Hot Water for the Home from Solar Power

Creating your own home hot water by solar power is the easiest and most cost-effective way of using this free energy.

If you decide to heat your water in this way you may need to make some changes to the plumbing systems in your home. If this is the case, then be sure to get professional advice before making either structural or plumbing changes to your home.

There are several different ways to heat your water using solar power. You can even make your own solar water heater from commonly available materials if you have basic DIY skills. The water to be heated runs through a solar panel before it enters your home. This panel is usually mounted on a south facing wall or roof which is warmed by the sun. You will generally need a tank to store the heated water until you need to use it..

A flat plate collector is the most inexpensive and easiest collector. This is a thin rectangular box that has a see through cover, either glass or UV resistant plastic, which carries the water to be heated. Some systems intended for areas of the world that regularly experience freezing temperatures use an antifreeze solution rather than regular water. The water moves through the tubes, usually copper although plastic is sometimes used, to an absorber plate. This plate is painted a mat black to absorb the heat from the sun. As the sun shines on to the plate, it will get hot and heat the fluid that passes through the tubes. If you have a direct water-based system, the solar heated water passes into an insulated storage tank. For a system with anti-freeze the solution passes through a heat-exchanger to warm water.

Solar water heating systems can be divided into two major groups: Active and passive:

An active systems uses a pump to move the water between the solar collector and the hot-water storage tank. Active is the most common because it is the most efficient.

Passive systems rely on the fact that hot water rises to move the heated water from the collector to the storage tank. This may be slow and is not as efficient but it does not need electrical power to run the pump and is sometimes a more logical choice if you are trying to save energy.

Heating water using solar power is more affordable that generating electricity from PV cells and can be installed with DIY skills. Choosing to heat your water using solar power is a great first step towards home solar power.

Why use Solar Power?

All life on earth is ultimately powered by the light and heat from our sun. Without the sun, none of us would be here. The supply of solar power is limitless. It has been there for billions of years and will continue (we hope) for a few billion more. It causes no pollution and creates no greenhouse gases. I suppose the question should be “why on earth are we NOT all using solar power?” We have become spoiled by cheap energy based of fossil fuels such as coal and oil. These are no longer cheap and the carbon dioxide release when we burn them is slowly destroying our planet.

Solar power has many advantages over fossil fuel energy. The energy that the sun gives is is free - our only expense is that of collecting and storing the energy. These cost of recovery are falling quickly as new technology comes available and it's now possible to generate all of the power for your home from alternative energy sources, It has no emission gases to harm the earth's atmosphere.

There are a number of methods for recovering solar energy:

Focusing Solar Collectors: These have a rotating mirror (heliostat) which follow the sun around the sky during the day, These can provide a very high localized temperature which is then used to power a solar furnace. These solar furnaces can supply the energy for a boiler, turning cold water into steam. A conventional power generator is then used to generate electricity. Suitable for home use? Not really. These are better suited for centralized power generation in desert areas.

Flat Plate Hot Water Collectors: These allow almost every home to provide hot water via free solar power. They are inexpensive to install and have a relatively short payback time. They are usually composed of copper pipes which run through and enclosed panel with a black background. They are mounted on a south-facing roof and will provide hot water even on cloudy days. They do require some modification to the home's plumbing system so will probably only work if you own your own home!

Solar electricity Generators: These use photovoltaic cells which convert sunlight into electricity. Production of these cells has been doubling every two years, making this the world’s fastest-growing energy technology. The massive increase in manufacturing capacity has caused prices to fall dramatically making this an economic choice for both home and portable electricity generation.

I'm going to provide more information of using solar power to generate electricity and provide endless free hot-water in later posts.