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A rough year for the solar industry is showing no signs of turning around as we head into earnings season. Rather than being excited to hear what solar companies are about to report, investors are worried about how bad the industry has gotten in the last quarter.

China's first-half solar boom has ground to a halt and the U.S. is expecting to go from a boom year in 2016 to a very down year in 2017. All of this has been terrible for solar stocks, but there are signs the clouds will break... eventually. 

The IEA gets bullish on solar energy

The International Energy Agency doesn't have a terribly good track record of predicting how quickly the renewable energy market will grow, but it's starting to see a lot more opportunity in the space. A recently released report called the Medium-Term Renewable Market Report said renewable energy installations hit 153 GW last year, including 49 GW of solar. 

The better news long term is that the IEA increased its projection of renewable installations between 2015 and 2021 by 13%, to 825 GW. Cost reductions in wind and solar energy are leading to renewables being cost-competitive around the world, from emerging markets to developed countries like the U.S. 

Not all 825 GW of new renewable energy will be solar, but the fact that renewable energy demand is growing and estimates are increasing is very good for solar investors. 

Solar+sports strikes again

The solar industry made its debut in the sports landscape in 2014 when Yingli Green Energy's logo was splashed all over the FIFA World Cup. Since then, the 49ers, Redskins, and Jets are just a few of the pro sports teams that have decided to go solar. 

The Utah Jazz took it to the next level by partnering with Vivint Solar (VSLR) to install 2,700 solar panels on their stadium and rename it the Vivint Smart Home Arena. What's curious about this deal is that it's coming when Vivint Solar is having its own financial difficulties, and it's in a market where there's very little solar installed. 

Financial details of the naming-rights deal weren't announced, but NBA teams make about $4 billion per year on naming rights, so it's safe to say the deal is worth millions annually, even in a small NBA market. You have to wonder if that's a good investment for Vivint Solar, especially when you consider that Yingli Green Energy's sponsorship, which was seen around the world, didn't help the company avoid a financial collapse that has it close to bankruptcy. 

Earnings season begins next week

Wednesday, Nov. 2 kicks off the solar earnings season when First Solar (FSLR 1.33%) gives a peek into its finances. Investors should be looking at usual metrics like revenue, margins, and net income, but bookings will really come into focus this quarter. 

We know that demand in the second half of 2016 is going to be down, and 2017 looks like it'll be light on demand as well, but are there bookings in 2018 and beyond? First Solar releases its bookings and backlog each quarter, so we'll get an idea where the project velocity is right now. If First Solar is winning projects, it will be a good sign for the industry, but if the company is seeing dark days ahead, it could be a long year for solar investors.