Solar Hot Water Heaters
What, Why, How and Which?

Solar hot water heaters provide economical benefits to the homeowner and can reduce dramatically the household carbon dioxide footprint.

Cost and Tax Credits

Investing in a solar thermal hot water heater is a modest investment in the $2,000 to $4,000 range that can pay itself back in 2-3 years by saving on heating bills. Not only that, at least 30% can be paid back by energy tax credits. California, realizing the potential, has recently embarked on a rebate program to encourage investments in residential solar water heating systems.

View the history of solar hot water heaters

What is a solar powered hot water heater?

The most prominent component is the sun itself, radiating free of charge light rays toward planet Earth. In fact, the energy reaching Earth in one day is sufficient for Earth population energy demand over one year.

The second component is the solar thermal collector (also known as the solar hot water panel), a relatively small aperture frame absorbing the sun radiation. More on collectors' types and solar heaters' types in solar water heaters types

The third component is a relatively small insulated reservoir of water, pros tend to call it the hot water storage tank .

The fourth part is the fluid that moves the heat from the collector to the tank.

• The fluid can be the water itself in those areas where freezing is a rarity.
• In areas where freezing is a threat, a non toxic anti-freeze fluid corrosion inhibitor fluid is used in the loop of pipes that goes between the collector and the tank. This is very much the same concept one finds in his car if he lives in areas where the winter is c-o-l-d.

An optional component is the pump. If no pump is used, the solar hot water heater is called a passive solar water heater

Well, you guessed correctly, if a pump is used, than the system is called active solar water heater.

The initial cost of passive heater and the life cycle cost are cheaper than the cost of the active heater. In these days, people are conscious about money and about clean air. They want to save money and to reduce the carbon foot print their family generates.

The pump, unless it gets its energy from a small photovoltaic panel, uses electricity or is using other burning fuel. The energy the pump is taking for its operation can amount to 10% of what the solar heater saves.

Another component, is a backup heater using usually gas or electricity, for heavy cloudy days. In most systems an electrical back up water heater is embedded inside the solar water tank.

Solar water heaters is one way to use solar energy for home applications

The other way and a more expensive one is to directly convert sun radiation into electrical power

Why use solar radiation to heat water?

There are two reasons to use solar thermal hot water systems:

• The first motivation to convert your heating water system into a solar system is economical. The sun works for you free of charge, and the initial cost is covered partly by tax credits and by subsidized loans. The balance will be covered by saving on energy bills over a few years. After that, you practically enjoy free of charge hot water supply
• The second reason is that clean air and reducing global warming are becoming more and more important. Heating water not by a solar system, send 4.5 tones of greenhouse gas (carbon dioxide) into the air annually. This is comparable to what one average family car on the roads put out annually. There is something we all and you can do about it.

The Solar Water Heating System practical alternatives

What practical options do you have?

Your second option is to bring in a professional contractor that will assess what might be the optimum solar hot water heater for your site, will bring in the system's components and install it on a turn key basis. This is a bit more expensive and you loose the excitement of DIY (if you like this excitement). The time it might take from when you decide to heat water by harnessing the sun until you can enjoy hot water heated by the sun is very short if you choose to go that way. A few days to a few weeks, for most regions.

Which of the solar hot water heaters fits your needs?

It depends on where you live (Sun Belt States or more northern states)
It also depends on installation constraints such as the position of the collector in regard to the tank. In passive solar hot water heater the tank must be installed higher than the collector.
If you add a pump the collector can be installed in a higher altitude relative to the solar hot water tank

In sizing the system you need to consider 10 years ahead (the heater life expectancy), to accommodate for family growth...

If you're not able to install your solar hot water heater right away, there are still ways you can cut your hot water energy use. Green Energy Efficient Homes provides hot water efficiency tips for electric hot water tanks that can be helpful for any type of water heater you use