Electricity might be generated with Diesel generators. The efficiency of these small devices is relatively low but small improvements lead to significant fuel savings. In case operational control will happen manually the real load needs to be adjusted to the generator capacity.
Electricity and heat might be generated with Combined Heat and Power Plants. These systems need high investments and pay only off in case operating times are adjusted to individual needs and tariff structure in place. As framework conditions change continuously there is a constant need for updated operational control.