As solar-lease style agreements gain traction among homeowners as a way to install solar with little to no upfront costs, the companies offering the options are struggling to keep up with demand.

Partnerships with banks and other financial institutions have helped finance the solar leases in the past.

But companies like SunRun are now starting to look beyond such arrangements and into securitizing the assets and selling them to allow access to more capital at lower costs to meet the demand.

At least eight companies are offering such arrangements to homeowners in various states across the nation, and they’ve been successful in signing up a lot of people.

SunRun CEO Edward Fenster recently told CNN Money that the company is spending $40 million a month to keep up with demand. That means the $200 million tax equity financial partnership SunRun announced with U.S. Bancorp in early May will essentially be committed within about a five-month period, or by October of this year.

With more than 10,000 homeowners signed up so far under, SunRun has a strong base of liquid assets that could be converted to securities and then sold as bonds, according to company spokesperson Susan Wise.

“During securitization, you essentially pool those assets so they can be bought and sold in the form of bonds,” she said. “Activities are underway to make this happen. But it is in the very early stages.”

It’s an attractive idea for companies like SunRun.

“These capital markets provide access to much deeper and more stable long-term financing sources than tax equity,” Wise said. “That’s not to say we will leave tax equity all together; it’s just adding more to the portfolio. It reduces the cost of borrowing. We can scale faster and at lower cost to make solar affordable to more Americans.”

Bundling became a dirty word when the housing market fell in 2008. But many other industries use bundling to finance their growth. These include auto loans and music rights, among others.

The SunRun leases should make good securities since homeowners are inclined to pay their leases.

“They’ll be more apt to pay it because they’re saving money on their electric bill,” Wise said. “It’s important to note that there’s no definite timeframe. It’s still an ‘if.’ But we expect it to happen with the next year.”

Other companies, like Sungevity and SolarCity, have been expanding their presence in the residential solar leasing market and may also consider selling solar securities.

Pictured: Tom's installation in Sandwich, Mass., courtesy of SunRun.