Alternative energy sources are renewable sources of energy which include wind power, tidal energy and nuclear power. Energy demands are extremely likely to increase in the future due to rapid global population growth, the world population now nearly seven billion may rise to 16 billion by 2100 and predicted by the UN. NIC are industrialising at large demanding high energy needs, meanwhile its population’s quality of life and standard of living increase as better paid and well educated and skilled jobs become available. Bangalore, India; is a hub for IT specialist jobs where people are able to get high paid jobs, this allows them to consume high energy consumption products such as cars, washing machines. They have the money to travel long haul destinations, tourist numbers from China have staggered over the last couple of years. Governments need to respond to this demand by finding alternative sources to fossil fuels and to have more of an energy mix.
In the UK there to meet future energy demands by increasing our wind energy and developing tidal barrages to harness tidal energy in River Estuaries. The estuary of the River Severn in south-west Britain is notable for its great tidal range of almost 15 metres. There is undoubtedly tremendous potential to develop a tidal power station in the Severn Estuary. The proposal to develop tidal energy along the River Severn has been met with controversy. The Severn Barrage would have a design life of 120 years, much greater than that of a conventional power station, nevertheless it has very high capital cost, estimated at £14 billion over 15 years of construction. A reliable supply of electricity which produces zero emissions of carbon dioxide and other green house gases. The installed capacity of the barrage would be 8640 GW over four times the size of a large coal or oil fired power station.
However, the barrage will only generate for only eight hours a day and thus its output of 17000GWh per year will be equivalent to less than two conventional power stations. The Severn Barrage is thought to create employment, mainly in construction phase, when up to 40,000 people might be required but also operational phase both directly and in the developments arising from barrage’s attraction to tourist. This may allow to skilled workforce from the universities nearby such as Cardiff to stay so the surrounding areas don’t have brain drain. As people come in, the city will improve economically and socially and become a destination city as a tourist hotspot, creating a positive multiplier effect, however, the construction jobs are not permanent, as soon as the construction of the stations are over, many will lose their jobs, similarly, as the barrages are put in to place, shipping is affected this has a knock on effect on employment and deprivation of the area.
The Severn Estuary has four major ports as well as many smaller ports, together these ports handle 18 million tonnes of cargo per year and provide 15,000 jobs, if shipping is affected and ports need to close down there will be lost of employment and deprivation in these areas. Some sources say flooding in the Severn Estuary can be controlled and prevented, meanwhile others say that in fact the sediments slit up the river making it much smaller hence increasing the flow of river in a small compressed space. It could lead to physical changes at the estuary because of the reduced tidal range, as it affects the landscape morphology and the sedimentary processes. Salt marshes are estimated to be reduced by 40% and mudflats by 5%; transitional grassland will increase by 6%. The reduced tidal range and tidal currents upstream of the barrage would create safer conditions for sailing.
This could lead to the developments of marinas, employment and housing to service the sailing sector. On the other hand, Bristol has plans for a new dock to handle the next generation of cargo ship of up to 130,000 tonnes and 16m draught. The reduced tidal range may pose problems for large vessels entering the port of Bristol itself; pumping might be required to raise vessels to the height of the water in the enclosed docks; a slow and expensive process. The barrage could be very hazardous to marine life in the sea hence environmentally unfriendly and unsustainable as it could affect breeding patterns of birds; there are five bird species of international importance and the barrage could affect them immensely. Marine life, such as fishes; salmon can be killed in the sluices and turbines, and discouraged from migrating by the presence of the barrage. The UK environmental Agency has predicted high mortality rates for salmon, sea trout and shad.
Harnessing the kinetic energy of the wind and converting it to mechanical energy and electricity is one of the most rapidly growing, cost effective and proven renewable energy technologies. By 2012, 22 countries had installations of more than 1000 megawatts, compared with just 11 countries in 2006. Both China and the USA have over 50,000 MW of installed wind energy, and total world wind energy installation amounted to over 250,000 MW in 2012. This represents a ten-folded increase since 2001, yet wind energy still amounts to only 3% of total world electricity production. Until recently most wind turbines have been sited on land, either individually or grouped together in wind farms. The pace of technological development within the wind energy sector has been rapid and wind turbine power units are increasingly efficient.
However, there are different views to the proposition, while some welcome the development of wind farms, other resist them. Wind energy us a renewable source of energy which produces no carbon or sulphur dioxide emissions and replaces generation from conventional power stations. Wind energy thus does not contribute to green house effect which is thought to be causing climate change. The UK Government estimates that the net savings from wind power in 2010 were 6 million tonnes of carbon dioxide. This takes account of the effect of fossil fuel power used for back-up during times that wind power was not available. Although wind turbines can be very tall each takes up only a small plot of land. This means that the land below can still be used for agriculture. Nevertheless, some people find it visually unattractive, spoiling the countryside and altering its natural form. Wind turbines are noisy. A researcher from the Daily Telegraph recorded it to be as loud as a busy main road, however technological development means many modern turbines have no gearbox, resulting in reduced noise.
Wind turbines can create turbulence and vibrations. Acoustic scientists estimate a fifth of Britain’s wind farms generate a low frequency hum that can be audible for more than a km and can be very intrusive. The pulsating sound, a phenomenon called amplitude modulation, is probably caused by turbine blades striking patches of turbulent air. Wind turbines are available in a wide variety of sizes, which means that users can range from single households and businesses to vast wind farms supplying whole regions. Suitable sites for wind turbines are often in remote locations, distant from areas of demand for electricity. Thus there is an additional expense in connecting to the National Grid so the electricity can be distributed to the appropriate areas, and obtrusive pylons and power lines cross the countryside. Wind energy can bring wider economic benefits for a country. For example, there are an increasing number of companies around the UK involved in manufacturing turbine components and installing, operating and maintaining. Decommissioning of wind farms is straight forward and leaves no toxic waste residues or environmental damage; however wind turbines kill birds, especially at higher rotation speeds when the turbine blades can become invisible.
In conclusion, the world cannot carry on as business as usual, the risks, impacts and danger is very high and could lead to the destruction of nations as they fight over the last resources of fossil fuel or are endangered by the impact of global warming. Thus an alternative energy source needs to acquired and put into use so that the world can function as normal without economic decline and standards of living falling, as well as to be able to look forward to a sustainable future, governments and nations need to look into diversifying their energy sources, a mix of renewable energy sources will help the country become independent of fossil fuels and can lead to a better sustainable future for the generations to come.