Category Science

Solar power is especially useful for people in some remote areas of the world. Here, there may be no power stations and no network of gas or oil pipes to provide fuel for electricity.

This village in Angola, Africa, runs on solar power.

Solar energy is helping this village recover from the effects of war. Solar power provides street lighting and lighting for community buildings, such as the school and medical centre. It provides power for a freshwater pumping system and for hospital fridges that contain important medicines that need to be kept cool.

Computers can be powered by solar cells.

You probably use computers at school and at home. But in some parts of the world, there is no electrical supply to power computers. Solar-powered computers make it possible for more people there to use computers.

The Sun’s energy can cook a meal.

The Sun’s rays can be focused to create intense heat for cooking. A mirror or solar box cooker traps the Sun’s heat. The trapped heat cooks the food. Solar cookers mean that people do not have to collect and use up firewood for cooking.

Today we travel across the world in cars, boats and aeroplanes. Most of these vehicles use fuels, such as diesel and petrol. Burning these fuels releases harmful chemicals into the air. Solar power can keep us on the move and it causes less pollution.

Cars can fill up on sunshine.

Solar-powered cars don’t use petrol – they use sunshine. Hundreds of solar cells turn sunlight into electricity to power the car’s engine. There are even solar car races. In the American Solar Challenge, cars travel over 3,000 km across the USA, running on sunshine.

Sunlight could push spacecraft through space.

In the future, the Sun may be used to power spacecraft through space. A spacecraft would still need rockets to help it leave Earth. Once in space, sunlight would physically push on the sails to propel the craft forwards.

The Sun powers this plane.

This solar-powered aircraft is piloted by remote control. It can stay in the air for a long time to study weather patterns. The wings are covered with solar panels, providing the electricity for the aircraft’s motors. A battery provides power so the plane can fly during the night.

Roadside telephones, parking metres, flashing road signs and lights in bus shelters can all run on solar power. Houses, flats, offices and schools can all use solar energy to meet their energy needs.

Some schools are powered by the Sun.

Schools spend about three times more on energy than on books! Using solar power means there could be more money for books. The Star School in Arizona, USA, is completely powered by solar energy. It provides all the school’s power needs, keeps fridges cold and heats up lunches.

Continue reading “Our solar world”

The sun shines across our world every day. It will continue to do so for many millions of years. Mirrors, solar cells and specially designed buildings make it possible for us to use the Sun to supply some of our energy needs.

This solar power plant uses free energy from the Sun.

The Sun belongs to everyone, all over the world, so we can all use its energy. Although sunlight is free, solar cells are expensive to make and it is costly to set up a solar power system such as a solar power plant. However, when it is built, there is very little to go wrong with a solar power system – it just needs the Sun!

Solar power is a ‘green’ energy source.

It does not cause pollution by burning fuel and it does not make lots of noise. However, it is not perfect. To make a solar cell, rocks must be dug out of the ground and made ready to use. This uses up energy.

The Sun will last for millions of years. Other fuels will run out.

The most commonly used sources of fuel are coal, gas and oil. When we burn these fuels, they cause pollution. These fuels are also running out. When we have used them up, it will take millions of years for more coal, gas and oil to form under the ground. The Sun will continue to shine and provide power.

Scientists are looking for other ways to use solar energy safely and effectively. Could this experimental solar greenhouse tower produce enough warm air to rise up, drive a turbine and produce electricity?

In the future, solar cells may be sprayed onto road surfaces.

At the moment, solar cells are fitted onto hard panels. Advances in science may lead to solar cells that can be sprayed onto cars or road surfaces. Soft material could also be fitted with solar cells to cover any shape of house or building.

This solar-powered boat can study the oceans.

This boat floats on the surface during the day to recharge its solar cells. At night it can use the stored power to dive down deep to study the oceans. Lots of the Sun’s energy is trapped in the oceans. Scientists hope that one day a sea solar power plant could be used to create electricity.

The Sun shines on the Moon.

Scientists want to put solar collectors on the Moon and other planets to trap the Sun’s energy. The energy could be used to create electricity for humans on any planet.

Many people prefer to use energy sources that do not harm the natural world. These are often called alternative energy sources. Solar energy, wind energy and water energy are alternative energy sources.

These turbines use wind energy to create electricity.

Heat from the Sun warms the air around our planet. The warm air rises. As it does so, cool air sinks. The movement of air forms wind, which turns wind turbines. These turbines turn a generator, and this creates electricity. A group of wind turbines is called a wind farm.

Solar power can be used with other energy sources.

Sometimes, solar power systems have a ‘back-up’ energy supply for times when energy from the Sun is not enough. This may be other alternative energies, such as wind or water energy, or it may be a fossil fuel such as natural gas.

This machine is called a tokamak. It makes energy by copying the Sun.

The Sun makes its energy by joining, or fusing, atoms together in a process called fusion. For this to happen, the atoms have to be heated to 100 million degree Celsius. A machine called a tokamak has carried out fusion trials. A much larger version is being built in France by international teams and could provide a source of alternative energy.