If you follow the money that’s still flowing into solar, you’ll find innovative business models being valued above innovative technology. Now it’s up to a few companies to educate Wall Street that there is more to the category than a shiny panel collecting dust in a desert.

Last week Credit Suisse invested $400 million in Sunrun and SolarCity, which essentially refinance homeowner electricity bills, putting SolarCity in a better position to IPO in the third quarter of this year.

“The clear implication is that large, sophisticated institutions have decided that these are good risk-adjusted investments. In other words, SolarCity and Sunrun business models makes sense,” says Abe Yokell, partner at RockPort Capital Partners.

While there are three distinct parts to SolarCity’s business, its SolarLease and SolarPPA (power purchase agreement) have been the driving force of its growth. All eyes will be on the company and Goldman Sachs, hired to underwrite its initial public offering, to see if it can explain the often complicated math. It’s similar to GE Capital’s consumer finance model, which made previously expensive upfront investments affordable by breaking the purchase into monthly payments. In this case, the equipment is solar, the investment is in electricity, and the bet is against rising utility energy prices. Homeowners pay nothing to go solar and lower their monthly electricity bill.

Morgan Stanley, U.S. Bancorp, and Google are among the leading investors that finance these rooftop solar installations, which are managed and maintained by SolarCity, Sunrun, Clean Power Finance, the three category leaders.

Just because residential solar projects are getting big name investors, it doesn’t guarantee an easier road to a public offering. Wall Street, having been burned by stocks like First Solar, needs to understand that falling panel prices have only benefitted residential solar projects, making it cheaper to invest in equipment. Panel prices have dropped 80% from more than $4.00 per watt to $.80 per watt in less than four years. The education will ideally happen within the banks.

“Often times when investment bankers want a piece of big business (like an IPO), they will run the relationship up the flag pole and introduce the folks in the project finance group to the company,” says Yokell.

SolarCity will also need to closely monitor how Goldman positions the company considering it led BrightSource Energy’s botched IPO. The solar thermal power plant builder withdrew its initial public offering in April, citing tough market conditions. Sources say there were many reasons why BrightSource cancelled its plans, but it demonstrates that Wall Street is still struggling to embrace and understand solar.