Solar Power: Bring Me Sunshineby Dharmendra Kapri | 17-07-2016 03:38 |
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We live on a solar-powered planet the ultimate source of energy on this planet is the sun the feel of the heat of the sun on your skin is solar energy! It provides energy for plants to grow, which in turn provide food (which is energy) for animals. The sun provides us with heat and light every day, which we can use to make electricity: There are three types of solar power: PVs You?ll have seen solar powered calculators, watches and garden patio lights? The same technology can be used to provide electricity to whole buildings - just on a larger scale. This type of solar power comes from photovoltaic cells or PVs. Lots of PVs together make up solar panels on the roofs of houses and other buildings. They work by using the sunlight to split electrons from atoms. The energy released during this process is converted into electricity. In Kenya there are more homes with PV systems than there are connected to the National Grid! Thermal Collectors These create hot water rather than electricity. They are made up of a series of tubes sandwiched between sheets of glass (with a black backing to absorb the sun?s heat) on the roofs of houses. Water in the tubes heats up in the sunlight and starts to flow into a hot water tank. Bingo - the house has hot water! Systems like this can reduce the need for other energy sources by two thirds. Passive Solar Energy This is when a building is designed and built to make the most of the natural position of the sun. So in the Northern Hemisphere (e.g. UK, USA, China) houses can be built facing south (where the sun shines most of the day) with big windows on that side to act like a greenhouse and warm the house without having to put the heating (or lights) on as much. This can halve heating bills! On a big scale, solar technologies are used to power whole settlements, space craft and satellites. Here are some examples: * The largest Solar PV ?farm? in the world is about to be completed near Moura in Portugal. Each of the 2520 solar panels is the size of a house! It is expected to provide power for 30,000 homes. * Satellites and the Hubble Space Telescope are covered in solar PV cells which power the computers, cameras and radio systems on board. Up in space there are no clouds or seasons to interfere with the sunshine!
* The robots sent to Mars have solar cells too. ?Spirit? and ?Opportunity? trundle along using solar power so they can take amazing photographs and send them back to Earth. The two robots were only meant to last for a 90 day mission – they have now been up there more than 5 years! * The World?s largest solar cooker is in Rajasthan, India. It can produce food for 10,000 people! So solar power appears to be absolutely brilliant! Here?s why: * The sun isn?t going to run out – well not for another 5000 million years! So it is a sustainable form of energy (provided the materials required to make the equipment don?t run out). * No harmful gases are released once the equipment is installed * It works well in remote areas where there isn?t easy access to the National Grid. * It works well in poorer, hot countries as it costs very little to run. A small PV cell can power a whole house. * It works in cold and cloudy conditions too. Solar power has been used in both the Arctic and Antarctic.
But there are down sides to solar power: * It is expensive to install – the materials are costly. * Storage and transportation of the electricity to where it is needed is difficult. * In many countries there is too much ?dark time?, especially in winter, when most power would be needed for lighting and heating. * Large scale solar farms take up land which could be used for growing crops for food, and they are considered ugly by some people. |
