They will also want reliable power, which seems like justification enough to keep their options open. A “phased, modular approach” sounds like it would give them options. Maybe Microsoft could install solar and/or batteries later and use their natural gas turbines for backup?
With enough batteries they might get through the night, but seasonal shortages are much harder to handle that way.
I bet a carbon tax on data centers would be popular if the Democrats get back in.
You can generally solve seasonal shortfalls cheaply by simply adding more solar / wind until you no longer have a seasonal shortfall just a massive surplus in a different part of the year.
Put another way if you want to store power say 1GWh for the worst month, well a solar panel provides a lot of power over even the worst month. 20MW of solar panel averaging even 40MWh/day * 30 days = 1.2GWh and cost way less than 1GWh of batteries.
Near the arctic circle Wind fill the same niche.