How to use solar power for electricity and water heating

The sun has been turning your house into a toaster oven this summer. So you keep wondering: Why can’t I use some of that solar energy to reduce my power bills? What will it cost; are there any new trends in the solar industry?

The main options available for your home are rooftop photovoltaic or ground-mounted systems that will supply your electricity and/or another rooftop device that will supply heated water.

Go solar for electricity

Solar electric panels are actually photovoltaic modules that turn sunlight into direct current, or DC, power. Inverters then convert the DC into AC, or alternating current, for use in your home.

You can install these panels on almost every style roof, including asphalt shingles and concrete tiles. A system usually needs about 80 square feet of panels for every kilowatt of DC capacity; usually systems have 400 to 800 square feet. A solar expert can calculate the size you will need. Some systems may have to be placed on more than one section of the roof to catch more sun. With proper maintenance, modern solar systems can last 25 to 35 years, and the modules also are usually covered by a 20-year warranty. So if something breaks, cost probably won’t be a big worry.

Many homeowners wonder whether a solar system will work when it’s cloudy or rainy outside — not something that happens too often in Arizona. Although you have a solar system on your roof, your home will still be connected to your local utility grid when you need it. Your TV or refrigerator or air-conditioner won’t shut down, because the interface between solar power and utility power is done very smoothly.

Solar electricity has become more affordable as prices have dropped over the past few years, according to the U.S. Department of Energy. New and more-efficient panels and inverters are developed all the time.

Each solar system is customized to your historical kilowatt-hour usage, not to the size of your home, according to Harmon Solar of Phoenix. Solar companies also take into account available roof space, the orientation of the roof and where panels will be placed.

Before a solar installation, you could have a 2,500-square-foot home with a monthly electric bill of $150 or $300, depending on how much electricity you use. As far as approximate total cost, a 5 kW solar system would be about $15,000; a 10 kW system about $30,000.

That 10 kW solar system on a south-facing roof may produce 18,000 kwh a year; but the same size system on an east-west roof may produce 15,000 kwh a year.

Government tax credits and utility incentives have contributed to making solar power affordable and providing Arizonans with an alternative for energy needs.

The new and popular industry trend of solar leases is also attractive to homeowners who don’t want to pay heavily up front for solar electric. You can have a zero-down lease or make an up-front down-payment on leases that last from 15 to 20 years. Leases can also lock in your energy rates for that time period, so you won’t experience huge rate increases from a utility company.

While monthly solar leases offer immediate savings on electricity with little or no money down, a prepaid lease or traditional purchase requires an up-front investment. The return on that investment will come over the years as you generate electricity to lower power bills.

Leases vary greatly, so shop smart. Watch for hidden escalation clauses. You also want to find out what the residual value of your equipment is once the contract ends. Typically, if you get a lease, you do not get federal and state tax credits. Lease companies get the credits.

One new catch is that utility companies are talking about charging homeowners with solar panels more for any electricity still used from the utility’s power grid. But probably, proposed increases will apply only to future solar users.

Prices of solar equipment may also increase over time due to inflation. Subsidies and tax credits could also be taken away. You have probably heard about the concept of net metering. This happens when the utility “buys” some of the homeowner’s surplus electric power; credits for the surplus are usually deducted from future power bills. There is a possibility that this could be cut back as well in future.

Go solar to heat water

According to the Arizona Solar Center, a statewide industry and utility trade group, solar energy can generally provide all normal domestic water-heating needs, with some backup for cloudy days. Your initial investment could be in the $5,000 range, although do-it-yourself systems are available. In the end, your out-of-pocket cost might be as low as $2,000 because of state and federal tax credits and grants from utilities. Industry experts say that most families can get their money back on a solar-water system in three to five years.

Just as with photovoltaic systems, solar water-heating maintenance costs are very low and the equipment has great warranties. If you already need to replace your current conventional water heater, a solar system could make sense.

Two types of water heaters are available: passive and active.

• In a passive system, a water container on the roof preheats the water before it enters a gas or electric heater, which is also your backup for cloudy days or heavier water use.
• In an active system, you have a roof-mounted collector with an 80-gallon solar water heater that uses a chemical process to do a heat exchange.

And solar water heating can be a great option for your swimming pool. You can have a roof-mounted heater or one on the ground in your backyard.

Source: azcentral.com

from Home Improvementer //
How to use solar power for electricity and water heating