The global solar market has been downgraded for 2017. A worrying sign? Hardly.

Even with a 4-gigawatt downward adjustment in projected installations, it's still going to be a record-breaking year for new solar capacity additions -- yet again.

The 81 gigawatts expected this year are more than double the amount of solar capacity installed in 2014. And it's 32 times more solar deployed a decade ago. (In the year 2000, global installations totaled 150 megawatts.)

Those numbers come from GTM Research's latest edition of the Global Solar Demand Monitor, which closely tracks market-moving and market-dooming developments in countries around the world.

One of the most telling statistics: By 2022, global capacity will likely reach 871 gigawatts. That's about 43 gigawatts more than expected cumulative wind installs by that date. And it's more than double today's nuclear capacity.

In fact, by the end of 2017, solar PV could rival global nuclear capacity. That's a major milestone.

According to the Nuclear Energy Institute, there are 391.5 gigawatts of nuclear plants operating around the world. When the year closes out, there will be roughly 390 gigawatts of solar PV plants spread across the globe, according to estimates from GTM Research. (The final numbers could be larger, since the outlook for China is growing stronger.)

For the first time ever, solar power plants and nuclear power plants will be on equal footing -- at least when it comes to raw capacity.

Of course, capacity only tells us part of the story. It's all about electrons. And in that regard, nuclear still dominates.

Nuclear generates 2,476,671 gigawatt-hours of electricity every year, accounting for roughly 11 percent of global generation.

Solar, on the other hand, only accounts for 375,000 gigawatt-hours of electricity yearly, or about 1.8 percent of global generation.

The generation gap is significant. But a crossover is approaching.

In 2014, the International Energy Agency looked at PV growth rates through the middle of the century. Under a high-growth scenario -- which basically mirrors the current real-world scenario -- IEA found that the world could get 16 percent of its electricity from PV by 2050, and another 11 percent from concentrating solar power. That would make solar the dominant energy source globally.

In the last three years, growth rates and cost reductions for solar have far exceeded projections. Meanwhile, high costs, slow construction and competitive renewable alternatives are causing the global nuclear industry to falter.

The trend lines are becoming clearer every year.