Myphuong Le was planning to buy solar panels for her Denver home until she crunched the numbers — and decided leasing the panels was a better deal.

“We debated owning or leasing,” Le said. “But when you consider that service and replacement are part of the lease, it looked like a better deal.”

So Wednesday, a crew from SolarCity was on the roof of Le’s Laredo Street home installing solar panels.

More and more Colorado homeowners looking for solar-energy systems are making the same decision.

In the first half of 2011, almost 54 percent of the 5,851 kilowatts of solar panels installed on homes in the state were leased, according to the Colorado Solar Industries Association.

In the first half of 2010, 60 percent of the installations were customer-owned, association data showed.

“Leasing has gone from zero at the start of 2010 to a dominant part of our market,” said Neal Lurie, director of the solar-industries group. “The reason: They simplify the process, and there is no upfront cost.”

A purchased system similar to the one installed on Le’s home would cost from $25,000 to $35,000, according to the Solar Industries Association.

A homeowner who buys solar panels is eligible for a rebate, a renewable-energy credit for the electricity generated and federal tax credits.

After incentives are applied, the costs of an installation comparable to Le’s would come down to $8,000 to $18,000.

However, leased systems do away with the need for upfront money.

Homeowners can get solar panels for zero down on a 12- year to 20-year lease and pay a set monthly fee. With a down payment, customers get more advantageous terms.

For example, with no money down, a SolarCity lease would cost between $25 and $100 a month — depending on the size of the system and the difficulty of the installation, according to SolarCity.

Opting for a $1,000 prepayment for one of the smaller systems would cut the monthly charge by about $10 to $15.

“Leasing is the great equalizer,” said Eric Wittenberg, regional director for SolarCity. “It makes solar available to everyone” — or at least every creditworthy homeowner.

Three California-based companies have become the biggest operators in the Colorado market — SolarCity, SunRun and Sungevity, Lurie said.

All three began offering leases in 2010. SolarCity now has 500 customers, Sungevity has 200 and SunRun has 1,000, according to the companies.

“Solar works best where it is sunny and not too hot,” said Bill Stewart, SunRun’s marketing vice president. “Colorado is ideal for solar. “The challenge has been the financing, and that’s what we bring.”

The solar-leasing companies sell the tax credits and accelerated depreciation allowed on the installations to investors to raise the money to finance the systems.

Once a system is installed, the leasing company gets a monthly payment from the homeowner and, in areas served by Xcel, a payment from the utility of 16 cents for each kilowatt-hour generated.

“It is a business model that has worked and is clearly attractive to consumers,” said Shayle Kann, a managing director at Greentech Media, a marketing and research firm focusing on clean-tech industries.

The electricity generated from the 5.6-kilowatt system on the Le home will cut the amount of power the family has to buy from Xcel Energy.

Le said that after working the numbers, she decided to make a prepayment of $6,700 — which made the monthly payment zero.

She estimates that the system will cut her average Xcel bill from about $115 a month to $35 a month.

Leases from SunRun and Sungevity are similar.

A big part of the savings comes from the fact that monthly lease payments are fixed, with an inflation adjustor, while Xcel rates are projected to rise faster than inflation.

Sungevity calculates that for a solar installation similar to Le’s, the payment averaged over 20 years would be about $63 a month and offers a $24,000 saving in electricity bills.

Sungevity employs an interactive, online system using satellite photos to develop a quote and gives the homeowner the ability to make changes — adding a prepayment, for example — to see how it affects the monthly payment.

“We are trying to break down the costs and remove the hassle factor,” said Sungevity’s president, Danny Kennedy.

Another selling point is that the leasing companies service the panels and guarantee a minimum amount of energy.

“If a panel isn’t operating at optimal efficiency, they will come swap it out,” said Gary Margolin, who has a lease with SunRun for his University Park home in Denver. “If there is a hailstorm, they take care of it.”

Margolin said he is paying $69 a month on a 12-year lease and that the system is supplying about 50 percent of the electricity used by his family of four in its 6,600-square-foot home.

“In the summer, we don’t use any electricity from Xcel,” Margolin said. “We can run the air conditioning at whatever temperature we can. We can do laundry in the middle of the day.”

The leasing companies got a boost in March when Xcel cut back its SolarRewards program — particularly the upfront rebates.

“That hurt customer-owned sales but did not affect the leasing companies because their incentives are built in over the life of the lease,” said Lurie of the Solar Industries Association.

Still, there are challenges the leasing companies will face, said Greentech Media’s Kann.

To raise the funds for solar installations, the industry relies on federal tax breaks that are up for renewal next year.

“Come 2012, that tax-equity financing is going to become a lot tighter,” Kann said.

That is going to squeeze the market and likely reinforce the position of the bigger companies.

“The companies that have good financing relationships — SunRun, SolarCity, Sungevity — are going to have an advantage,” Kann said.

Mark Jaffe: 303-954-1912 or mjaffe@denverpost.com