Bloomberg New Energy Finance just wrapped up its annual Future of Energy Summit in New York City. It is an overpacked, energetic conference that is largely preaching to the choir. 

Between the Paris climate agreement and ITC extension, the mood was decidedly upbeat -- but many participants also expressed painfully honest takes on the growing pains facing the clean energy industry.

Here are five of our favorite quotes that sum up the enthusiasm and honesty that conference participants shared this year.

“No matter which country you’re in, the cost of clean energy now is cheaper than the cost of climate change later,” said U.S. Secretary of State John Kerry. “Those betting on renewable energy will win big.”

At the same time, Kerry was critical of how little governments like the U.S. are putting into infrastructure, especially grid modernization, to allow for even greater penetration of clean energy. He called the lack of infrastructure investment “a tragedy -- actually, almost negligent beyond description.”

Kerry also cited BNEF’s statistic released earlier this year that investment in renewable energy overtook investment in fossil fuel in 2015. “That is a revolution,” he said.

“I’m not a car guy; I’m an electricity guy,” former NRG Energy CEO David Crane said, explaining why he owns four electric vehicles.

Unlike smart thermostats (“It’s still just a thermostat”), he argued that the EV will be the gateway for millions of people to begin to think differently about how they consume energy. 

The potential impact of EVs was also a highlight of the keynote by Michael Liebreich, chairman of the advisory board at Bloomberg New Energy Finance. By 2040, Liebreich said, BNEF is forecasting that electric vehicles are going to destroy 13 million barrels per day of global oil demand, about 15 percent of today’s oil demand.

Crane also reminded the room that his non-compete agreement with NRG ends next week. As for regrets about his tenure at NRG, Crane said, "One of the biggest mistakes I made was not reducing the size of the conventional side [of the business]."

“If you're signing a [power-purchase agreement] deal this year, you're losing money,” said Brian Janous, director of energy strategy at Microsoft.

Increasingly, the competitive cost of wind andsolarare cited as the reasons why countries and companies are turning to clean energy. These days, it’s good business, not just the right thing to do.

But at a panel discussion along with some of the largest tech companies in the world, including Google, Facebook and Microsoft, Janous was not alone in suggesting that companies like his aren’t always so sure the long-term bet on clean energy is absolutely cheaper than the mix of power coming from the local grid.

Others on the panel said that long-term PPAs may be cheaper over the lifetime of the agreement, but with low oil and gas prices, it's not guaranteed.

Even so, Microsoft’s CFO recently told Janous to keep pursuing clean energy, as enabling more clean energy is key to the company's corporate strategy. Others agreed on that point, too. The goal of supporting clean energy is about creating more demand that will push down prices and create market structures so that everyone, and not just individual mega-corporations, will benefit.

"To call the Western grid Balkanized is an insult to Macedonia,” said Jonathan Weisgall of Berkshire Hathaway Energy, talking about interconnection balancing authorities in the Western U.S.

Weisgall was not the only person talking about the challenges of changing generation mixes for system operators across the fractured U.S. wholesale markets.

The analogies used to describe Texas’ grid operator ERCOT were also not favorable, due in large part to the substantial amount of wind power on the system. “ERCOT is the Wild West,” said Randa Stephenson, VP of wholesale markets at the Lower Colorado River Authority. “The oscillation in ERCOT is unsustainable.”

She noted that the operating reserve demand curve instituted about 18 months ago has not functioned as the system operator had hoped it would and will be tweaked. “ERCOT pretty much just operates like a big swimming pool,” added Khalil Shalabi, VP of energy market operations for Austin Energy.

The largest grid in the U.S., while more stable than ERCOT, is also undergoing changes. PJM will transition to a full capacity performance auction for the 2017 auction to ensure greater reliability. “We’re going to have a much higher penalties for non-performance,” noted Stu Bresler, SVP of markets at PJM.

“Innovation isn’t about technology. It’s about your business model,” said Maryrose Sylvester, CEO of GE’s Current.

Industrial infrastructure and software are no long siloed, and not just for GE’s internal startup. Lisa Davis, managing board member of Siemens, also noted her company needs to move faster. These grid giants don't just need to integrate systems more effectively, but rather must rethink their entire business model and approach to serving customers. 

Utilities also need to reinvent how they serve customers. Liebreich said there are emerging technologies to support a grid business construct centered on a new service proposition for energy customers. “We sit and we wait for a miracle. No, a miracle is an opportunity and a miracle requires hard work," he concluded. "And it will be in the area of new services.”