If you have a machine which is worthless after 3 years, then if you only run it for 12 hours a day rather than 24 then it costs twice as much per hour in deprecation.

If your machine costs $1000 to buy and $1 a day for 24 hours to run with a lifetime of 1000 days, then the total cost is $2000 to generate 24,000 hours of output, or 8 cents an hour.

If you run it for 12 hours your cost drops to $1500 to generate 12,000 hours of output, or 12 cents an hour.

You could of course just add batteries to your solar. A 5GW power plant in the south of the US, add 10GW or 20GW of solar, add 60GWh of battery storage, in summer export excess to grid (when there's a lot of demand for AC), in winter you could import a small amount from grid, or run smaller amounts of energy.

The capital cost is way below the cost of the equipment you're powering, and land is less than a rounding error. If you don't have the grid then just don't export the excess power, or use it to give free EV charging to locals