Now that I told you what energy is, I will tell you why it is important to care about saving it and why people speak so much about renewable energy.
As you already know, energy is necessary to heat up (or cool down) your home, to run your parents’ car or the bus to go to school. You also need energy to switch on the bulbs in your bedroom, to cook your favourite meal, or to power your computer and TV. To do all these things, you need wood and withered leaves to burn in your fireplace. You need oil and natural gas to fuel your parents’ car, to fry your favourite fish and chips, to warm up your house, or to power the energy plant to produce the electricity for your bulbs. Waterfalls, uranium, and wind are also respectively used in hydroelectric plants, nuclear plants and windmills to produce the electricity for your grandma’s oven, for your PC, or for your hair dryer. These elements like wood, oil, water, wind, coal, necessary to produce energy, are called “energy sources”.
In our lives and in our society (especially in developed countries) energy is used more and more, and our daily activities depend too much on it. The question is: are there enough energy sources to produce the energy necessary for everybody? …Imagine what could happen if one day there were no more oil or coal to power our cars and trucks, to warm up our homes, to run factories, or to light our stoves. Or if one day there was no more electricity…
Energy sources can be divided in two groups: non-renewable and renewable ones.
Non-renewable energy sources are represented by fossil fuels (like oil, coal and gas) and uranium. Their main characteristic is that once we eventually run out of them, it will not be possible to make them any more in the short period. In fact, we are now rapidly using the fossil fuels that were formed millions of years ago from the remains of plants and dead animals that lived when the dinosaurs were still populating the Earth.
Most non-renewable energy sources are also potentially bad for people’s and environment health. For example, burning fossil fuels (like exhausts from vehicles, heating systems, factories or power plants) produces smog and gases that pollute the air we breathe and can make ill our lungs or our heart. In addition, the greenhouse gases released in the air when burning fuels may cause global warming (the increase of Earth’s atmosphere temperature) and acid rains (rains that contain harmful acid gases produced during fossil fuel combustion).
Renewable energy sources are represented by solar, wind, hydropower, biomass, geothermal, tides. Solar is used by photovoltaic and collector panels to produce respectively electricity for our appliances and heat to warm up tap water. Wind is used to turn windmills blade to produce electricity. Hydropower and tides uses the energy generated from water flowing to turn turbines and produce electricity. Biomasses (including wood, food and agriculture waste, straw and other organic materials) can be turned in fuels. Geothermal power uses the heat stored in the Earth to warm our houses and the water we use to wash up ourselves, our dishes, or our clothes.
The characteristic of technologies using renewable sources is that they extract energy at the same rate at which it is received from the sun rather than relying on energy stored during the course of millennia. Moreover, the majority of renewable energy sources don’t produce pollutants or greenhouse gases when transformed into electricity or heat to warm up our homes. For this reason, the energy produced by these sources is also called “green energy”.
On the other hand, the energy currently produced by renewable sources isn’t sufficient to meet our energy needs. Firstly because renewable energies rely on natural processes (like wind to turn windmills, sunshine to collect heat, tides to tap their energy and produce electricity) whose availability is pretty unpredictable. Secondly because with the current technologies we can only produce a small percentage of our energy demand and we still have to rely heavily on fossil fuels. Anyway, this doesn’t mean that we can’t play our part in reducing our energy needs or that it isn’t worth to use and keep developing renewable technologies.
Next time I will give you some tips on how to reduce our energy consumption. In the meanwhile, I would be really happy if you tell us the tips that you and your parents use to save energy in your homes!!!! See you soon!!