When EnergySage CEO Vikram Aggarwal looked at the results of his company'ssolar-homeowner survey conducted earlier this year, he was happy to see they validated his instincts.

In one question, the 4,000 homeowners who participated were asked where they got the idea to buy solar. Only 30 percent of them said they were influenced by an advertisement or solar company salesperson. The other 70 percent said they started their solar journey through an internet search, social media, news stories, personal recommendations or a community event.

Selling solar is becoming more about the consumer pull, not aggressive marketing, said Aggarwal, speaking with GTM at Solar Power International.

"Solar shoppers are no different than you and I," he said. "Do I want to be sold [to], or do I want to buy?"

Aggressive sales tactics are still a vital part of the industry, particularly for the largest national installers like SolarCity and Vivint Solar.

Vivint became a top installer nearly overnight in 2012 by recruiting a group of wildly effective door-to-door salespeople -- a key reason why SunEdison agreed to acquire the company earlier this year. Solar Universe is also a strong door-to-door seller.

SolarCity took the opposite approach. The company acquired Paramount Solar (aka "the closing machine") in 2013 in order to build up its remote sales capabilities, and has largely relied on a software-centric strategy to sell PV.

But performance has been slipping, said Aggarwal. According to SolarCity's earnings reports, the company pulled in nearly $200,000 for every sales and marketing employee in 2012. That number had fallen to $75,000 by 2014.

Customer acquisition costs are high across the industry. It costs the top U.S. residential installers around 49 cents per watt to close a deal -- two-thirds of what they pay for modules.

"The traditional sales model is to call or visit someone and tell them, 'You need to buy solar, and you need to buy it from me.' While that has been successful, the returns are diminishing," said Aggarwal.

EnergySage, a Massachusetts-based startup that touts itself as the Expedia.com of solar, has built an online service that allows solar customers to compare quotes from hundreds of installers. Since launching in 2013, the company has signed up hundreds of thousands of homeowners and converted 30 percent of quotes into sales. It estimates that there are up to 6 million people in the U.S. who are actively shopping for solar online.

Interestingly, EnergySage customers don't often pick the cheapest quotes. They choose the most responsive installer and look for the "right product at the right price," said Aggarwal. In other words, they shop around.

EnergySage has found that only 5 percent of customers with one quote end up buying solar. When they get five quotes or more, the conversion rate spikes to 40 percent. 

"The mass-market consumer is a shopper. They want choice and they want transparency," said Aggarwal. They often don't get either from solar installers.

Transparency is an issue for developers, too.

On the other end of the spectrum, Open Energy is trying to make financing commercial-scale PV projects easier through a new online service built to mimic applications for consumer debt.

Commercial solar projects suffer from a lack of standardization in lending, which makes closing deals expensive. This has hurt activity. In the second quarter of 2015, the sector saw a 33 percent drop in development, largely due to the cost of financing.

"One of the big problems we see is that it's all manual. We want to make it predictable, completely online and lower-cost," said Graham Smith, the CEO of Open Energy.

The New York-based startup debuted last June with an online peer-to-peer financing platform that allowed wealthy individuals to invest directly in projects. Its first fundraise brought in $720,000 dollars from 37 investors, offering a 7.5 percent annual return. It was followed shortly thereafter by another $750,000 project investment fundraise.

The company went quiet until this week at Solar Power International, where it launched a new web portal that allows developers to apply for financing, compare forecasts and terms, and close on a loan within 60 days.

The portal is brand-new, so the 60-day target is an estimate. Open Energy thinks it can eventually transform debt financing to a 30-day process -- a strong improvement over the typical three- to six-month process companies face today.

"We want to get money in the hands of the right borrowers as soon as possible. We put a lot of thought into making this as easy as possible," said Smith.

Of course, applying for a loan to support a commercial solar project is far more complicated than applying for a credit card or car loan. But the principles are the same: a polished interface, easy tools for comparing loan terms, and a place to store and revise documentation.

In an ideal scenario, a developer with all of its relevant documents in hand could complete the loan application process in 45 minutes, explained Open Energy CTO Alistair Potts. He said the company could send over an indicative set of terms by the end of the day.

Open Energy is looking to support commercial and industrial projects sized between 250 kilowatts and 5 megawatts, providing loans from $500,000 to $5 million. It currently has a partnership with one lender, GLI Finance, to buy up the approved loans. 

"We think people are going to get financing much more fluidly than before," said Potts.

In 2015, residential and commercial solar are less challenged by equipment costs, and more challenged by the cost to acquire customers and find money. The solutions to those problems may not be that complicated. In many cases, it's a matter of building the online shopping tools consumers and businesses are accustomed to using everywhere else.