Solar power is mindblowingly cheaper than just a few years ago. That's fantastic news for the Earth.

The sun.

Bringer of day. Giver of life. Causer of that squinty face you're making in your Christmas card photo.

And now, perhaps, also the unlikely savior of our climate and planet.

Thanks largely to a major decline in the cost of equipment, solar power has become the cheapest new energy source on the market.

"Unsubsidized solar is beginning to outcompete coal and natural gas on a larger scale, and notably, new solar projects in emerging markets are costing less to build than wind projects," Bloomberg's Tom Randall reports, summarizing a series of new data released by Bloomberg New Energy Finance, which surveyed 58 emerging economies in Africa, Asia, the Middle East, and South America.

The fact that this is taking place in the developing world is a big deal, as it could potentially allow some countries to skip dirty, costly fossil fuels altogether — or at least mostly.

Back in the '90s, much of Africa couldn't reliably talk to each other on the phone. Even in 2015, only 2% of African households had landline connections. But the advent of mobile phones allowed many countries to rapidly build communication infrastructure without having to install costly, resource-and-labor-intensive telephone lines. Today, nearly 90% of Nigerian and South African adults own mobile phones — about the same as the United States.

Similarly, falling costs could allow many of these countries to install cheap solar farms without having to first build big expensive coal and natural gas plants, giving them an edge over countries like the United States, which have to weigh the cost of building new, clean energy plants with the cost of tearing down old ones and deal with heavy resistance from the industries that operate them.

Of course, there are still some roadblocks to a full-on, balls-to-the-wall solar building bonanza.

Despite falling costs, installing solar panels across dozens of countries on multiple continents is time consuming.

Also, in areas that are less reliably sunny, fossil fuel sources can still be cheaper and more effective.

Nonetheless, it's an encouraging sign — and not just for those hoping to slow or reverse climate change.

"For populations still relying on expensive kerosene generators," Randall wrote, "or who have no electricity at all, and for those living in the dangerous smog of thickly populated cities, the shift to renewables and increasingly to solar can’t come soon enough."

When that day comes, we Earthlings could owe the sun big time.

At least until it swallows us all whole in a few billion years.