Solar water heaters have been around for a long time, in fact, it’s the oldest method of heating water known to man.
How do they work?
Solar water heaters are broken down into two different types;
- active, which make use of circulating pumps and have controls,
- passive, which is a lot like my leaf example above.
After the sun heats the water, the majority of water heaters will use tanks for storage, which are, of course, well insulated. When using a two-tank system, your conventional water heater, the one you have now probably, will be used to collect the pre-warmed water. Or you could have a one-tank system. This means that the back up heater and the tank are all using the same tank.
For residential use there are basically two types of passive solar collectors:
- Flat plate. Well-insulated boxes that contain dark absorber plates covered by either plastic or glass.
- Integral collector-storage. Sometimes referred to as ICS, these are black tubes held in an insulated box. Once heated, the water collected is funneled into the conventional water heater that serves as your back up water heater.
- Active systems may use direct circulation where the water is heated, held and delivered as mentioned above. These are great for climates where water is not expected to freeze.
Another system, uses an antifreeze component to be heated, then an exchanger is used to pass on the heat to the water. If you own a home up North, this would be the best system for you.
Be ready to ask questions from anyone that sells solar water heaters, such as:
- How much will I actually save with a solar water heater?
- Where would the solar heater be placed for maximum solar effectiveness?
- What size system do you recommend and why?
- How energy efficient is your system in comparison to others?
- How about the permits required, and the code enforcement board of my area?
You will find that the contractor you are working with is a good contractor if he can answer those questions easily and honestly. Ask for references and a copy of his license and/or certification.
Solar water heaters will of course require maintenance, but it’s important to realize that it depends on the components installed.
If, for example, you’ve selected a passive system, there will not be anywhere near the amount of maintenance required as does an active system.
Either system will require physical inspection its plumbing to detect small leaks. Electric components may require replacement parts after about 5-10 years in service.
The benefits garnered by the owner of a solar water heater will of course be energy costs saved, but they are substantial enough to warrant the investment in a solar water heater. Within the US, it is highly recommended that you access the following:
U.S. Department of Energy’s Consumer’s guide to renewable energy and energy efficiency.
Originally posted at DIY-Solar-Power.net.