Blackout C an you imagine what would happen if our energy supply failed If suddenly nothing worked If the television you were watching or the computer on which you were working went dead If the lights didn’t come on in the evening and the heating didn’t work If in a few days all the food in the refrigerator and freezer started to rot and there was no fuel to run the car You would be cold hungry and pretty unhappy This is not a plot for a science fiction movie A blackout is a real possibility if we run out of energy Most of our energy supply comes from burning fuels such as coal oil or natural gas These fuels are called fossil fuels because they formed in the ground millions of years ago Fossil fuels can be burned to give us heat They can also be used to generate power in the form of electricity 4 If we run out of power we may have to read and work by candlelight again
Most power plants like this one currently burn fossil fuels These fuels are nonrenewable and will one day run out The world demand for energy is increasing As the number of people in the world grows more energy will be needed to run our homes power our factories and drive our cars Relying on energy from fossil fuels has two main problems Burning fossil fuels releases carbon dioxide and other greenhouse gases into the environment These are contributing to global warming an increase in temperatures around the world Fossil fuels are also nonrenewable This means that once we have used them all there will be none left The world is using so much energy that our fossil fuels supply will probably be used up in less than 200 years We need to find other new sources of energy We need to find them quickly before our present supplies run out
Energy for Electricity E lectricity is a type of energy that we use to power many of our machines It is generated in power plants Most power plants burn the fossil fuels coal or oil The heat from burning the fuel is used to boil water The steam from the boiling water turns turbines which then turn generators The generators convert this movement into electricity Electricity is carried along transmission lines to homes schools offices and factories all over the country Steam Steam flow Turbine Generator Energy in fuel Furnace Condenser turns steam back into water Cool water flow This diagram shows how electricity is generated in a fossil fuel-burning power plant Fossil Fuel Problems When they are burned fossil fuels create air pollution All fossil fuels contain carbon When they are burned they give off the gas carbon dioxide CO2 Carbon dioxide is a greenhouse gas Scientists believe that greenhouse gases are making the world warmer and changing the weather all over the planet All fossil fuels are found underground and extracting them is often very destructive to the environment 6
Renewable Energy We need to make more use of forms of energy that are renewable Renewable energy can be used again and again and will never run out We can get renewable energy in many ways including from the Sun wind water living things and from underneath the ground At present only 18 percent of the world’s energy comes from renewable resources To save the planet this amount will have to increase in the future Electricity Cooling Tower cools condenser water Power flow Hot water HOT SPOT Tidal Power Tidal power is a form of renewable energy The tides move twice a day every day of the year This produces a large amount of energy that can be harnessed At present there is only one large tidal power plant It is at La Rance in France It has been in operation for more than 40 years and produces enough electricity to provide power for 20,000 homes
