Arizona should rightly be called "The Sunshine State" instead of Florida. We receive more hours of sunshine than any of the other 49 states, especially in southern Arizona. One consolation is that we have laid claim to the motto "The Solar Energy State".
There are two major uses of solar energy in Arizona. One is for solar pool and spa heating and the other is for solar domestic hot water. Heating water is one of the simplest and most efficient uses of solar energy.
Solar domestic water systems heat the hot water for your home. These systems can be either active or passive. An active system generally consists of a collector, control, pump, storage tank and some form of freeze protection. A passive system is usually either a thermosyphon system or an integrated collector storage system (ICS) , commonly called a batch heater. The storage tank is in the panel itself. These systems do not have any moving parts.
There are many advantages of the passive ICS systems over the more common active systems. The estimated life of some systems is 30 years plus. They are trouble-free and very efficient. These systems save you money, particularly if you have an electric hot water heater, by significantly reducing your monthly utility bill.
Solar pool and spa heating is probably the most efficient use of solar energy because of the relatively low temperatures needed to make a pool or spa comfortable (usually 85 degrees and
100 degrees respectively).
Generally, a pool solar system is sized at 80% - 100% of the surface area of the pool. Therefore, an average pool would be sized at 450 NET SQUARE FEET. Net square feet is emphasized because this is one of the two critical things you have to know before you even consider buying a system. You must know the net square feet and the amount of heat the systems collect measured in BTU's per square feet per day. Fortunately, these figures are readily available for all reputable major manufacturers from two independent testing laboratories. The two labs are the Florida Solar Energy Center (FSEC) and the Solar Rating Certification Corporation (SRCC). Generally, these figures will range from 800 to 1,000 BTU's/sq.ft./day. DO NOT consider buying a solar pool system until you are shown an official certification sheet from one of these two testing centers. The sheets will show both the NET square feet of the model and the BTU rating.
An ideal situation is when you have a combination pool and spa. The solar system will be considerably oversized for the spa that will allow you to heat the spa to temperatures most of the winter.
If you heat your pool or spa with natural gas, a solar heater will usually pay for itself in a few years.
The State of Arizona has reinstated the state solar tax credit effective January 1, 1995. A tax credit of 25% of the cost of solar energy devices is available for new residential solar energy installations in Arizona. The credit is not to exceed $1,000 per residence, and may be carried forward for up to five years.
