Whether it is in the home or in the school, when we talk about energy we are mostly talking about heating, lighting and electrical appliances. 

• Fossil Fuels and Climate Change 

The energy produced when we burn fossil fuels such as coal, natural gas and oil comes from carbon and hydrogen. When we burn these fossil fuels we release carbon (in the form of CO₂) drawn from the atmosphere by plants millions of years ago. Fossil fuels such as coal, natural gas and oil are composed almost entirely of hydrogen and carbon. When we burn fossil fuels we produce energy and release the carbon they contain. 

Black coal is almost entirely carbon; a ton of coal when burned produces 3.7 tonnes of CO₂. Oil is less carbon rich than coal containing two hydrogen atoms for every atom of carbon, and so produces less CO₂ and more heat when burned. Natural gas (Methane) is the least carbon-rich of the fossil fuels containing just one atom of carbon for every hydrogen atoms. 

• Types of Renewable Energy 

Wind Energy

Since ancient times, people have been harnessing energy from the wind. As long as 5,000 years ago, the ancient Egyptians were using wind to sail ships on the Nile River. Later, people then built windmills to grind grain and pump water.  Some of these windmills still exist. Holland is famous for them. 

Like the old fashioned windmills, today's wind turbines use blades to collect the wind's kinetic energy. Wind flows over the blades, causing them to turn.

The blades are connected to a drive shift that turns an electric generator to produce electricity. 

Solar Energy

The Sun is amazing. Without it, none of us would exist, and there would be no life on Earth.

Without sunlight, plants could not make food, so there would be nothing for us to eat. Not only could plants not make food without the Sun, they also couldn't make oxygen, and no animals could breathe.  The Sun produces nearly all the heat on the planet, makes the wind blow and the ocean currents flow and controls the weather too. 

People have been using solar energy for years. We can use the Sun's energy for a number of different things. First, to heat things--our houses, the water in our houses, the food in a solar cooker, and so on. This is called solar thermal energy. The second is to turn the Sun's light directly into electricity, using solar panels. This is called photovoltaics. 

Hydropower

Hydropower is power that comes from the force or energy of moving water, which can be harnessed for useful purposes. Before the widespread availability of electricity, hydropower was used for irrigation and to operate machinery including watermills and textile machines. There are many different types of hydropower including tidal power and wave power. 

Biomass Energy

Biomass is the oldest form of energy. For thousands of years people have burned wood to use for heat and for cooking. In fact, wood was the biggest energy provider in the world until the mid- 1800's. 

Biomass is any organic matter that can be used as an energy source. Organic means anything that is alive or was once alive a short time ago. Organic materials are renewable energy sources like trees, plants and animal waste. 

Geothermal Energy

Geothermal energy is heat that is generated 4,000 miles deep inside the Earth's core. The centre of the Earth is called the iron core. The Earth is made up of several layers including the crust, mantle, outer core and iron core.

Geothermal energy was first used by people centuries ago. 

There are many hot springs around the world that are heated by the Earth's core and ancient people used these for bathing. Geothermal energy is also a renewable energy source. The Earth continually produces rain for water and magma for producing heat. Deep inside the Earth, the water and rock absorb the heat from the magma and we can dig wells and pump out the heated water or steam. This heated water can be used for heating and generating electricity.

Advantages of Renewable Energy 

• Carbon dioxide emissions from burning fossil fuels are a significant contributor to global warming and climate change. Renewable energy, compared to fossil fuels, has either no associated carbon dioxide emissions or at worst is carbon dioxide neutral.
• Renewable energy sources such as water, solar power and wind, are infinite and will not run out, unlike fossil fuels such as coal and gas which are not renewable.
• By diversifying the type of energy sources nations use, energy supply will become more secure and countries will become increasingly self-sufficient, which in turn will reduce CO2 emissions generated by the import/export industry.  

What You Can Do

Small changes can make a big difference. We can reduce our energy-related CO₂ emissions through energy saving measures both at school and at home.

• Turn off lights and appliances (fully!) when they are not needed.
• Use energy efficient light bulbs and appliances; over its lifetime just one CFL bulb can reduce your lighting costs by up to €60 and avoid 400kg of CO₂ emissions.
• Turning down the thermostat by even 1°C can reduce your heating bill by up to 10% and results in massive CO₂ savings.
• Buying renewable energy from your supplier may also be an option available to you. Purchasing electricity generated from renewable energy sources reduces CO₂ emissions and provides funds for further investment in renewable energy generation.

Each of these small steps will help you reduce your CO₂ emissions, and also save money. Other methods of saving energy may require a greater initial investment, but should save money over the long term. These include the use of solar panels, geothermal heating, double glazing, improved insulation, and wood-chip boilers.

Calculate your energy-related CO₂ emissions

Use a carbon calculator to estimate your school's energy-related carbon emissions. You can download one from the Irish Eco-Schools website http://www.greenschoolsireland.org/ or check for other calculators that can be used in your country.

The number of kWh of electricity consumed can be worked out by looking at past bills. Similarly, the quantity of gas or oil consumed can be worked out by looking at bills. What kind of changes can be seen in energy consumption during different months of the year? Why?

If you have a record of the electricity and heating usage prior to joining the Eco-Schools Programme you can compare present and past usage levels to determine the CO₂ savings you have made through implementation of the Energy theme!

If some or all of your electricity comes from a renewable energy source, such as hydro, wind or solar power, then this is exempt from your calculation.

Source: HSBC Eco-Schools Climate Initiative Teachers' Manual