First of all, let me make it clear that this article is about "utility-scale" solar power, not rooftop solar power. Rooftop solar is a different beast, because it's more expensive per unit of electricity than utility-scale solar but it generally competes with retail electricity prices rather than wholesale electricity prices. For millions of Americans, and many more worldwide, rooftop solar is already cheaper than electricity from the grid, but until recently, utility-scale solar projects weren't cheaper than other types of power plants (ignoring externalities, which we shouldn't really do but we do). That has been changing.
As you can see in the chart at the top, the levelized cost of electricity from solar power is expected to be as low as $60/MWh, lower than the lows for any fossil fuels or nuclear power. And that assumes a 20-year lifespan for the solar power plant, much less than (maybe not even 50% of) the actual lifespan of a solar power plant.
But we don't have to wait a few years to find solar power beating fossil fuel projects on price. Earlier this year, Recurrent Energy won a contract to sell power to Austin Energy in Texas for 5 cents/kWh under a 25-year power purchase agreement (PPA). More recently, Austin has designated solar a "default energy source." If you look at that chart above again, you can see that no fossil fuels come in below $6 cents/kWh.
More recently, the average bid from utility-scale solar power plants vying for contracts in Georgia (the US state) came in at just 6.5 cents/kWh. The average! 56 companies bid to sell power from their solar farms. No details were given on the minimum bid, only the average, but even 6.5 cents per kWh is cheap!
In a recent power auction in India, the cheapest solar bid came in at 8.6 cents per kWh, which is apparently cheaper than what it would cost to make coal imported from Australia viable.
Most recently but perhaps most impressively, a recent power auction in Brazil with a specific tranche dedicated to solar had one project bid in at 5.65 cents/kWh... with no subsidies included at all. The average across the auction was 8.9 cents per kWh, and despite aiming to provide contracts for 500 MW worth of solar power projects, 1,048 MW worth of them got contracts. Reportedly, even 8.9 cents per kWh is lower than what fossil fuels can offer in Brazil.
Lastly, solar has been more competitive than fossil fuels in Chile, which has excellent solar irradiation, for awhile now. Fossil fuels can't touch solar in Chile.
The tide is turning. With solar costs falling and fossil fuel costs rising, I have a feeling it is going to turn very fast.