Renewable Energy

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Of all the energy consumed in the United Kingdom each year, around 34% is used by cars, buses and lorries. Factories, offices and shops use 24%, while 28% is used in people's homes. By far the most energy we use comes from fossil fuels gas, oil and coal. These fossil fuels are 'non-renewable' - the environment has taken millions of years to make them and we cannot make them ourselves. Once they're gone, they're gone. And the faster we use them, the faster they will run out!

Wind Power
Passive Renewable Energy
Solar Power Cells

No-one is certain what the long-term effects of climate change caused by the greenhouse effect will be, but current fore casts suggest the Earth will warm by between one and 3.5 degrees centigrade over the next 100 years.

The 1990s were the warmest decade on record, according to researchers. As a result, glaciers world-wide are retreating and sea levels are rising, according to experts from the UK Climate Change Impacts Programme (UKCIP). In the United Kingdom, temperatures are expected to rise by between 0.1°C and 0.3°C Celsius every 10 years.That could easily add up to 1.5°C over the next 50 years. This may not seem much, but experts suggest that it could cause up to 10% more rain to fall every year.

In the north of England, it is thought that this could mean wetter weather all year round, while in the south, the extra rain would probably fall mostly in the winter time. Effects may include flooding, damaged house foundations due to soil crosion, and possible risks to health from tropical diseases, according to a World Health Organisation report on Climate Change and Human Health. The Gulf Stream is a flow of warm water which travels across the Atlantic Ocean to make the climate in Britain milder than it would otherwise be. For instance,although Russia is the same distance from the polar ice caps as the United Kingdom, it experiences far colder winters than we do. But continued climate change could change the Gulf Stream's course. If this happened, our winters would be much colder with a lot more snow and ice.

So, despite it's name, the global warming effect could well mean a chilly future for us here in the UK

So, what causes the greenhouse effect? Producing energy from fossil fuels creates a variety of waste gases, which have a serious effect on our environment. One of the most significant of these waste gases is carbon dioxide (CO2). In the UK alone, a total of around 158.3 million tonnes of carbon are emitted every year. The atmosphere naturally contains a certain amount of carbon dioxide. But burning coal and oil to generate energy adds to it, and causes an increase in the amount of heat that the Earth's atmosphere retains, which is known as "the greenhouse effect".

Burning fossil fuels releases other chemicals into the atmosphere, including sulphur dioxide. This chemical can form acid rain, which harms wildlife, plants and even buildings. Other chemicals, like nitrous oxide and methane, work like carbon dioxide and are also believed to contribute to global warming.

All the chemicals we produce by burning fossil fuels are released into the air we breathe, and so can affect our health.

Wind Power

First, some science! Inside the sun, matter is converted directly into energy by the process of nuclear fusion, where small amounts of matter yield an enormous amount of energy .This potential is illustrated by Einstein's famous law
E=mc2, where 'E' is the amount of energy created, 'm' is the mass of matter destroyed and 'c' is 2 x 108 metres per second - the speed of light.

The sun's energy takes about eight minutes to cover its 93 million mile journey to reach us on Earth. In fact, the total energy reaching us from the sun is about 10,000 times the current global energy demand!

As this energy heats up the surface of the Earth, it causes air to move around the planet, creating the wind - itself a valuable energy source. As of Spring 2001, there were 62 projects in the UK with 852 turbines producing 409 megawatts of power - that's enough to provide electricity for nearly 260,000 homes. In April 2001, the Government announced the release of eighteen potential sea bed sites for new offshore wind farms.

Some wind energy is harnessed in the oceans, giving us another source of energy - wave power.

Four-fifths of the sun's energy falls on the sea. Ocean evaporation causes rain to fall on the land, creating natural and man-made lakes which can be harnessed to create hydro-electricity.

The remaining fifth, which falls on land, is still about 2,000 times greater than the total world energy demand. This solar energy can be captured using a variety of technologies.

Passive Solar Renewable Energy Back to top

Passive Solar - which involves designing buildings so that they collect and use the sun's warmth.

This may sound ultra-modern, but it's an ancient technique used by early Greek and Roman builders, as well as by people living in the Pueblo villages in the American south-west and the Incas in South America. Forms of solar architecture were also developed by Muslim architects, who used the minarets of mosques as solar chimneys.

The discovery and exploitation of cheap fossil fuels made solar design a thing of the past - until now. Steep rises in oil prices, and the realisation that fossil fuels arer unning out fast, mean that the sun is once again seen as an important source of energy.

Passive solar design competes very well in terms of cost with conventional energy sources. Up to 70% of a building's energy needs can be provided through design.

Large glass windows or conservatories on south-facing surfaces can exploit large amounts of free energy. As the costs approach those of conventional building cladding or roofing materials, solar power could allow buildings to generate their own electricity - selling it to the National Grid when they produce more than they can use, and buying electricity back when they need more than they can produce.

Solar Power Cells Back to top

The 'Photovoltaic effect' - this means generating electricity from sunlight. The real breakthrough in photovoltaic research came in the 1950s. Bell Laboratories in the USA discovered that silicon - the second most common element on Earth- was sensitive to light and generated a substantial voltage when treated with certain impurities. In the late 1950s, NASA made a giant leap for humankind when it installed a 108- cell photovoltaic array on America's first satellite,Vanguard One.

Since then, the photovoltaic effect, or PV, has become well-established. It is used to provide energy for remote industrial equipment for telecommunications, and to bring power to some people in developing countries who have no access to electricity. These uses for photo-voltaics tend to occur where there is lots of sunlight, as well as heat. You may think this means PV needs tropical sunlight, but, it actually works very well in bright daylight in northern Europe, too.

Photovoltaics are now a real alternative, particularly in remote places where it can compete with the higher installation costs of long links to conventional electricity supplies or expensive diesel generators. Photovoltaics are becoming increasingly common through being integrated into the design of buildings.Photovoltaic generators operate with no moving parts, noise or pollution, making them the best renewable energy source for use in urban areas.

In the UK, there are at present only a handful of photovoltaic roofs, in contrast to countries such as Germany where there are over 1,000 already in operation, with plans for many more.

So, where is renewable energy now?

Only a very small amount of the energy used in this country comes from what are called 'renewable' sources, such as
wood, straw, sewage sludge, the sun, wind farms, waves and rivers.These do not cause as manyproblems for our environment.

Renewable energy sources in the UK currently generate almost 5% of the our total electricity supply. New targets set out by the Government aim to boost the generation of electricity from renewables to 10% by 2010

This page is taken from Derbyshire County Council 'Smartliving' pages and comes with the following disclaimer

'The contents of Smartliving are drawn from a wide variety of sources. While we have made every effort to ensure accuracy, DCC will not be held responsible for any errors in this publication. Views expressed, or mention of any organisation in Smartliving should not necessarily be
regarded as an indication of Derbyshire County Council's official policy or support.'