Global warming is now a fact accepted by the majority of scientists. Debate rages over whether it is a natural phenomenon or man-made due to the greenhouse effect. But the consensus is that we cannot wait for the answer before we do something about it. Greenhouse gas emissions must be cut, and one of the most significant greenhouse gasses is carbon dioxide from the burning of fossil fuel.
The carbon dioxide in fossil fuels was removed from the atmosphere millions of years ago by plants and animals, which nature then turned into coal, gas and oil. By burning those fuels now we are returning that carbon dioxide to the atmosphere and, so the theory goes, causing it to trap more of the sun's energy and thus heat up.
Renewable energy sources such as wind, wave, solar and biomass either emit no carbon dioxide or recycle what is already in the atmosphere, they are not increasing the burden of the gas in the atmosphere.
We have accepted the effect our existing sources of power have on the landscape - pylons, power stations, coal mines and oil terminals - but people are not so accepting of the new technologies introduced to tackle the issue. Each option has its own detractors and supporters
Why Should I Care?
Large-scale, rather than personal scale, renewable energy options are likely to be based away from main centres of population – potentially in areas we value for their tranquil and natural scenic qualities. New industries could create much-needed jobs in rural areas, but the corollary can be intrusions into the landscape, heavy lorries on country lanes, transport of hazardous materials near homes and an increased potential for dangerous accidents.
Wind farms are the most controversial source of renewable energy and, so far , the most popular. Energy company United Utilities says a single two megawatt turbine can generate enough electricity for 1,200 homes with no emissions but opposition groups spring up wherever a new wind energy development is planned.
Windfarms are a controversial source of renewable energy
Pro-wind campaigners dismiss objections as merely nimbyism. On a small scale wind turbines can provide electricity in remote locations where they are the size of a telegraph pole and do not impinge on the landscape. Commercial scale turbines reach 50 to 150m into the air when the blades are at their highest. They are usually painted a matt grey to minimise visual intrusion but are situated in dense clusters. Wind turbines out at sea could be a lot taller, but some objectors are just not in touch with reality with the heights they quote.
Objections to wind farms are usually centred around their impact on the landscape and the noise they create, a whooshing sound as the blades rotate. Opponents also claim they are not reliable as they do not work in very low or very high wind conditions, but Britain is the windiest country in Europe and no-one is suggesting we generate all our power in this way.
Other objections include their effect on wildlife, particularly killing birds who fly into them. The Royal Society for the Protection of Birds is supportive of alternative energies but says each proposed site should be viewed on its own merits and they should be away from sensitive areas for wildlife.
One of the highest profile objectors to wind farms is Dr David Bellamy, the internationally known botanist and environmental campaigner. He claims wind farms are a blot on the landscape and do not live up to the claims made for them.
Burning crops as fuel releases only the carbon dioxide those crops took in whilst growing, which is then taken up again by the next crop. This constant recycling is known as a carbon-neutral system.
Farmers across the country are being persuaded to sign up to producing biomass, which can be used to fuel large scale power stations, smaller district heating systems and individual boilers for schools, industrial sites and homes.
One significant factor in this market is the transport costs of the fuel, which needs to be produced within a short radius of where it is used.
Crops which can be used in this way include willow, miscanthus or elephant grass, and residue from oil seed rape production. Bio-diesel and bio-ethanol can also be manufactured from crops.
Opposition to construction of plants for any of these processes would be local. There appears to be no organised objection to this type of energy production.
Solar power can be used to generate electricity through photo-voltaic cells or more directly to heat water for hot water and heating systems. In this country the water heating option is the most effective and is commercially available.
Water is pumped from the tank through solar panels on the roof, where it absorbs heat from the sun, and back into the tank. This considerably reduces the energy needed to warm the water to usable temperatures. Some systems use a solar-powered pump.
Neighbours may not like the look of solar panels on your roof, but they are no worse than a satellite dish!
Underground the Earth is hot, the deeper you go the hotter it is. If you drill a borehole into the ground and pump water into it that water will come up warmer than when it went down. Alternatively large plants can utilise underground supplies of hot water. This system is very popular in Iceland and 80 per cent of Reykjavik's energy comes from geothermal sources. In the UK there are very few examples of geothermal energy being used, although Northumberland National Park Authority's Sustainable Development Fund has supported a number of small business ventures adopting these techniques.
Wave and Tide Power
Occasional lulls in wind may stop wind turbines working but the waves and tides are always there. So far efforts to develop reliable electricity generation from wave power have not been very successful and schemes also come across the objections of people who want to see alternative energies developed, but somewhere else.
The next decade could see the introduction of commercially viable wave power technology, but it would have an impact on marine life, shipping and possibly on the view from shore.
Tidal power is also not yet available. Planned schemes included barrages across several major rivers but these met huge objections because the barrage cuts off the river from its estuary, having a profound effect on wildlife, sediment flow and navigation. Other options include developing something like a wind turbine which works under water with the ebb and flow of the tide, but it is not yet available.
The Nuclear Option
Nuclear energy causes no carbon emissions, making it a solution to the greenhouse gas problem. In place of that there are all the issues surrounding its safety, the long term storage of nuclear waste and the potential for catastrophic failures. Britain has been in a programme of closing down its nuclear power stations but now the possibility of building a new generation of reactors has raised its head. The political debate around this issue is in its infancy and will doubtless run and run. With nuclear energy the size of the backyard is enormous.
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