It’s summer, and as energy costs rise along with temperatures, we’re all looking for ways to cool our homes more efficiently. Hawaii has the highest electricity rates in the U.S., but renewable solar power is a great solution right now, with state and federal incentives that pay back 65 percent of the up-front cost. Choosing the system that’s right for you can be tricky business, so the answers require a little preliminary research. “There’s no one-size-fits-all,” says John Ogrodny, general manager of Photon Works, an installer and manufacturer of photovoltaic (PV) systems.  

Before signing a photovoltaic (PV) contract, ask the following questions to find the right system for you.

Net-Zero- Energy Home: A home that produces as much energy as it consumes

1. How much energy does my house use?

“We look at the homeowner’s electric bill to establish the baseline kilowatt-hours (kwh) they consume per month,” says PV contractor Mark Kelley, owner of Lighthouse Solar Hawaii. Once your contractor knows how much energy you use, he or she can determine how many panels you’ll need to become a net-zero-energy homeowner.

Photo: Laura Poirier of Sunetric

2. What condition is my roof in?

PV systems add weight to your roof, so it’s important to make sure yours will hold up. Consult your PV contractor to make sure your roof is PV-ready. It’s also important to note that installing a PV system will require your contractor to penetrate your existing roof. (He or she will apply flashing to re-seal the new seams created).

If you don’t want to puncture expensive ceramic tiles, or if you don’t want to add extra weight to your roof, consider a PV canopy or carport such as those available at Skylights of Hawaii, which produces electricity for your home without disturbing your roof.

3. How large should my panels be?

Photo: Courtesy of RevoluSun

It depends on where you live and how your home is oriented. The panel efficiency each roof requires (which is also linked to size and cost) differs according to how much sunlight your home attracts.
Orientation affects the amount of sunlight your panels will pull in naturally. South-facing roofs, for instance, draw in more sunlight than roofs facing other directions, according to Alex Tiller of Sunetric. Homes that are likely to pull in a large amount of sunlight require less solar-pulling power. Therefore, you can go with a less-expensive, larger panel.

However, if you live in a less-sunny area, you’ll likely need more efficient panels with better solar-pulling power. Those usually come in a smaller size.

“Eighteen percent efficiency is a good kind of module if you live where there are  mountains, but in Ewa or Nanakuli you can go with a less-expensive, 12-to-15-percent panel because you get so much sun,” says Larry Ponce of Solar Services Hawaii.

Note: Small roofs may need smaller, more efficient panels no matter how sunny it gets. That’s because less space for panels equals less opportunity to collect sun-light. That means you’ll need the highest sun-harnessing potential possible in the smallest amount of space.

Your solar contractor will be able to determine which panel is the most efficient size for your roof.

To see how much sun your area gets, visit hawaii.gov/dbedt/info/energy/publications/solardata/.

4. What should I look for in a solar contractor? 

In addition to generous warranties, licensing, experience and good reputation are key. Installers should hold a C-61 license for solar hot-water systems and C-13 Electrical Contractor’s license for PV. 
Ask how many solar systems a company has sold or installed. To find out if there have been complaints filed, and how they were resolved, visit the Hawaii Department of Commerce & Consumer Affairs at hawaii.gov/dcca or the Regulated Industries Complaints Office at hawaii.gov/dcca/rico. And always check references!

5. Are warranties available? 

PV systems are warrantied between 20 and 25 years, depending on the brand.
Note that the installation work is separate: The state requires a minimum one-year warranty for labor, but some companies give between five and 10 years. Solar hot-water panels usually carry 10-year warranties or more, “because they take more abuse, with the water circulating through them,” says Rolf Christ of
R & R Solar Supply.

6. How can I pay for solar? 

First, there are plenty of government incentives. For instance, Hawaii Energy now pays a $750 instant rebate for solar water heaters. For both PV and solar water heating, Hawaii homeowners receive a 30 percent federal tax credit and a 35 percent state tax credit; all incentives are carried over from year to year until exhausted.

All the local companies we listed in this story will help their customers find financing, some providing it through packages of their own, such as Hawaii Energy Connection’s popular KumuKit. RevoluSun and Sunetric partner with a third party, SunRun, which pays for the PV and charges you a low monthly fee for the energy your system generates (essentially, it’s a rental program for the PV panels installed on your roof, which translates into savings for you, but eliminates the commitment to buy).

Many local banks and credit unions offer attractive loan packages for solar home energy. First Hawaiian Bank’s (FHB) Energy Smart Program includes a five-year, zero-interest personal loan for solar water heating. “The interest saved is roughly another $1,000,” says Derek Wong, vice president of credit products. For PV systems, FHB offers a home-equity line of credit at zero interest for 18 months, afterwards rising to variable rates, or a locked-in rate available through participating solar contractors.

7. Can I “sell” solar energy I don’t use? 

Yes! Choose Net Energy Metering (NEM), which gives you credit for excess energy that you give back to the electric grid. You’ll also be able to draw on electricity provided by the grid during cloudy weather. Choose a contractor who will help you obtain your NEM agreement with Hawaiian Electric Company, which must be signed by an installer with an electric license. Another option is Hawaiian Electric’s Feed-In Tariff (FIT) program, which is ideal for the largest residential systems and small businesses, as it allows you to sell larger amounts of energy back to the public utility. Visit heco.com to find out which program is right for you.

8. Do I need a backup energy source?

NEM can provide cost-effective backup for PV. You can also invest in a  battery that stores extra electricity on site for use when the power goes out.

For a backup to solar hot-water systems, it’s worth considering on-demand, also known as tankless, gas water heating. “A more efficient back-up heat source than electric, gas can save energy at a rate of up to 35 percent compared to other energy systems,” says Greg Toth, vice president of marketing for The Gas Company.
       

9. How many years will it take to get a return on my investment for PV?

Because PV systems vary in size and efficiency (and so do the homes they produce energy for), estimates range from five to  15 years. Your solar contractor can give you a more targeted estimate based on your unique needs and the system you choose, Tiller says.

Learn More

Curious about what it would be like to live with PV? Attend a Solar Open House (separate programs are offered by Sunetric and RevoluSun) where you can talk story with homeowners who’ve installed PV. RevoluSun and Sunetric also offer Solar Seminars, where homeowners can meet the experts, ask questions about the installation process, learn about financing options and more.

Efficiency First

“Before installing PV, the rule of thumb should be to get most of the energy inefficiencies out of a home,” says Chris DeBone, managing partner of Hawaii Energy Connection. Why? “You don’t want to oversize the PV system,” says Rolf Christ of R & R Solar Supply. In other words, “picking the low-hanging fruit of conservation before adding PV is a smart move,” says Tristan Roberts of buildinggreen.com, a leading national  authority on environmentally sound construction. Here are some steps to take before purchasing your panels:

1. Perform an energy audit. Many photovoltaic contractors will perform this service prior to installation. “We do an energy audit with homeowners, suggesting that old appliances be swapped out for ENERGY STAR® models and incandescents for efficient lights and more,” says Larry Ponce, owner of Solar Services Hawaii.

2. Swap light fixtures. LEDs are 90 percent more efficient, says Rick Lau, general manager of Hawaii Home Expo.

3. Explore the possibilities. Passive features like deep eaves, awnings and window treatments also conserve energy, as do good habits: turning off lights, air conditioners and electronics when not in use. If you have central air, a solar attic fan, which draws hot air out, “is a good fit because your house is well-sealed, but not so much if you have an older, single-walled house designed for the tradewinds.” says James Wells, project manager for Energy Pro Hawaii. Darren Furumoto, operations manager of Alternate Energy Inc., recommends high-quality insulation, which helps keep hot air out and cool air in.

4. Install a solar water heater. Furumoto and other experts advise installing solar (thermal) hot-water panels, which can reduce your energy use — and the size of your PV system —  by 25 to 35 percent. “Once clients start seeing those savings, they’re ready to install PV,” says Kalani Kam, marketing director of Hawaiian Island Solar.

5. Leave room for retrofits. If you’re considering a great deal on PV that may only be available for a limited time, but can’t afford to make other energy retrofits before installing, there is a solution. “We’ll put a PV system in for you now, and size it down, factoring in the energy that you’re going to save by making your home more efficient down the road,” says Gregg Murphy, sales manager at RevoluSun.