Environment Watch

Saving Energy

Why Saving Energy Helps Combat Climate Change

Global Warming is caused by the increase of certain gases in the atmosphere. These gases are commonly referred to as greenhouse gases. At present (2006) the main culprit is carbon dioxide (CO2). Once CO2 levels have been reduced, the next target will be methane (CH4). Methane is a greenhouse gas with a global warming potential over 100 years of 23 (IPCC Third Assessment Report) i.e. when averaged over 100 years each kg of CH4 warms the earth 23 times as much as the same mass of CO2. We will only consider methods of reducing CO2 as Carbon Dioxide is currently the main greenhouse gas.

The most common forms of energy that is used domestically are:

  • Electricity for light, heat, transportation and domestic appliances
  • Gas for heat and small amount of light and transportation
  • Oil for heat and transportation
  • Coal for heat
  • Wood for heat


Of the above list, electricity is the only type of energy that has to be generated from another source. In order to generate electricity, a turbine has to be rotated in order to convert one form of energy to electricity. These sources of energy that can turn a turbine, and thus be converted into electricity include:

  • Steam which is created by:
    • Burning coal
    • Burning oil
    • Burning gas
    • Heat from a nuclear reaction
  • Wind
  • Water

If all our electricity was generated by wind or water power, there would be no need to reduce the amount of electricity used as the process of generating the electricity does not create any CO2. Similarly, if all our electricity was generated by nuclear power, there would be no need to reduce the amount of electricity used as the process of generating the electricity does not create any CO2 but it does create hazardous radioactive waste.

But, the reality is that most electricity is generated from steam that is heated by burning coal, oil and gas. Burning most fuels (e.g. wood, waste, oil, gas and coal) results in heat and CO2. So, if we reduce the electricity we use, we reduce the amount of CO2 created by the power station and, by reducing the CO2 created, help to combat global warming.

Gas, Oil and Coal

These are fossil fuels. By fossil fuel we mean a substance that has taken millions of years (often hundreds of millions of years) to create. Although they look different - coal is solid, oil is a liquid and gas is a gas - the basic by-product of creating heat is CO2. So, if we reduce the fossil fuels we burn, we reduce the amount of CO2 created and, by reducing the CO2 created, help to combat global warming.


This is a biomass fuel. In energy production and industry, biomass refers to living and recently living biological material which can be used as fuel. It excludes organic material which has been transformed by geological processes into substances such as coal or petroleum (oil). The "caloric content" (energy content combustion) of firewood depends mainly on how dry it is. "Green" wood is about 10 MJ/kg (megajoule per kilogram), air-seasoned wood about 16 MJ/kg, while kiln dried wood is about 19 to 20 MJ/kg. The potential heat content per kilogram of wood is roughly equal for all wood varieties.

It is not worth trying to reduce wood burning in order to reduce CO2 emissions. When living, the wood was converting atmospheric carbon dioxide to carbohydrates in its cell structure. If the dead wood was allowed to decay naturally, it would give off methane which warms the planet up 23 times as much as carbon dioxide. So, it is actually better for the planet to burn the wood rather than let it decay!

Where to Start

The best place to start is where there is most potential to save. According to EDF Energy, a typical UK household uses 3,300 kWh of electricity and 20,500 kWh of gas each year. In 2007, the energy used to heat, light and run homes across the UK accounts for 27% of all carbon emissions - around 40 million tonnes.

Use our CO2 calculator to see if changing you fuel can reduce your CO2 emissions.

  • Replace light bulbs with energy-saving equivalents. Compact fluorescent lamps last eight times longer than tungsten bulbs, and use a quarter of the energy. However, in 2008, it is still not possible to replace tungsten bulbs with compact fluorescent lamps in all applications. A tungsten bulb is by far the best choice for a room only occasionally used when an instant bright light is required.
  • Get the most out of your light - clean your light fittings for maximum reflection, and clean windows and skylights.
  • Set your heating thermostat to between 19° and 21°c. For every 1°C of overheating, energy consumption rises by 8-10% - it will also make you feel more comfortable. After all, who wants to live in a hot and stuffy home!
  • Make sure your water isn't too hot. Your cylinder thermostat shouldn't need to be set higher than 60°C (140°F) and if you use a dishwasher for all your washing the temperature can be reduced to 45°C.
  • If you're not filling up the washing machine or dishwasher, use the half-load or economy programme as most of the energy used by these appliances goes down the plug hole as hot water
  • If you have air conditioning, only use it on hot days where temperatures are 25°C and over, as natural ventilation should be sufficient. So, open windows and doors on hot days - Especially in cars!
  • Fit solar film onto windows to reduce the heat from direct sunlight. Avoiding air-conditioning could reduce your energy spend by 50%
  • Keep the gap between the switch-on temperatures for your heating and air­conditioning as wide as possible, so they will not both be working at the same time. For example, if your heating comes on when temperature dips below say 19°C, and your air-conditioning comes on at 25°C and above, when the temperature in your home is between 19°C and 25°C, you are not using energy on heating or air-conditioning and saving money.
  • You also need to think about your other energy users such as computers. Make sure that you remember to turn them off when you are not using them, especially at night, or install a simple timer to control the power.

If you are really serious about reducing your energy consumption consider reviewing every aspect of your home to see where savings might be made. Take a systematic approach. Start your review nearest the point of consumption and work back towards the point of supply. So if you take lighting look at the lamps and fittings and decide how to make them efficient first; then you can evaluate the potential benefits of measures such as lighting controls.

Once you have implemented changes it is important that you regularly monitor your energy consumption in order to maintain the efficiency you have worked to achieve. This could mean something as simple as checking the electricity meter every week and comparing the consumption over time. This is very important as most electricity and gas suppliers average out the cost over twelve months so the bill do not give any insight to saving made. Any significant changes in consumption should be investigated and dealt with." Wasted energy is the same as throwing money down the drain.

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