Contrary to popular belief, solar hot water heating is not at all a new technology. Solar water heating systems have been used commercially for over a century now, with the first commercial water heater (the Climax Solar-Water Heater) going on sale in 1891 in the United States. By the year 1900, over 1600 houses in California were equipped with this solar water heater.

Due to its effectiveness and low cost, the solar water heating gained popularity until, by 1941, more than half the population of Florida was getting its hot water through solar water heaters!

Solar hot water heating only lost its popularity due to lowered electricity rates, along with an aggressive campaign by Florida Power and Light, to increase electrical consumption. This was done by offering electric water heaters at bargain prices. Thus Florida's solar water heating was brought to halt.

The United States is not the only country with a solar water heating history. There are many other countries where solar water heating was used in the past and has since fallen out of use - but not all of them. In fact, there are currently more than ten million Japanese households which heat their water using solar heating systems. This is definite proof that it is a workable technology.

Important Facts about Solar Hot Water Heating Systems

* Solar water heating can be used in any climate. Sound unbelievable? Check it out on the U.S. Department of Energy website. They say so as well.

* The fuel used to run a solar water heater is sunshine. And, at the time of this writing, sunshine is still free - no tax has been added yet.

* A solar water heater can reduce your water heating bill by 50%-80%. But with energy prices going up, the amount of savings will soon be even higher.

* Aside from reducing your energy bill right now, a solar water heating system will protect you from future energy price increases. Your heating will no longer rely on fossil fuels for electricity.

* When building a new home, or when refinancing, the economic aspect of this becomes even more interesting.

You can, for instance, include the cost of a solar water heater with a new thirty-year mortgage package. This would usually amount to about $13.00 -$20.00 a month. Federal income tax deductions for mortgage interest would reduce the payment for the solar water heater by about $3.00 -$5.00 per month.

If your fuel savings with a solar water heating system is $15.00 or more per month (which it likely will be) you will have reduced your monthly heating bill right then and there.

* Solar water heating will significantly reduce your carbon footprint, and reduce the demand for fossil fuels which pollute the environment.

* Solar heaters can be installed in combination with backup systems. In fact, you could install a solar water heater next to your existing system and make it possible switch to conventional water heating whenever necessary. This way you are guaranteed to always have hot water.

-Types of Solar Hot Water Heating Systems

There are two types of solar water heating systems, active solar water heating systems and passive solar water heating systems. They both work on the same principles.

The only difference is that active systems have a pump or other mechanical means of moving the water through the solar heating systems, and passive systems rely on nature's principles: warm water rises to the top, and cold water sinks to the bottom. Therefore, with a passive solar water heating system, the water storage tank must always be positioned above the solar water heater collector.

- Active Solar Hot Water Heating

There are two main designs of active water heating systems. Which one is best for you depends on the type of climate you live in.

There is what's called an "indirect circulation system" which uses a non-freezing heat-transfer fluid to transfer heat from the collector to a heat exchanger (a device used to transfer heat from the heat transfer fluid to the water in your storage tank). This is good for colder climates.

There is also the direct circulation system, where water is simply passed through solar heat collector and then routed to the water storage tank for use. This system works fine in milder climates.

- Passive Solar Hot Water Heating

Passive solar water heating systems are usually cheaper than "active solar water heating systems," as they do not need controls or pumps to circulate the water.

But generally, they are not as effective as the active systems. If you live in a warm climate, a passive water heating system might be all you need. Passive water heating systems are also known for being very reliable.

Essentially, solar hot water heating systems consist of a water storage tank and its solar collectors. The solar collectors are used to collect solar energy which heats water, and the tanks store the heated water. That's all there is to it.