Uses


solar hot waterThere are only two basic types of solar water heaters: active and passive. The essential difference between them is the use of external power. Active solar heating systems employ tanks or heat pumps to circulate the but they gather, passive setups don’t. As their name defines them, integral passive solar water heaters work on the latter principle, and that lack of power dependency and resultant energy savings is one of the greatest selling points.

Passive solar heaters can be subdivided in to two classes: units in which the functions of heat collection and storage are separate—known as thermosiphon flat-plate systems—and arrangements that combine collection and storage into one integrated unit … namely, integral passive solar water heaters.

Solar water heaters use the sun’s rays to heat your water. They basically consist of solar collector panels and a storage tank.

The most common type has solar panels covered by a special toughened glass that sunlight can easily pass through. Solar radiation hits an absorber plate that has a number of vertical tubes or metal plates, depending on the system. The design and materials used for the absorber plate and tubes can vary; more sophisticated systems have a selective surface that absorbs a lot of radiation, while only emitting very little heat radiation.

A solar water heater can’t provide 100% of your hot-water needs year-round. Even in summer there may be several consecutive overcast days when the sun doesn’t provide enough radiation to sufficiently heat your water. That’s why all solar water systems have an electric or gas booster in their tanks, which kicks in when the sun drops out.

Solar power

We can also use solar energy to make electricity. The process is called photovoltaics (PV). If you have a solar-powered watch or calculator, you’re using photovoltaics!

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. And silicon from just one ton of sand, used in photovoltaic cells, 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.

As well as the fact that energy from the Sun is readily available, there are many other benefits. By locating solar panels on top of houses, no extra land space is needed and they can also be situated in urban areas, where there is plenty of available space.

In addition they are very easy to install, and although there are some high costs involved, they replace the need for other materials, such as tiles, to be used.

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