Question - Wind Power as renewable energy, will it work?
The Engineering Design and Sustainable Systems module has been quite interesting and this assignment takes the fascination further. The assignment requires us to write an essay on sustainability, renewable technologies or environmental design. I have chosen to write on wind power because it is a source of renewable energy and it is sustainable. Wind energy and technology is only one type amongst the many sources of renewable energy, all of which have their advantages and challenges. This paper will research and discuss the Renewables but its focus will be on wind energy. I will discuss how it works and the advantages and the disadvantages of the source. I will also endeavour to draw a meaningful conclusion from my research.
Background - Energy consumption in the world
No other subject can be more topical than the issue of energy production and usage, greenhouse emission and climate change. It is exercising individuals as well as nations, be they small or big, developing, emerging or developed. As a matter of fact, environmental issues and the scramble for a more sustainable and renewable energy are ranked as high as terrorism and war amongst the issues that test international relations.
The 20th century saw a massive increase in the use of fossil fuels, especially coal which drove the industrial revolution of the 18th and 19th century. With the discovery of oil, coal took the back seat for a short while before experiencing a further resurgence along with nuclear power. It is reported that fossil fuel still accounts for an estimated 86% of energy supply in 2004 and in 2005 nuclear power accounted for an approximately 6% of the world's energy supply. It follows that the dirtiest source of energy, coal, is still the most widely used worldwide.
Apart from the cleanliness issue, the other challenge with fossil fuels, especially oil is price fluctuation in stock market which a knock-on effect on nations' economy. Nations are always wary of any change in the price of oil and the impact on their economy. In spite of what most western governments contend, it is extremely difficult to think that the war being fought in Iraq has nothing to do with oil. America needs oil Europe needs oil, the whole world needs oil. America's very high energy consumption rate is the reason it is reluctant to commit fully to the Kyoto Protocol and other initiatives that seek to cut greenhouse gas. It is an industrial nation but also a nation of gas-guzzling vehicles. Try as the British government may, it has found it very difficult to convince the electorate that there was no ulterior motive for "standing shoulder to shoulder" with America on the Iraq war.
The emerging economies of China and India have started scrambling for oil and other sources of energy. China is now one of the highest energy consuming nations in the world and is expected to overtake the US very soon. Yet oil and natural gas are only produced in a handful of Organisation of the Petroleum Exporting Countries (OPEC). Any instability or local issues in any of these countries is enough to send the price of these natural products either sky high or crashing. Civil unrest, political instability, diplomatic scuffles have all had impacts in the price of oil.
As recently as 2008 when Russia fell out with its neighbour Belarus, it shut down the gas pipeline to Europe. This made the British Prime Minister declare that 'No nation can be allowed to exert an energy stranglehold over Europe,'. He promises urgent action to prevent Britain 'sleepwalking into an energy dependence on less stable or reliable partners', including seeking out alternative suppliers of gas and oil, as well as pushing ahead with plans for new nuclear plants and alternative fuels. Gordon Brown added that there was an urgent need to move to stop Britain's reliance on Russia's gas and oil. Basically, Russia knows the kind of power that it has over other European countries and does not hesitate to use it as leverage whenever it sees fit. Russia is currently feeling vulnerable and wants to reinstate itself as a superpower. Oil can be a useful weapon. This type of energy cum diplomatic crisis happens in one form or another every year.
So oil and gas reserves are held by a handful of countries and are therefore volatile, and coal is not environmentally friendly because of its carbon content. Generally, fossil fuels are finite sources of energy, fast depleting and are impacting the environment. Some people have gone as far as to claim that climate change is a greater threat to the world than terrorism. This has served to strengthen the world economies' resolve to search for more sustainable and renewable energy for industrial and domestic use. In addition, no country really wants to be at the mercy of another country to keep their economy moving.
Nothing illustrates the polemic nature of the issue of climate change than the recent event in the climate change summit that took place in Copenhagen in 2009 where developed (rich) and developing (poor) countries engage in a blame game faced with the important decision of reducing emission. The rich countries blame the poor for dwelling too much on the process while the poor countries feel that the rich ones 'refused to lead and instead sought to bribe and bully developing nations to sign up to the equivalent of a death warrant'.
There is no doubt that the world needs an alternative source(s) of energy that would not only be cost effective and clean but also available all the time i.e there is no risk of depleting. Whatever alternative it is, it should be at such quantity that it would be able to heat/cool homes and support the industrial development that every nation needs to improve, maintain (or increase as the case may be), its economical development.
So what is sustainable/ renewable energy? Wikipedia defines sustainable energy as 'the provision of energy such that it meets the needs of the present without compromising the ability of future generations to meet their needs'
Renewable energy is defined as 'energy which comes from natural resources such as hydropower, sunlight, wind, rain, tides and geothermal heat (heat from earth) which are renewable or naturally replenished.' All these sources of energy have been used in varying degrees and intensity across the world and preference for a particular type depends on how readily available it is in the part of the world concerned. What the search for new sources of energy proves is that there is a consensus that the world needs new sources of energy to cope with our energy gluttony.
Most countries have been using a combination of sources to cater for their energy needs. What needs to happen is an increase of investment in Renewables. A large number of countries have renewable energy policies and targets in place. This however, has increased or decreased in light of the recent global economic recession. The UK as a nation aims to produce at least 15% of its energy from renewable sources by 2020 which equates to approximately one-third of its electricity requirements. China is proposing a big increase in its use of wind and solar power over the next few years and the US recently made a proposal to create a renewable power target of 15% by 2020 too. 'The UN believes $750bn needs to be spent worldwide between 2009 and 2011'. At the last International Energy Forum (IEF) in Cancun, the meeting closed by a statement from producers and consumers affirming that all energy sources - including nuclear and wind power - must be used to meet the projected rise in energy demand in the coming decades.
The graph below shows the worldwide energy sources in TerraWatts (TW) as at 2004 It can be seen that there is still a huge dependence on oil and coal while the Renewables are still low.
The following graph shows Renewable energy sources in GigaWatts (GW) as at end of 2008. The graph shows that hydropower still dominates among the Renewables. However, there is a movement away from some types because of the need to dislocate people where reservoirs are planned and the risk of flooding.
As stated above, the focus of this paper is wind energy which as the name implies uses wind to generate power most of which comes from turbines. Winds are created by uneven heating of the atmosphere by the sun, irregularities of the Earth's surface, and the rotation of the Earth. As a result, winds are strongly influenced and modified by local terrain, bodies of water, weather patterns, vegetative cover, and other factors. The wind flow, or motion of energy when harvested by wind turbines, can be used to generate electricity.
Wind is a clean source of renewable energy because it produces no air or water pollution. It is free and as a consequence involves very little operational cost. The cost involved is mostly related to the installation and maintenance of the turbine itself. Wind power is widely used in Europe, Asia and America and the current estimate puts its growth rate at 30%. As a matter of fact in the UK, it is now compulsory for energy suppliers to ensure that a certain percentage of their energy comes from a renewable source and wind energy is proving to be popular choice.
How it works - The turbines can be extremely tall. Some are as tall as a 20-storey building and the blades can be up to 60m long. When the wind blows, it spins the blades that turns a shaft which is connected to a generator that produces electricity.. The average output for a modern wind turbine ranges from 600kW to 5MW although the most common for commercial use have an output ranging from 1.5 - 3MW.
How a wind turbine works
Onshore or offshore
Wind turbines can be situated onshore or offshore and the smaller ones can be put in the back garden for domestic use. The term wind farm is used when hundreds of the turbines are installed in windy area to get the maximum exposure. However, one of the drawbacks of the system is that if there is no wind, no power is generated and as such, a form of back up would be required.
The International Energy Agency (IEA) targets 12% of global electricity to be generated by wind power by 2050. The agency considers that 2000GW of capacity will annually avoid the emission of 2.8 gigatonnes of CO2 equivalent. IEA reports that wind farm can be quite competitive where the resource is available and that the relative high cost involved in setting it up would be reduced considerably with advancement in technology. In the meantime, help from government in form of subsidies or research development might be necessary.
Research in support of the Kyoto Protocol has shown that 'consumption of renewable energy, which results in no net carbon emissions, is projected to be significantly higher with carbon reduction targets. Across the carbon reduction cases, renewable energy consumption increases by between 2 and 16 percent in 2010 and by between 9 and 70 percent in 2020. Most of this increase occurs in electricity generation, primarily with additions to wind energy systems and an increase in the use of biomass (wood, switch grass, and refuse). In the carbon reduction cases, the share of renewable generation is as much as 14 percent in 2010, compared with 10 percent in the reference case, increasing to as high as 22 percent in 2020, compared with 9 percent inthe reference case.'
Wind Energy use
Wind energy can be used for industrial and domestic purposes. There are small sized turbines that can be installed in back gardens for domestic use and the larger types are usually connected to the national grid. For this reason, they need to be sited near the facility.
- Wind is free.
- New technologies make wind extraction more efficient
- The turbines exist in varying sizes to support different uses - industrial or domestic
- The intensity of the wind farm can be according to the use
- Wind energy is environmentally friendly - since there is no burning of fossil fuels no carbon is released in the process of generating electricity.
- Wind turbines do not take as much space as the average power station. Although they need to be spaced out and occupy a few square metres at the base, other activities like agriculture can still go on between each turbine.
- It can be a solution for countries where power generation or supply is very difficult.
- Wind energy can be combined with other renewable sources to provide back-up
- There is little operational cost once set up
- Difficult to obtain planning consent (on-shore and off-shore) - lengthy processing time, objections from airports, 40% approval rate
- Visual intrusion - some people feel the turbines are unsightly but technology could improve this
- Noise impact
- Shortage of spare parts for generators for turbines
- Some operate at less than 10% capacity compared to 80% for nuclear plant for example
- Issue of how much back up is required is still to be resolved
- Wind farms require large expanse of land
As the current trend is to move away from fossil fuel, the options left for most countries are coal, nuclear power and the renewable energy. In view of the need to protect the environment, coal is not ideal because of its high carbon content and the potential to harm the environment. However, this option cannot be ruled out completely as a number of countries e.g, the UK is considering the option of investing in clean coal which involves carbon sequestration.
Perhaps the most controversial of all energy sources is nuclear power. Concern has been expressed for safety during operation and disposal when the plant has reached the end of its life cycle. Nevertheless, some countries carry on building new plants. For example the, UK government has announced its support for new plants to be built and a number of suppliers like EDF, E.ON and Centrica have expressed an interest in building more plants.
Renewables seem to be the source enjoying popularity albeit to varying degrees. There is no doubt that wind energy is both sustainable and renewable. It is sustainable because as long as the earth exists there will always be air and no generation can use up the next generation's allocation. It is renewable because it comes from natural source and is naturally replenished. There is no carbon by-product, therefore it is very clean. Wind energy qualifies on the two counts.
Wind power definitely has a future and there is no doubt that with technological advance, it would become very popular. The UK Government has set a target of producing 20% of electricity in the UK through renewable energy by 2020 and a fair chunk of this is projected to come from wind farm. Because wind energy does not produce any carbon emission, I believe that it is definitely an option worth pursuing.
Nevertheless the following challenges need to be overcome:
- Acceptance by the public
- Tech advancement to make it cheaper
- Tech advancement to make it less noisy
- Tech advancement to increase capacity
- It cannot be used exclusively - it needs back-up
However, because of its strategic location requirement, a combination of sources would be ideal. This is because of the challenge posed by the gargantuan size of the turbine which provokes strong feelings from people concerned about aesthetics.