Friday, 4 February 2011

Energy Sources

So far this week in my Geography lesson’s we have been presenting our group presentations on the different types of energy. I found it quite hard to take detailed notes on some of the energy sources and so I am going to try and quickly summarise each energy source…….
Wind Energy: RENEWABLE
·         Suitable areas are those that have an average wind speed of 25 kilometres per hour. This means that coastal areas, on top of hills and plains are often the best places to develop wind farms as they often experience stronger winds more frequently.
·         It is the most developed form of renewable energy and is used in many countries. In this country this energy source is mainly used to supply electricity to remote locations.
·         In this country there are currently 3,153 turbines and there an additional 30 new wind farms under construction.
·         At current levels of development wind farms are expected to produce 4.6% of the electricity we will use in the UK this year BUT they are unreliable. For example in December of last year they only produced 0.2% of the electricity we produced which is only 2.43% of their capacity. Due to this countries, like Australia, often build wind farms in conjunction with other renewable energy source plants.
·         However they are not popular as they don’t look nice, are noisy and are unsafe for birds. Many people in this country have the NIMBY (not in my backyard) attitude towards wind turbines – one of the case studies on the film The Age of Stupid perfectly presents this attitude (it is well worth watching!). Space is an issue as the turbines themselves take up a lot of room and roads need to be built so that they can be accessed to be serviced. There are also some questions surrounding the production of the magnets needed to build efficient turbines but for more on this see the previous blog post (Are turbines really as green as we think they are?).
·         On the other hand, they produce free green energy and in terms of start-up costs, due to the levels of development, it is slightly lower than that of other renewable energy sources.
Personally I don’t think that wind farms will be able to provide a reliable and strong enough source of energy to power this country. This is partly because it is a rather unreliable source of energy and because, due to the strong opposition, it would be extremely hard to build enough turbines to allow us to generate a substantial amount of electricity from this source. However some areas in the country, especially the west coast and in Scotland, experience relatively frequently strong winds and therefore I believe that turbines should be built there so that we can utilise this energy source and use it to contribute to our energy mix.
Natural Gas: FOSSIL FUEL
·         Although it is considered to be a fossil fuel it is ‘cleaner’ than oil and coal. Burning natural gas produces 30% less carbon dioxide than oil and 45% less than coal.
·         It’s a finite resource and it is estimated that supplies will run out by 2085.
·         Natural gas reserves can be found in 50 countries around the world but the largest reserves of this resource are in Russia and the Middle East
·         It is essentially formed in the same way as oil (natural gas it formed at high temperatures and oil and lower temperatures) and this means that it is extracted in a similar way.
·         Before natural gas can be used it has to be refined to remove impurities from it. This process results in other gases escaping into the atmosphere.
·         After it has been refined, natural gas has multiple uses – residential (heating), commercial (fuel-cell energy), and industrial (incineration).
·         Natural Gas industry has long been recognised for trying to reduce the environmental impact that producing this energy source creates. A company called Statoil extract natural gas from the North Sea and they have developed a method of capturing and storing the carbon impurities that are in natural gas
·         However, if a spill or leakage was to happen then the environmental impacts could be massive as a considerable amount of methane would be released into the atmosphere
·         As natural gas is more environmentally friendly than oil and coal it is likely that over the next few years this energy source will be utilised more and more. This energy source is also being developed more to try and make it more environmentally sustainable; at present researchers are trying to find methods of combining it with a specially designed panel that allows a heat-producing reaction to occur which then can be used to heat water.
It will be impossible for us to switch from using fossil fuels to renewable energy sources overnight and so, whilst further development of renewables takes place, I think that natural gas could be used more to reduce the world’s dependency on oil and coal. Although all fossil fuels release potentially harmful gases into the atmosphere; natural gas is the most environmentally friendly one out of them but the use of this source will need to be managed to minimise the impact it has on the environment and to try and make the reserves of it last as long as possible.
·         It is estimated that we will reach peak oil production in 10 years and that oil reserves will run out within 40 years. This is potentially a huge problem as we rely so heavily on oil as it is linked to most of the items we use every day.
·         Oil drilling is permitted in 99% of the world’s oceans. Oil drilling negatively impacts on the nearby ecosystems and sea life. For example, the laser guns that are used to detect oil are believed to cause the loss of hearing, amongst other damage, in marine life such as whales who rely greatly on this sense. The burning of oil also releases a large amount of carbon dioxide into the atmosphere.
·         An ever increasing demand for oil has led to companies exploring deep water oil. This is more risky and oil spills and blowouts become more likely. The BP oil spill last year demonstrates what can happen if something goes wrong. Many people wonder whether it is really worth the risk……
-          17 workers died
-          75 000 barrels of oil leaked out of the well every day which totalled to 145 million gallons of oil before the well was sealed.
-          This oil travelled 40 miles and had huge impacts on the local environment and industry which relies on fishing
There is a very informative National Geographic article on the oil spill – this is the link if anyone is interested and wants to know this issue
·         The film The Age of Stupid includes a case study that outlines the impacts the oil industry is having on developing countries like Nigeria. Unfortunately they are mainly negative ones as pollution has affected fish stocks and water supplies and promises by oil companies to build schools and hospitals are not carried through and in this case this has increased poverty in the area.
·         Recently BP signed a deal with a Russian Oil Company to explore the possibility of oil in the Artic
The incident last year involving the BP oil rig in the Gulf of Mexico highlighted the impacts that this industry can have on the environment. As the demand for oil increases the risk of something like this happening again is only going to increase too. I think that we have become too dependent on oil as a resource and source of energy and so it is going to be very hard to stop using it. In the near future I think it will be very unlikely that we will stop using oil completely especially when companies, like BP, are thinking about investigating the Artic in search of oil. Although there maybe oil there I think the money and time would be much better spent developing renewable energy sources as someday our oil reserves are likely to run out and, at present, we will not be able to rely on renewable energy to supply electricity and energy to the same quantities that we currently consume.
·         In terms of development it is 10 years behind wind energy and is the least developed source of renewable energy and at present can only be implemented on a small scale.
·         In 2007 the EMEC research centre was set up on the Orkney Islands to try and develop more effective ways of capturing wave energy.
·         Wave power is the concentrated wind energy that is stored in the waves and so wave plants are often built in conjunction with wind farms.
·         West coast of the UK is a good place to try and capture this form of renewable energy as it has a long fetch. Places like Norway are also ideal as the fjords condense and concentrate wave energy and so make the waves stronger and so more energy can be generated.
·         Suitable areas are those that have a yearly average of over 15kW per metre as this enables the electricity to be generated at competitive prices.
·         It is predicted that at current levels of development 15%-20% of the UK’s electricity demand could be supplied by this source.
·         Australia uses the floating buoy method which involves using submersed air filled balloons which move with the water to pump water to shore for electricity generation.
·         The Limpet device was installed in 2004. A gully was excavated into the shoreline so that a concrete chamber could be built to trap waves and then force the water back through turbines.
·         In 2007 four floating sea snakes were built and placed off the Orkney Islands. They work by generating electricity when the motion of the waves moves the hinged joints that connect the tube sections. This project cost £10 million and provides power for 3000 homes.
·         The Wave Hub was built in Cornwall in 2007. The project involved an onshore substation connected to electrical equipment on the seabed 10 miles from shore via a sea-cable. Wave Hub has the ability to provide power for 7 500 homes which saves around 300,000 tonnes of carbon dioxide every 25 years.
·         However the construction of such projects damages tidal basins and so they are unpopular with surfers. This then has a knock on effect on the local economy as, areas like Cornwall, are reliant on the income created by tourism and the surfers who visit areas with big waves. Also, at present, the start-costs are very high.
·         On the other hand it is considered to be safer for sea birds than turbines and they do not impact on marine growth as they move with the water not against it.
With further development I think that wave energy could generate a lot of energy for some countries like the UK, Norway, Hawaii and Australia as they have some of the perfect conditions to enable enough energy to be captured to make it financially viable. At present there are lots of different methods that can be used to generate wave energy and I am unsure on what one I think is best as I think it depends on the area at which it is going to be built. The sea snakes seem to have the least amount of impact marine growth and sea life as they move with the water and not a lot of construction has to take place on the sea bed but on the other hand, in an area that it used for shipping they may not be the best method. The one thing that really stood out for me was the fact that wave plants are often built in conjunction with wind farms and as I am learning more and more about the different sources of energy I think that perhaps this is the way forward in terms of energy production as the renewable energy sources are not that reliable and so perhaps it would be most sustainable to invest in and develop a range of sources instead of just focusing on one.
Solar Power: RENEWABLE
·         In 2008 solar power contributed to only 0.02% of the world’s energy use. This is partly because the photovoltaic cells that are commonly used only harness 15% of the sunlight’s energy.
·         The best places to develop solar energy are tropical areas or deserts. The UK receives 50% of the sunlight per square foot of that that countries on the equator receive which means that this energy source could be used in the UK.
·         PV converts sunlight into energy whilst CPS focuses light into a strong beam which is then used to heat water. Solar furnaces use mirrors to direct the energy to a power tower. This method saves 7000 tonnes of carbon dioxide from entering the atmosphere and can generate enough energy to power 4000 homes.
·         Spain uses solar energy a lot – the PS20 tower in Seville has the potential to generate 20MW of energy. California also utilises this source of energy – SEGS.
·         Traditionally in Kenya, kerosene lamps were used as a source of lamp but there is a lot of health risks associated with using kerosene. Solar power is gradually starting to replace kerosene as the source of energy. In remote locations, like villages in Kenya, solar power can provide a reliable source of energy and it means that the villages do not have to be connected to a national grid
·         Solar energy is a very green form of renewable energy but it has high initial start- up costs if you are trying to develop it in a commercial scale.  It is only cost effective in sunny areas and only works during the day which means some areas are not suitable and that the amount of energy it can generate will vary over the course of a year.
In terms of developing it in the UK the south east coast would be a good place as this area experiences the warmest and sunniest weather. I don’t think though, due to our climate, that solar energy will be able to provide anything more than a small proportion of our energy mix. However in countries like Kenya I think that it is a great alternative to using Kerosene lamps and so I personally think that the use of this form of renewable energy should be developed and encouraged in LEDC’s that are located in more tropical areas as it is a good way of providing electricity to remote and isolated settlements.
Hydroelectric Power (HEP): RENEWABLE
·         Hydroelectric power is the production of power by using the gravitational force of falling or flowing water.
·         It currently produces 97% of all the renewable energy in the world and produces 3% of the electricity we generate in the UK.
·         It doesn’t use any form of fuel and the reservoirs that are built as part of the dams can generate their own revenue as they are often used for leisure activities.
·         However the dams are very large and very costly to build and can cause fragmentation of habitats and siltation which can lead to increased flooding in some areas. Dam failures can also occur which can lead to disastrous floods.
·         The Three Gorges dam – At present has a capacity of 18,200 MW and by 2012 this is expected to rise to 22,500 MW. It cost $26 billion to construct. It is believed to have caused many earthquakes and it 2010 it was estimated that around 97 landslides were provoked by the construction of this dam.
·         Tummel HEP in Scotland- Consists of 9 stations which have a capacity of 245MW. This means that they could power 850,000 homes.
At present HEP produces the most amount of energy in the world out of all of the renewables and this means that it is going to play an important role in a greener future. However the building of the dams used to capture HEP are believed to have lots of negative environmental impacts and so the question is, is this the best renewable energy source to utilise? In terms of providing energy for the UK I think that there are more suitable sources of renewable energy to exploit. However, HEP could still provide a proportion of the energy we consume and contribute to our energy mix especially if the development of projects in Scotland continues.
Tidal Energy: RENEWABLE
·         Tidal energy has the potential to supply 20% of the electricity we consume
·         Many people get confused between tidal energy and wave energy but they are very different as tidal energy is produced by trapping water and, when the tide turns, pressuring it through turbines.
·         This energy source is a bit more predictable than the other renewables as tides can be predicted. However the energy source can only be utilised for around 10 hours every day.
·         The La Rance barrage in France was built in the 1960’s and 330 metres long. It produces 4% of the electricity used in Brittany. Since it was built in the 1960’s very little maintenance work has had to be done on the barrage. This demonstrates that, although the start-up costs are very high (estimated cost of £30million to build the Severn Barrage), once built very little money has to be spent on it and that they last for a very long time.
·         The future of the development of tidal energy in the UK is uncertain as the plans for the Severn Barrage were recently scrapped (see blog post ‘Current Local Energy issues’ to learn more).
·         The environmental issues surrounding tidal energy are that the building of barrages can destroy mudflats which migratory birds rely on. Also they disturb fish migratory patterns. Barrages can increase erosion in some locations and siltation in others and therefore increase the risk of flooding.
The scrapping of the Severn Barrage is likely to have huge knock effects of the development of tidal energy in the UK. I think that the Severn Barrage would have been great way of developing our renewable energy production as the barrage had the potential to produce a lot of renewable energy for the UK as the Severn Estuary has a tidal range of 13 metres which is the second largest in the world. The scrapping of the Severn Estuary is a very controversial issue and personally I think that the government should not have been so hasty in their decision to scrap it. Although the barrage would have had some negative impacts on the environment, a similar project has been very successful in France and perhaps a compromise could have been found which involved the proposed size of the barrage being reduced so that it didn’t stretch across the entire width of Severn Estuary.
Geothermal: RENEWABLE
·         Geothermal energy is the thermal energy stored within the ground. This thermal energy is created by volcanic activity, radioactive decay and absorbed solar energy.
·         There are only a handful of locations across the world that have the conditions required to produce a substantial amount of geothermal energy in a finically viable way.
·         Geothermal energy can be utilised in two ways. Often water is pumped down into the hot rocks which then heat up the water. Sometimes this water is pumped straight back to homes to be used for heating. The compressed steam that is created by the heating of the water can also be used to generate energy by using it to turn turbines and therefore generate electricity.
·         It is often quite hard to find suitable areas to try and capture this energy source as, due to the fact you have to drill down quite deep into the rocks, soft rock areas are required.
·         No fuel is needed to run the plants and they don’t have to be very big which means they are a very green source of energy. It is also a very reliable source of energy. However start-up costs are very high and so are maintence costs as it causes corrosion. They also have a 20% failure rate.
·         Iceland produces the most geothermal energy and Iceland sources 25% of the energy they consume from geothermal energy. 90% of heating comes from geothermal energy as well. Iceland is Europe’s largest producer of bananas as they can generate the heat required to grow them in greenhouses from geothermal energy.
·         There is a hot rocks project on Dartmoor which helps to produce hot water but this project was very expensive.
·         In 2010 the Eden project was given permission to build a hot rocks geothermal plant with the capacity of 3-4MW.
The hot rocks projects that are currently being developed in the UK have the potential to generate quite a bit of renewable energy that will contribute to our energy mix. However, we will never be able to rely as heavily on geothermal energy as Iceland, for example, as we don’t have the right conditions to do so. Despite this fact I still think that it is worth developing this source of energy as it could provide heating and hot water for local people.
·         Russia, China and the USA have the largest coal reserves in the world.
·         Coal can be mined in two ways – shafting or surface mining
·         Mining is very dangerous but it a very big industry. 40% of the world’s coal is produced in China were they have 5 million workers involved in the industry. However, an estimated, 20,000 coal miners die in China each year.
·         Electricity is generated when the coal is burned and used to heat water to produce steam which is used to turn turbines.
·         A typical coal-fired power station generates 3,700,000 tons of carbon dioxide a year which is the equivalent of cutting down 161 million trees.
·         The burning of coal produces carbon dioxide, methane and sulphur dioxide which all contribute towards acid rain. Water pollution is often caused which damages ecosystems.
·         The coal industry used to be massive in the UK but after the mines were privatised this industry started to decline. Another reason for the decline was that the remainder of our coal supplies are so deep down that they cannot be extracted at competitive prices and so it is cheaper to import coal from abroad.
·         Most of the coal-fired power stations in the UK have since been turned into gas and nuclear power plants.
Although the amount of coal we are using is reducing we still import quite a bit from other countries. The move to convert our coal-fired power stations into gas and nuclear power plants was, in my opinion, a positive one as it has meant that we are less dependent on coal and are using other, slightly more, environmentally friendly sources of energy.
Uranium/Nuclear Energy:
·         Uranium is used in nuclear power.
·         50% of the world’s reserves of uranium are in Canada, Australia and Kazakhstan.
·         Although it is a fossil fuel it doesn’t produce a lot of carbon dioxide (produces depleted uranium instead). Also the reserves of it are predicted to last a lot longer that oil reserves – it is predicted that they could last for up to 60 years if demand for it stays at the present level.
·         In the UK the government has recently agreed to develop nuclear energy in the UK. The closest one to us is Hinkley Point (see the blog post ‘Current Energy Issues’ for more details on the proposed Hinkley C).
·         The largest issue associated with nuclear power is the dangers linked to producing it and how we dispose of the radioactive waste. If something was to go wrong then the affects would be vast – Chernobyl Disaster of the 26th April 1986
Although I believe that nuclear power, if managed properly, is a better option than relying on oil and coal to produce energy; I personally believe that money would have be better spent trying to develop the plans for capturing tidal energy in the Severn Estuary. However, in the near future, I think that nuclear energy is likely to contribute a large proportion to our energy mix.

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