Mechanical power directly for the buildings

This consideration is perhaps way later on the game timeline for the scope it requires.

Power some building directly with mechanical power shaft as alternative to electricity. This would require additional building, like power shafts, direct mechanical engines, like diesel engine to shaft, gas turbines, perhaps later on wind turbines, electric motors as opposed to steam to turbines today.

Electricity conversion in the game from mechanical (from steam) tops out at 83% efficiency. Using mechanical power to the buildings directly would be efficiency, complexity and depth addition to the game.

Lots of buildings just take electricity and convert it to mechanical work again, so they could be good candidates to use power shaft inputs, while taking advantage of lower overall power needed total.

Examples that come to mind today: ore crushers, ore sorters, pumps, mills, storages, train loaders, ship loaders, belts (but spaghetti maze).

Electric motors today are very efficient at making mechanical power too, so it could be an option to have one big efficient electric motor to power entire water pumping-loading hub, mining-sorting-loading hub at better efficiency with mechanical power instead all buildings just requiring electricity.

Yes, this needs expanded power shaft system, expanded buildings inputs, balancing power (mechanical vs electricity) requirements for this all to make any sense. That is why this is just a suggestion for far future branch of expanding game systems for more complexity, efficiency and depth.