During our excursion to the Museum of science, we learnt various uses of the energy which reach the Earth from the Sun. These energies are known as Solar or wind energies and are renewable energies that are also used for our greenhouse operation. Electricity can be generated from both Solar as well as Wind Energy. WWS (wind, water and solar) is being considered as the source to replace of coal and oil in near future. We all desire to live sustainable, healthy lives and yet electricity produced from these means is expected to be less costly. For this purpose, we first will need to evaluate the amount and geographical distribution of these resources.
The heat from the Sun is harnessed by humans using a variety of technologies. Energy in the form of electromagnetic radiation emitted from the Sun that falls on Earth every hour is even more than the energy consumed by humans in a year and is known as “Solar Energy”. Such energy is then converted into usable thermal or electricity energy by man. Current commercial solar cells can convert about 20% of the sun’s energy into electricity, so one cell meter square can generate up 200 watts under ideal conditions. That’s enough electricity to run a MP3 player or an electric pencil sharpener but wouldn’t be enough to use a microwave or a hair dryer. Photovoltaic converts solar energy directly into electricity; On the other hand, lenses and mirrors help turn water into steam which can drive turbines in order to provide electricity.
We acknowledged the fact that wind energy is actually converted form of solar energy. There are many issues relating to a wind turbine impact on the surrounding environment, and these contribute to the significant level of disadvantages of wind turbines. These include impact on wildlife and noise pollution. But, these have much smaller impact as compared to fossil fuels. For example, approximately 40,000 birds are killed by wind turbines every year, which is 50 times less than birds killed by oil spills. Careful selection of location can minimize these impacts.
