“Solar” is the Latin word for “sun” – and it’s a powerful source of energy. In fact, the sunlight that shines on the Earth in just one hour could meet world energy demand for an entire year!
People have used the sun as a heat source for thousands of years. Families in ancient Greece built their homes to get the most sunlight during the cold winter months. In the 1830s, explorer John Herschel used a solar collector to cook food during an adventure in Africa. In 1954, scientists at Bell Telephone discovered that silicon (an element found in sand) created an electric charge when it was exposed to lots of sunlight. Just a few years later, silicon chips were used to help power space satellites.
Today, more than 10,000 American families get all of their electricity from solar power. The panels are made of silicon and silcon is made from just one ton of sand. When used in photovoltaic cells, silicon could produce as much electricity as burning 500,000 tons of coal.
You might be wondering why we don’t use solar electricity all the time. Solar power systems make a different kind of electricity than big power plants do, so different wiring is needed – and that can be expensive. There are a few big solar power plants in the United States, mostly in California. It’s difficult and expensive to make a lot of electricity using photovoltaics – the panels cost a lot, and a lot of open land is needed. We can use solar power in two different ways: as a heat source, and as an energy source. Here’s a simple break down of the 3 most common ways we use solar energy.
Solar Cells - Also known as photoelectric cells convert light directly into electricity. In a sunny climate, you can get enough power to run a 100W light bulb from just one square meter of solar panel energy This was originally developed in order to provide electricity for satellites, but these days many of us own calculators powered by solar cells.
Solar Water Heating -Heat from the Sun is used to heat water in glass panels on your roof.This means you don't need to use so much gas or electricity to heat your water at home. Water is pumped through pipes in the panel.This helps out your central heating system, and cuts down on your gas and electric bills. However, in the UK you must remember to drain the water out to stop the panels freezing in the winter.Solar heating is worthwhile in places like California and Australia, where you get lots of sunshine.
Solar Furnaces – Furnaces use a huge array of mirrors to concentrate the Sun's energy into a small space and produce very high temperatures.There's one located at Odeillo, in France, used for scientific experiments. It can achieve temperatures up to 3,300 through 3,800 degrees Celsius. In California, theSolar One power station uses the Sun's heat to make steam, and drive a generator to make electricity. The station looks a little like the Odellio solar furnace , except that the mirrors are arranged in circles around the "power tower". As the Sun moves across the sky, the mirrors turn to keep the rays focussed on the tower, where oil is heated to 3,000 degress Celsius, The heat from the oil is used to generate steam, which then drives a turbine, which in turn drives a generator capable of providing 10MW (Mega Watts) of electrical power. Solar One was very expensive to build, but as fossil fuels run out and become more expensive, solar power stations may become a better option.
This was just a brief history on what solar energy is being used for and what’s come out of it since it’s deveolpment.
As always Keep it Green
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