We get the power to light and heat our homes from a surprising variety of sources. The concerns over how much longer we can keep generating power without thinking about the effects on the environment have been around for many years, but now firm evidence of global warming has made them all the more important.
Lets take a look at the different ways we produce energy.
We burn coal that is dug out of the ground. Coal is the remains of plants that lives millions of years ago. We have burned billions of tonnes of coal over the last 3 centuries and there is not much accessible coal left. It is also a bad thing to burn coal because it contributes to the greenhouse effect, making the whole planet hotter.
Natural gas exists in massive bubbles under the earth and can be extracted and burned. This is the gas we find coming out of kitchen hobs.
Oil is similar to coal in its origins and make-up. When refined into petroleum it runs our cars. However there is not much oil left either.
Solar Power comes in two major forms.
Solar cells generate electricity, while solar water heating systems use the power of the sun to warm up water for use at home. The simplest of these systems is to pump water through black-painted pipes on a roof facing the sun.
Windmills have been around for many hundreds of years. They have been used to drive pumps and grind corn, but recently have been turned into very effective electricity producers. Massive windmills are springing up all over the place, providing pwer when the wind blows. Offshore wind generators work the same as those on land, but are often more efficient because they are positioned near shores where there are regular predictable breezes.
Many great rivers have had dams built across them. This creates huge deep lakes behing the dam and lots of water pressure. Some of the water is allowed to flow through pipes pushing huge turbine blades around which in turn power generators producing electricity. Hydroelectric is clean and safe, but of no use in lowland flat regions where the rivers are small.
Another new development is wave power, where cleverly designed floating constructions turn the up and down motion of waves into electricity.
Some countries have lots of volcanos and hot lava or naturally hot water near the surface. This can be used to generate electricity and heat houses directly. Iceland is the country that has advanced geothermal technology the most.
Air Source, Ground Source and Water Source Heat pumps.
Underground the temperature is always pretty stable, so we can extract some of it and use it to help heat water.
Strictly speaking, batteries are not a power source, but are simply a way of storing the power we produce until we need it.