Sources of energy
We use energy all the time and need it just to stay alive which is why we need to eat. But in order to help us stay more comfortable we need to use energy to heat and light our homes and schools, and for everything we make and use.
Luckily, energy can be stored to be used when it is needed. For example; plants store the suns’ energy for use to live overnight and if deciduous throughout the winter. They also release energy for use by other organisms either directly to the animals that eat them or indirectly by burning them to provide heat.
There are different sources of energy that can be used, but they are either renewable (can be replenished at a rate that does not deplete the resource) and non-renewable (from a source that cannot easily be replenished).
Some renewable energy sources can provide heat and electricity, these include:
· solar energy, which comes from the Sun
· geothermal energy, which comes from inside the Earth
· biofuels which comes from plant and animal matter
Whilst others produce only electricity. These include:
· wind energy using wind turbines
· hydropower using the power of gravity and its effect on water
· ocean energy using either the power of the tides, ocean currents or waves
Most of our energy however comes from non-renewable energy sources which are often referred to as fossil fuels (coal, oil and gas). These are biofuels that were laid down over millennia as plants died and decayed and became compressed under newly formed sediment which turned into rock. Nuclear energy also uses a non-renewable resource (Uranium and Plutonium) to generate electricity.
Trends in energy use
Energy use continues to rise in the UK and globally. We need more and more of it to continue to provide for our current lifestyles. At home, whilst our buildings have become better able to hold the heat we provide we have also increased the temperature we heat them to and we continue to increase the amount of electrical equipment we use. How many separate electrical devises do you have in your kitchen or bedroom.
Energy use in schools also continues to rise and for much the same reasons. How much electrical equipment has been installed in your school? How much of this has been in the last 12-24 months?
There are many impacts of using energy from fossil fuels
Environmental and social issues
Burning fossil fuels to provide heat and electricity, results in the release of gaseous and particulate compounds which include:
|
Pollutants produced |
Source producing pollutant |
Environmental impacts |
Human health impacts |
|
Carbon Dioxide
(CO2) |
· Natural Gas
· Coal
· Oil
· Petrol & Diesel |
· Global Climate Change (also called Global Warming)
· Ocean acidification |
· None identified at the concentrations that occur from energy use |
|
Nitrogen Oxides
(NOx) |
· Natural Gas
· Coal
· Oil
· Petrol & Diesel |
· Global Climate Change
· Acid Rain
· Oxygen depletion from rivers / lakes
· Ozone smog (which interferes with photosynthesis and plant growth)
· Regional haze which reduces visibility |
· Causes or aggravates respiratory problems such as asthma, emphysema and bronchitis
· Aggravates existing heart disease
· Damage to lung tissue
· Premature death |
|
Methane
(CH4) |
· Natural Gas (through poor combustion and leaks)
· Oil
· (Farm animals and landfill sites) |
· Global Climate Change (21 times more potent than Carbon Dioxide)
· Ozone smog (which interferes with photosynthesis and plant growth) |
· Causes or aggravate respiratory problems such as asthma, emphysema and bronchitis
· Aggravates existing heart disease
· Damage to lung tissue
· Premature death |
|
Sulphur Dioxide
(SO2) |
· Coal
· Oil
|
· Acid Rain
· Regional Haze
|
· Could cause or aggravate respiratory problems such as asthma, emphysema and bronchitis
· Can increase the negative affects of ozone |
|
Mercury compounds |
· Coal
· Oil
|
A persistent pollutant passed up the food chain and toxic at threshold levels and reduces reproductive capability |
Affects human health including the: nerves, kidneys, heart and circulatory system and immune system. |
Whilst most of the emissions associated with our energy use have number of environmental and health risks, it is the release of Carbon Dioxide (CO2) that is the main focus of the UK Government’s activity. This is because CO2 emissions has the biggest influence of all the Climate Changing gases emitted in the UK, and there are legally binding reduction targets of 12.5% based on 1990 levels which the UK has to meet between 2008 and 2012 under the Kyoto Protocol.
In addition to the health issues identified above there is also the wider social issue of inequality of use and availability both geographically and temporally
· Geographically - some parts of the world particularly the developing world have limited access to energy
· Temporally - we are consuming non-renewable energy resources to make our lives today easier but this has long term problems of potential reduced availability and the legacy of the environmental problems we are creating for future generations
Economic issues
All the above environmental, health and social issues have a knock on effect on the economy, which is only likely to increase as time goes by. In addition, there is security of supply issues as the UK transfers from an energy exporter to an energy importer. We will increasing become dependant on other countries for our energy supplies which adds greater uncertainty on energy prices and reliable of supplies in the future.
Increasing the diversity of our supply (as many different energy sources from as many different suppliers as possible) and the use of renewable energy resources will help reduce the UK exposure to this threat.
Reducing energy use
Reducing energy use will help to reduce the negative environmental, social and economic impacts associated with energy use and help to improve the security of supply.
It is generally possible to reduce energy use in all schools in the UK without reducing the quality of service (e.g. heating, lighting or ICT) gained from the use of energy. In many cases using energy more efficiently will improve comfort and productivity in school.
Good Housekeeping and maintenance
The Carbon Trust has produced a number of free guides to help you manage your energy use more effectively and we would recommend you obtain copies of these.
Ten things you can do now at no or little cost to reduce your energy use are:
1. Heating – check operating times and adjust them to better reflect actual need
2. Heating – check temperature set points and adjust to appropriate levels
3. Heating – keep windows shut when the heating is on and certainly shut them at the end of each day
4. Lighting – switch off lights at the end of every lesson and at the end of the day, so that a positive decision to switch on lights is made at the start of each lesson
5. Lighting – appoint pupil monitors to inspect communal areas such as toilets and cloakrooms and switch off lights if they are not needed
6. ICT – switch off monitors and PCs at the end of the day and only switch them back on again as they are required
7. ICT – enable standby and power down facilities on all equipment, particularly shared equipment such as printers and copiers
8. Electrical equipment – inspect the school to determine what electrical equipment can be switched off overnight. Examples include any drinking provision (hot and chilled water), ICT equipment, vending machines with non perishable goods and lights. Label them with green stickers to help staff identify equipment that can be switched off
9. Monitoring – keep track of monthly meter readings and present this in graphical format to make it easier to identify changes in use that may indicate wasteful practices. Why not use our monitoring tools which is available from your homepage?
10. Install 7 day timers (available from on equipment that continues to be left on unnecessarily
About renewable energy
Schools can offer excellent opportunities for renewable energy technologies, but to make their impact stretch as far as possible you should reduce energy use as much as possible first. Additional ideas to help you do this are available from the Carbon Trust. Although there are a number of renewable energy technologies the main ones that offer the most potential for reducing Carbon Dioxide emissions are biomass and wind energy.
Biomass is the term used to define wood fuels and can usually be installed into schools with existing boiler houses if there is sufficient space to store the wood fuel (which is bulkier than fossil fuels) and there is a ready supply of the fuel within a short distance to the site. However, the economics usually mean it is only really an option for schools not connected to the gas network. Further information on Biomass can be found here
Wind energy is most likely to be available to rural or sub-urban schools with large enough grounds to allow installation to be far enough from schools and other buildings that the noise of the turbines and the air turbulence affects of the buildings are minimise. Further information on Wind energy can be found here
In addition to these technologies there are solar electric and solar heat options which are easily installed in schools and can contribute to providing some of the schools energy needs.
Solar Electric (also known as Solar Cells or Photovoltaic cells) converts sunlight into electricity using a semi-conductor material (usually silicon). Solar cells are currently very expensive and installing enough to provide all a schools electrical needs is currently prohibitive. However, the technology is improving rapidly and prices are falling fast as a result of increased production capacities. Further information on Solar Electric can be found here
Solar Heat (also known as Solar Thermal) is used to collect some heat from sun and daylight and deliver it into the schools hot water supply. Further information can be found here
