There's also a bunch of supporting equipment, so maybe they used around 500W * 1023 * (34*24=816)hrs = 417,384kWh?
I think that would be around $35k in fossil fuels, assuming none of the datacenter's energy came from renewable sources?
A more reasonable estimate might be 5 years * 500W * 1,000 systems = 76.7 GWh, ~29.3kWh * 55% = 16.1 kWh. Actual electricity generation isn’t 100% natural gas but this is additional demand on the grid which tends to be supplied by natural gas unless there’s a surplus of green or nuclear power. Also, data centers also use AC etc so it’s really quite arbitrary how you want to estimate things.
PS: A similar thing applies to EV’s people tend to use the existing mix of generation to estimate how green they are but it’s not like we are adding hydroelectric dams when people increase electricity consumption. It’s really a question of how marginal increases in demand are supplied.