Energy efficiency refers to how much useful output is delivered based on input. For thermal energy generation, net efficiencies tend to range from 20% to highs of about 40--50% via combined-cycle generation, perhaps with cogeneration of generation+thermal heating applications, the latter typically being district heating or industrial heating.
There's also the concept of nameplate capacity vs. capacity factor. The former relates to the maximum possible output of a facility, the latter to the attainment of the nameplate capacity over a year.
It's not clear to me which of these you're referring to.
Moreover, the conversion efficiency of flows such as solar and wind is not directly comparable to the efficiency losses of termal generation for other reasons, namely that the environmental availablity of the uncaptured portion is still generally available for other environmental service. Burning a ton of coal and only extracting 30% of the total energy potential still means you've incurred an opportunity cost of 70% of that fuel stock's energy potential.
I will note that there are a lot of shenanigans which are played with nameplate and capacity factors, by both boosters and opponents of renewable / carbon-neutral energy. That said, there's no need to add to the confusion.
Confounding conversion efficiency, capacity factor, and deadweight opportunity costs and losses is a slippery business at best.
There's also the concept of nameplate capacity vs. capacity factor. The former relates to the maximum possible output of a facility, the latter to the attainment of the nameplate capacity over a year.
It's not clear to me which of these you're referring to.
Moreover, the conversion efficiency of flows such as solar and wind is not directly comparable to the efficiency losses of termal generation for other reasons, namely that the environmental availablity of the uncaptured portion is still generally available for other environmental service. Burning a ton of coal and only extracting 30% of the total energy potential still means you've incurred an opportunity cost of 70% of that fuel stock's energy potential.
I will note that there are a lot of shenanigans which are played with nameplate and capacity factors, by both boosters and opponents of renewable / carbon-neutral energy. That said, there's no need to add to the confusion.
Confounding conversion efficiency, capacity factor, and deadweight opportunity costs and losses is a slippery business at best.