Executive Summary
In order to produce an additional two Giga-Watts of renewable energy in the United Kingdom our team has determined that a mix of these renewables would be ideal.
This analysis has been conducted by accounting for economic factors, the demand for electricity within the UK, social factors and the long-term environmental benefit of these renewable energy sources.
Introduction
Energy production is considered one of the most significant challenges in the world. Demand for electricity is increasing due to the rapidly increasing world population and growth of industries. The UK and other developed countries have begun to start looking for renewable sources of energy to increase their energy security and to reduce the greenhouse gases and carbon emissions. The climate science community has agreed that the greenhouse gases that release to the environment must be reduced at least (80-90) percent by 2050 to avoid climate change challenges. The legislation has been put in place by UK government to reach this reduction the emissions by 2050 to 80% compared to 1990 (Pfenninger and Keirstead 2015) .Low carbon energy is represented as many different forms such as nuclear power, power plant that employ carbon capture and storage (CCS) and large scale renewable energy such as wind or hydroelectric energy (Ekins et al 2013).
There are several different forms of geothermal power, which can be used to provide electricity to homes with little to no environmental impact. The world leader is Iceland, which provides 25% of its electricity via geothermal energy schemes. However, not every country is blessed with the abundance of geothermal energy that Iceland has due to it geological position. Globally 11’000 MW of geothermal energy is produced with three countries taking the lion’s share of this. These countries are: The USA, the Philippines & Indonesia (bgs.com). Geothermal Energy can be found where there is an abundance of volcanic activity, which heats up the earth. The use of geothermal springs dates back to the 3rd century b.c, where the Chinese built a spa at a hot spring on the Lisan Mountain. Throughout history hot springs have been used to great spas or saunas for human pleasure.
How Wind Power Is Generated
The terms “wind energy” or “wind power” describe the process by which the wind is used to generate mechanical power or electricity. Wind turbines convert the kinetic energy in the wind into mechanical power. This mechanical power can be used for specific tasks (such as grinding grain or pumping water) or a generator can convert this mechanical power into electricity to power homes, businesses, schools, and the like. Wind turbines, like aircraft propeller blades, turn in the moving air and power an electric generator that supplies an electric current. Simply stated, a wind turbine is the opposite of a fan. Instead of using electricity to make wind, like a fan, wind turbines use wind to make electricity. The wind turns the blades, which spin a shaft, which connects to a generator and makes electricity.
Wind energy or wind power refers to the process of creating electricity using the wind, or air flows that occur naturally in the earth’s atmosphere. Modern wind turbines are used to capture kinetic energy from the wind and generate electricity. There are three main types of wind energy namely:
- Utility-scale wind: Wind turbines that range in size from 100 kilowatts to several megawatts, where the electricity is delivered to the power grid and distributed to the end user by electric utilities or power system operators.
- Distributed or “small” wind: Single small wind turbines below 100 kilowatts that are used to directly power a home, farm or small business and are not connected to the grid.
- Offshore wind: Wind turbines that are erected in large bodies of water, usually on the continental shelf. Offshore wind turbines are larger than land-based turbines and can generate more power.
DISCUSSION
Nuclear energy
Nowadays, nuclear energy contributes about one third of the world’s low carbon power generation. Low carbon emission countries are mainly dependent on low carbon technologies to produce energy such as nuclear power and hydroelectric. However, nuclear energy has been developed slowly because the high cost of nuclear power (Lovering et al. 2016). Many nuclear reactors were being constructed by United Kingdom, Canada and Germany in addition to United States and France. However, in 1990s, the west European countries and United States stopped constructed nuclear power plants (Lovering et al. 2016). Nuclear power contributed approximately 14% from global electricity and because of the social concern regard the safety of nuclear energy, the (Kuo 2014). United Kingdom has eight nuclear power plants that basically divided in two types of reactors the first one is advanced gas-cooled reactor (AGR) and the second is a pressurised water reactor (PWR) (British Energy – Our Nuclear Power Stations 2018). There is a lot of debate about nuclear energy because the safety and social concerns. However, this report will not explain that as nuclear has been classified by UK parliament as non-renewable energy source (Energy and Climate Change Committee 2018).
Geothermal energy
Within the UK there is a market for geothermal energy but it is not as cost effective as the more established methods such as wind power or nuclear power. There is the ability to generate energy from geothermal wells such as aquifers or granite rocks. Throughout the United Kingdom the ground heats up at a rate of 26°C per 1km (bgs.com) and the hot rocks that are deep down in the earths crust often have water present flowing through them. It is possible in theory to recover this water and use it as a source of energy. Also there are several large deposits of granite in the United Kingdom, which may also be a source of geothermal heat. This is because is granite often heated up by the nuclear decay of potassium, uranium and thorium present in the rocks. However it is difficult to utilize granite as a source of geothermal heat because the rocks are often impermeable due to the lack of fractures and this makes it difficult to recover the heat via traditional means (The Engineer 2010).
There is another market in the UK, which is solar geothermal energy, which relies on the sun to heat up the ground, from which energy can be extracted to heat or cool homes. The ground at a depth of fifteen meters stays at a constant temperature throughout the year and thus is cooler than the air in the summer and warmer in the winter. By utilizing this temperature difference heat pumps can be used to drastically decrease the utility bills of houses and commercial buildings.
The largest geothermal power scheme in the UK is the Southampton District heating Scheme, which provides energy for many of the buildings in the city center. To this day it produces 18% of that districts electricity, with non-renewable energy making up the rest (Smith 2001). This power generation scheme utilizes a well that draws water from an aquifer at a depth of 1800 meters and at 76°C .
(Kuo, 2014)
Wind-Generated Electricity
Wind energy is a free, renewable resource, so no matter how much is used today, there will still be the same supply in the future. Wind energy is also a source of clean, non-polluting, electricity. Unlike conventional power plants, wind plants emit no air pollutants or greenhouse gases. According to the U.S. Department of Energy, in 1990, California’s wind power plants offset the emission of more than 2.5 billion pounds of carbon dioxide, and 15 million pounds of other pollutants that would have otherwise been produced. It would take a forest of 90 million to 175 million trees to provide the same air quality.
Cost Issues
Even though the cost of wind power has decreased dramatically in the past 10 years, the technology requires a higher initial investment than fossil-fueled generators. Roughly 80% of the cost is the machinery, with the balance being site preparation and installation. If wind generating systems are compared with fossil-fueled systems on a “life-cycle” cost basis (counting fuel and operating expenses for the life of the generator), however, wind costs are much more competitive with other generating technologies because there is no fuel to purchase and minimal operating expenses.
Environmental Concerns
Although wind power plants have relatively little impact on the environment compared to fossil fuel power plants, there is some concern over the noise produced by the rotor blades, aesthetic (visual) impacts, and birds and bats having been killed (avian/bat mortality) by flying into the rotors. Most of these problems have been resolved or greatly reduced through technological development or by properly siting wind plants.
Supply and Transport Issues
The major challenge to using wind as a source of power is that it is intermittent and does not always blow when electricity is needed. Wind cannot be stored (although wind-generated electricity can be stored, if batteries are used), and not all winds can be harnessed to meet the timing of electricity demands. Further, good wind sites are often located in remote locations far from areas of electric power demand (such as cities). Finally, wind resource development may compete with other uses for the land, and those alternative uses may be more highly valued than electricity generation. However, wind turbines can be located on land that is also used for grazing or even farming.
Some more advantages are the electricity generated by the wind does not emit CO2 or leave any waste. Wind is also an infinite resource that cannot be exhausted. A small home wind turbine – when installed properly and in the right location – can cut your reliance on traditional fossil fuel resources. If you install a home wind turbine, you can earn money through the Feed-in Tariff for every kilowatt of electricity you produce, reducing your energy bills. Wind turbines rely on simple mechanical processes. Once the wind turbine is up and running, there are few running costs. Large-scale wind farms can be built at sea to exploit the UK’s abundant offshore wind flow without cluttering the landscape.
Disadvantages of Wind Power
The Energy Saving Trust has concluded that fewer sites than previously thought are suitable for wind technology. Both small- and large-scale wind energy installations may require planning permission – contact your council before you start work. Wind turbine costs are high. A small 1kW roof-mounted turbine can cost up to £3,000. While domestic wind turbines require little maintenance, the inverter is likely to need replacing during the lifetime of the turbine, at a cost of £1,000 to £2,000. The amount of electricity generated is dependent on the speed and direction of the wind. The wind speed itself depends on a number of factors, such as location within the UK, height of the turbine and whether there are any nearby obstructions. Many people dislike the appearance and sound of wind turbines in the landscape, although noise pollution is less significant for micro-turbines. Anti-wind-farm groups argue that wind farms damage habitats and harm birds and marine ecology. Wind is an unpredictable energy source and requires the backup of more-traditional and polluting methods of energy generation.
Wind Energy Farms
Onshore wind turbines are located in areas with adequate wind speeds and in exposed locations free from obstacles like trees or buildings that can interfere with turbine performance. Particularly good wind speeds are found in Scotland, Northern Ireland and Wales and 60% of the UK’s wind resource is in Scotland.
Cost Estimation of Wind Energy UK
By early 2011 the United Kingdom is forecast to reach 10% of its electricity consumption from renewables. The proportion is set to rise to about 30% of renewable power generation by 2020, in line with EU 2020 targets and UK government plans on reducing carbon emissions.
In the generation of wind energy, the cost of generation depends on some factors namely:
- Speed of wind
- Plant Costs
- Financial and Operating Cost.
No single value can be assigned to the cost of wind energy generation unless comparisons with other renewable energy parameters are taken into account.
Wind generation costs can be compared with those of the thermal sources, Biomass, Hydro and Nuclear for electricity generation, using similar procedures and including the cost of operating, maintenance, installation and the nature of technology involved.
Onshore wind Installed costs recent published installed costs for UK wind farms are in the range £1,250/kW to £1,573/kW, with a weighted mean of £1,334/kW. This suggests that Ofgem’s recent estimate of £1,200/kW is on the low side. The generation cost from onshore wind, at £1,300/kW, is just over £108/MWh at a site where the mean wind speed is 6.5m/s, falling to £67/MWh at a site where the mean wind speed is 9m/s. With a “high end” installed cost of £1,600/ kW, generation costs are £104/MWh at 7.25m/s, falling to £72/MWh at 9m/s. At the average capacity factor of 29.4% recorded in 2008, generation costs – at a mid-range capital cost of £1,450/kW – would be around £90/MWh.
Offshore wind although a number of projects were completed during 2009, there is not a large database of project costs. Recent and planned projects have been installed for between £2,000/kW and £4,000/kW. Ernst and Young (2009) used a reference price of £3,200/kW and, with operating costs roughly double those of onshore wind, this suggests that generation costs will also be roughly double. There is a wider range of installed costs, compared with onshore, as there are additional variables that influence the cost, particularly water depth and distance from the shore. A range of costs from £2,500/kW to £3,600/kW encompasses the majority of recently reported costs for European wind farms.
Conclusions
It may be concluded from this analysis that wind energy generation costs, although presently dearer than those of gas, could become more competitive, as there is a strong consensus that fossil fuel prices are likely to rise. Onshore wind is close to being competitive with new coal-fired plant at wind speeds above around 8.5m/s, and higher carbon prices would strengthen its position. Nuclear costs are somewhat uncertain, but it undercuts wind at most wind speeds if it can be built for £2,000/kW. At £3,300/kW, onshore wind is cheaper at wind speeds above around 7.8 m/s (approx. 31% capacity factors), but the application of a risk premium for nuclear would improve the competitive position of wind. Offshore wind currently delivers higher generation costs than the fossil fuel sources, but that could change if installed costs fall with increasing maturity of the industry.
Geothermal power is not a viable large-scale option due to its small range of applicability within the UK. Within the UK geothermal energy is not used for the production of electricity, it is only used as a heat source. In order to use this technology to produce electricity a lot of infrastructure has to be built such as; wells deep enough to provide water which is hot enough to produce electricity, low temperature boilers and insulated pipes to transport the hot water. Furthermore, there are not enough viable locations within the UK to extract how water due to the lack of volcanic activity present.
With a little comparison, the generation cost from new gas-fired plant was around £49/MWh, whilst for coal it was around £69/MWh. Generation costs for proposed new nuclear plant are between £57/MWh and £86/MWh, so therefore we suggest that nuclear and onshore wind prices lie within the same range. Wind is cheaper than coal at wind speeds above 8m/s (at £1,300/kW), or 9m/s (at £1,600/kW). Gas, which currently (2010) tends to set the reference price, is presently cheaper than wind.
Summary
The power generation sector being highly dependent on fossil fuel is causing rapid increase in carbon emissions which intern is leading to global warming and climate change.
In the year 2017 the total CO2 emissions by UK’s energy sector was estimated to be 105Mt, which accounted for 29% of the UK’s total CO2 emissions. Under the climate change bill, the target of UK is to reduce its carbon emission down by 80% of the 1990 emissions by 2050 and according to this by 2020; UK should reduce the carbon emissions by 34% of the 1990 emissions. (Department for Business, Energy & Industrial Strategy, 2018)
In the year 2007, the European Council agreed to put in place targets to ensure that at least 20% of the European Union’s energy will be generated by renewable sources by 2020. The United Kingdom aims to produce 15% of their energy from renewable sources by the year 2020 in a cost-effective way. (Department of Energy & Climate Change, 2013)
Achievement of these targets will be challenging and will require significant research and investments in renewable technologies for power generation.
There are many renewable technologies available, careful assessment of each technology must be done before investing in it. The selected technology must reduce the emissions of greenhouse gas and apart from that other factors like lower capital investment, greater revenues, reduction in energy bills and efficiency of the technology must also be considered.
In this report, we assess different renewable technologies to generate 2 GW electricity in UK and suggest the best technology or combination of technologies available.
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