Soaring electricity costs were a make-or-break issue for Corina Ishi­kawa, who runs a day care for children at her air-conditioned house in Ewa Beach.

Her average monthly electricity bill of $500 and up — it reached $600 last September — was enough to make her consider closing down Xcel Child Care.

She tried turning on fans and opening windows, but some of the kids in her care are sensitive to vog. So the air conditioning was switched back on.

Then she discovered the option of leasing a solar photovoltaic system.

SolarCity, a California company with an office in Mili­lani, installed the 8.88-kilowatt system — 37 panels in all — atop her two-story house at no cost, with no down payment required, just a high credit score.

Ishikawa said she and her husband couldn’t afford the upfront costs of the system after putting in an addition, but the goal was to lower her electricity bill.

It’s worked.

With the solar PV system, she pays about $14 a month to Hawaiian Electric Co. and $194 a month to SolarCity under a 20-year lease.

The Ishikawas are part of a growing trend in Hawaii and across the nation, according to Gabriel Chong, president of the Hawaii Solar Energy Association.

He estimates between 20 percent to 25 percent of homeowners in the state are now opting to lease instead of buy solar PV systems. Solar companies are adapting to the demand by offering more leasing options.

Purchasing a solar PV system averages about $32,500, depending on size (and before a 65 percent federal and state tax credit), according to the U.S. Solar Market Insight report. Typically, the systems pay for themselves in five to six years.

For homeowners who can’t afford a system upfront, most solar companies in Hawaii offer the option of a lease or power-purchase agreement.

Leasing is similar to leasing a car. You pay a monthly fee over a set period. For PV systems, 20 years is common. Depending on how it’s structured, the monthly fees may stay flat over the life of the lease or increase incrementally.

The company installs, monitors, maintains and repairs the system over the lease period.

A power-purchase agreement is similar. The customer agrees to have the system installed and signs a long-term contract to purchase the power generated while the solar company takes care of installation and maintenance.

The companies are considered "service providers," and because they own the systems, they reap the benefits of the tax credits.

So what if a customer wants to sell the house?

Solar PV system leases can be transferred to new owners or paid off and included in the resale value of the home. Or, for a fee, some companies will move the system to the new house.

Solar PV systems are sprouting up around Ishi­kawa’s Ewa Beach neighborhood, by all appearances. Ewa Beach houses, because of a sunny location, require fewer panels to produce the same amount of energy.

It’s important to evaluate all your choices, read the fine print and decide what’s best for your home, whether it’s a lease, power-purchase agreement or outright purchase of a solar PV system.

When all is said and done, remember that besides lowering electric bills, solar is helping Hawaii move toward clean energy.

For details, check online at solarcity.com/hawaii or call 792-1233.