It's been quite a month for SunRun, the San Francisco-based startup that's making it easier for people to get solar panels onto their rooftops.

Last week, SunRun unveiling a $100-million financing deal with PG&E Corp., the big northern California utility, which established a fund to enable 3,500 people to go solar. (See Solar's Strange Bedfellows.)

Today, SunRun is announcing a new round of venture capital funding led by Sequoia Capital and joined by existing investors Accel Partners and Foundation Capital. Altogether, the company said it had raised another $55 million, but it wouldn't say how much each fund had kicked in.

Taken together, the funding deal and venture investments represent a significant vote of confidence in SunRun's business model and its management team of CEO Ed Fenster and president Lynn Jurich, who met just three years ago in B-school at Stanford.

Here's why the model is appealing:

For homeowners, SunRun eliminates two major obstacles to rooftop solar. It provides financing, which can amount to well over $25,000, and manage the installation process, which can be daunting. SunRun owns the panels, in return for which homeowners agree to pay a fixed rate for electricity for 15-20 years. "That's very appealing to people," Ed told me last week. If the panels need servicing or replacement, SunRun takes charge again.

For suppliers and installation partners, SunRun provides a steady stream of customers and in return should get good pricing. The company currently works with about 15 installers.

For providers of project finance like PG&E Corp., which can borrow at low rates, SunRun is promising a steady return, based on the predicted stream of payments for electricity. Distributed energy over time also should ease congestion on the electricity grid.

The risk, for SunRun and its investors, is policy risk--the business depends on federal and state subsidies, which is why SunRun so far has focused on five states: Arizona, California, Colorado, Massachusetts and New Jersey, all of which have generous policys. There's also competitive risk--back in January, PG&E Corp. invested $61 million with Solar City, which competes with SunRun. Elon Musk of PayPay, Tesla and Space X fame is chairman of Solar City.

In today's announcement, Warren Hogarth, a partner at Sequoia Capital, is quoted as saying: "SunRun is the company creating and leading this opportunity for residential solar. Their unique model puts solar within reach of the average American home owner."

Well, yes, provided that the homeowner lives in a place where the sun shines (unlike my neighborhood, which is very shady) and in a state with a solar-friendly legislature and governor.

Still, this news is a nice boost for SunRun, for the rooftop solar industry and for decentralized power.