The cleantech industry is filled with references to internet businesses.

There's the Amazon.com of energy efficiency, a comparison often made for any company with an online marketplace; there's the Salesforce of solar, a comparison also made for companies improving business efficiency; and then there's even the Pets.com of solar, an analogy used by New York Times columnist Paul Krugman for Solyndra after the company went bankrupt.

So forgive us if you have internet-comparison fatigue. But here's another one that we just can't resist. 

The Massachusetts-based web company EnergySage says it is going to be the Expedia.com of solar.

Or heck, even the Travelocity.com, Kayak.com or LendingTree.com of solar. Take your pick.

But don't take it from us: "The EnergySage Solar Marketplace will do for the solar industry what sites like Kayak, Travelocity and Expedia have done for the travel industry," explained the company in a press release this week.

EnergySage has just rolled out a new product that mimics what those businesses have done so well: make shopping easier, faster, and cheaper by allowing customers to compare prices.

EnergySage has been developing its capabilities for some time -- starting out with a simple site assessment tool and a one-dimensional portal that helped consumers look at different clean energy options. In the summer of 2012, the company received a $500,000 investment from the Department of Energy to build a more interactive site that would help consumers compare quotes from installers. On Wednesday, EnergySage finally released its Marketplace platform.

Greentech Media got a tour of the site before it rolled out on Wednesday. It's a very clean interface that combines new capabilities in web-based site assessment with the business model perfected by quote-comparison sites. The marketplace's functionality and usability is light years ahead of other similar sites like FindSolar.com or Solar-estimate.org. If the site compares to any existing site, it's probably Sungevity's iQuote platform. But EnergySage offers a completely different set of functionalities that allow customers to compare and rate numerous companies. 

Here's a screenshot of what a customer might see after looking for quotes:

The functionality on the installer side is equally simple and seemingly easy to use.

"I don’t think we’ve seen anybody building a platform like ours that gives you quotes like this," said Vikram Aggarwal, CEO and founder of EnergySage, in an interview. "We compete with lead-generation companies, but those groups don't address the need to make an informed decision in real time."

The Department of Energy estimates that non-hardware costs -- administrative needs, permitting, and financing -- account for up to half of the installed cost of a solar system. In order to make transactions simpler and less expensive, the agency has deployed millions of dollars to boost companies like EnergySage.

Product development is the easy part, however. The real challenge will be customer outreach. EnergySage will be competing directly with big companies like SunPower, SolarCity, and Sunrun that have a large marketing presence and quote delivery services. The company will also face competition from large regional players with strong built-in sales channels. Recognizing the need to find an early customer pipeline, EnergySage has partnered with the Massachusetts Sierra Club to help with early outreach in that state. It will also work with other nonprofits on similar outreach programs.

EnergySage has a slick platform. But it now needs to prove that its service can offer high-value sales leads to companies that they can't get anywhere else. (After all, the company makes money by charging installation companies for each transaction). And it needs to prove to consumers that they can trust the installers and quotes, along with getting a smooth experience.

Which is why calling yourself the Expedia.com of solar is such a really good marketing tool. It's a trustworthy model that people know works.