With what? Microsoft needs 24/7 reliable power, and solar and wind can't provide that. Gas and oil can, but they want to get away from that.
With batteries you can get solar to provide reliable power 24/7, but the price ends up much higher. That's not the price that's often quoted as being cost competitive with other power sources. However, that's not the end of the story because you don't just need 24/7 power, you need it 365 days/year, and there's this thing called winter. Storing the power you get during the day to be used at night (or potentially the power from yesterday to be used today because it's cloudy) might be feasible with batteries, but storing the power you get during the summer to be used in the winter just isn't. The only solution there is just to build out massive over capacity so that you produce enough power
in the winter to meet your needs, but that's another huge rise in cost.
I'm a big fan of solar, but people who claim its
in general competitive with coal now wrong. It's competitive on some marginal uses and as a supplement to other more stable sources of power, but the price needs to keep dropping significantly before it will replace coal/oil/natural gas/nuclear.
I do expect that the price
will continue to fall, both as the price of batteries falls and as the price/watt of solar panels falls. One issue to be concerned with is that the price of the panels is starting to fall below the
other costs of producing solar power (the price of the land, the infrastructure on the land like roads etc. to construct the site and connect it to the grid, the running/maintainence costs, etc.). Once those other costs overwhelm the costs of the panels, further price declines in the panels themselves matter much less for the other all price/watt to the consumer. However given the lower costs of the panels there are ways to optimize these sites for those other costs which should give room for further price drops. They were being built and designed in ways that made the most out of each (expensive) panel, but now that those are becoming cheap you can optimize for the cost of building, or the efficient use of space, or lower maintenance, rather than just getting the most out of each panel. There are significant gains possible there, so I do expect a bright future for solar power and investment in the technology now brings that future closer. But its certainly not the case that we should be rejecting other sources of power because we think that solar is just the obvious choice
now. It's not.
There's also an issue of build time. It might be much faster to build more solar power than a new nuclear plant, but no one is talking about building a new nuclear plant, there's talking about using one that already exists. Given permitting requirements it will take
years before a new solar facility is online and producing power, and in the meantime the new demand from Microsoft's data centers will mean higher energy prices for everyone; something that Thermal seems to be opposed to.