy. Ideally we should aim for a goal of 100% renewables, which would have no impact on the world around us. However, this is a highly optimistic view, and a longer-term aim. That does not mean that we should not aim this high – a long-term goal is always a good idea – but we should be more reasonable in the short term. I believe that 25% renewable energy is an achievable goal in the next 100 years.
Before we begin discussing this issue in detail, it would be useful to clarify the question being addressed. I interpret our overall aim as 25% of the UK’s electricity production to be from renewable energy. The definition of renewable is also important; I will use the following definition: “Renewable energy is natural energy which does not have a limited supply. Renewable energy can be used again and again, and will never run out.” [1] Therefore, renewable energy includes (but is not limited to) wind, tidal, solar and hydroelectric. Some notable omissions are fusion, which has the potential to have fuel to last for a million years [2], but would still run out eventually, and biofuels, which can only be used once.
Let’s also give the state of affairs now, so we know how much work there is to be done to achieve 25% renewable electricity production. In 2009, the total UK electricity production was just over 379 TWh [3], of which 6.7% was generated by renewable energy. A quarter of this, the 25% we are aiming for, is 95 TWh. As is obvious by these statistics, there is much work to be done. I will take each of the major renewable energy in turn, considering how much potential electricity that particular source offers.
First, we will look at wind power. The sources of wind are “the uneven heating of the atmosphere by the sun, the irregularities of the earth's surface, and rotation of the earth” [4] and this wind can be used to generate electricity by breaking the flow with a turbine. This type of electricity production is widely hailed as being the flagship of renewable energy in the UK, and rightly so: the Sustainable Development Commission pronounced “The UK has some of the best wind resources in Europe, if not the world, in both onshore and offshore locations” [5.1]. Both onshore and offshore wind resources will be considered here. A practical limit of 50,000 GWh per year is given for the onshore wind in the report by the Sustainable Development Commission [5.2]. This practical limit includes the maximum theoretical energy production, with “consideration of planning, environmental and
social issues” [5.2]. For offshore wind, an estimate of 100,000 GWh per year is suggested in the same report. This adds up to a total of 150 TWh per year of wind resources in the UK. The technology for this type of electricity generation is already in place and well developed; the Government said in 2007 that wind energy alone could power up to 20% of the UK’s electricity production [6]. The potential for this energy resource is evidently huge: without any other energy source, it would still be easily enough to produce our 25% target of 95 TWh/year. However, the reliability is an issue: wind patterns are extremely hard to predict even a few days in advance, and, as such, storage and supplementary energy infrastructure would be needed to account for the variability in the wind power supply.
Tidal energy is another renewable source. The UK is an island, and as such has a large availability of this resource, in the powerful Atlantic Ocean tides. The estimated extractable energy from the tides around the UK is 94TWh/year [7]. This value could well be underestimated too, with papers in the peer-review phase suggesting that the above estimate could be 10 or even 20 times larger [7]. I am hopeful that this huge potential source of renewable energy will soon start to be explored with emerging technologies, as it would provide almost our entire renewable target. Another advantage of this type of energy source is that although the power output does vary with the tides, this variation is extremely predictable and “can be accurately predicted over the lifetime of the installation.” [7].
Solar power will now be considered. There are two main types of solar energy production: solar heating, where the sun heats up water to be used for domestic or industrial purposes, or in producing electricity in the familiar photovoltaic cell. The solar heating case is a worthwhile investment, but as we are solely considering electricity production, I will discount it. Although Britain has substantial wind and tidal energy resources, we are not the sunniest country, and so solar energy on a large scale is not as economically viable when compared to other renewables. There is, therefore, little data on the solar energy in the UK and a reliable estimate could not be found.
Hydroelectricity is a renewable source of energy which has been used for centuries in water wheels and similar machines. Modern installations generate electricity by damming a river, stopping the water naturally flowing and forcing it through a pipe containing turbine. When the water goes through the pipe, it turns the turbine, turning a generator and producing electricity. The power produced by the hydroelectric plant can be predicted accurately. This system can also be used as a method of storing energy, by pumping water upstream to the reservoir. This can help to even out the flow of electricity across the grid caused by changes in demand or production: for example, if the wind is not blowing through a wind turbine. The power generated by a hydroelectric site is very site-specific [8], but a general estimate could be made for the total energy that could be produced. There is an estimated 146,280-248,400 kW of hydroelectric power potential in the UK [9], which is roughly equivalent to 500 GWh per year in hydroelectric power in the UK.
Adding this all together, we find that there is a total possible output of 245 TWh per year. This is substantially more than the 25% electricity supply from the current consumption (95 TWh), and would also easily be enough to accommodate increases in electricity use. I argue, therefore, that this is a highly achievable goal. The UK has huge renewable energy resources that, if properly developed, will power our lives for generations to come.
Those who believe renewable energy is not the answer often say that it will be impossible to get near this potential power output, due to the lack of economic motivation. However, there has been a change in political and individual outlook over the last 20 years: global warming is now widely accepted, and significant investment into renewable energy, could prevent enormous change in the world as we know it. This is surely motivation enough for investment, and the prices of renewably-generated power are starting to reach those of traditional fossil-fuel powered power. Critics also argue that we lack the technology to generate energy on this scale. I respond to that by examining occasions throughout history when we have put our minds to developing a technology beyond its initially assumed limits. First of all, the car; 100 years ago, the internal combustion engine was more of a plaything than a viable mode of transport; now, there are over 31 million cars in the UK [10]. This is due to an incredible amount of research and investment into the study and development of the car. If similar research was done on renewable energy, then we would be easily at 25% renewables within 100 years. There is nothing that we as a group, country or world cannot achieve.
I believe that it is an entirely achievable target to have 25% renewable energy sources behind our UK electricity production. This target would mainly be met by using our wind and tidal resources, but there are others, such as hydro-electric and solar, which could supplement the energy supply. Although these are theoretical estimates, I believe that it is highly possible to attain these values and generate clean, renewable energy for generations to come. With the help of the government and private companies, investment into developing better technology to make use of these plentiful renewable energy sources will pay off.
BIBLIOGRAPHY
References:
[1]: Clean energy ideas, definition of renewable energy 2009. Available from: http://www.clean-energy-ideas.com/energy_definitions/definition_of_renewable_energy.html [13 November 2010]
[2]: MacKay, D JC, Sustainable energy- without the hot air 2010. Available from: http://www.inference.phy.cam.ac.uk/withouthotair/c24/page_173.shtml [13 November 2010]
[3]: Department of Energy and Climate Change, Digest of United Kingdom Energy Statistics 2010 2010. Available from: http://www.decc.gov.uk/assets/decc/Statistics/publications/dukes/348-dukes-2010-printed.pdf (page 115) [13 November 2010]
[4]: Wind Energy Development Programme EIS, Wind Energy Basics, n.d http://windeis.anl.gov/guide/basics/index.cfm [13 November 2010]
[5]: Sustainable Development Commission, Wind power in the UK 2005. Available from: http://www.sd-commission.org.uk/publications/downloads/Wind_Energy-NovRev2005.pdf pg 15 [13 November 2010]
[5.1]: page 13
[5.2]: page 14
[6]: Louise Radnofsky, Wind energy to power UK by 2020, government says 2007. Available from: http://www.guardian.co.uk/environment/2007/dec/10/politics [13 November 2010]
[7]: Sustainable Development Commission, Tidal power in the UK 2007. Available from: http://www.sd-commission.org.uk/publications/downloads/Tidal_Power_in_the_UK_Oct07.pdf [13 November 2010] (page 23)
[8]: The Renewable Energy Centre, n.d., Hydroelectric Power. Available from: http://www.therenewableenergycentre.co.uk/hydroelectric-power/ [13 November 2010]
[9]: Department of Energy and Climate Change, England and Wales Hydropower Resource Assessment 2010. Available from: http://www.british-hydro.org/UK%20Hydro%20Resource/England%20and%20Wales%20Resource%20Study%20Oct%202010.pdf [13 November 2010] (page 18)
[10]: David Millward, Number of cars declines for the first time since Second World War 2010. Available from: http://www.telegraph.co.uk/motoring/news/7563297/Number-of-cars-declines-for-the-first-time-since-Second-World-War.html [14 November 2010]
Other sources of information:
http://www.environment-agency.gov.uk/shell/hydropowerswf.html
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