How does the efficiency of a power station compare to the efficiency of an internal combustion engine?
depends on the cycle used, scale does play a part too, as bigger machines can usually do things “slower”/more efficiently, and often have bigger heat exchangers etc, but it’s not exponential, and is due more to slight shifts in the relationship between “cost and payback” here’s a short list of thermal efficiencies (thermal efficiency=useful energy out/total energy in) otto cycle (petrol engine) =upto about 25% diesel cycle (diesel engine) =up to around 35% depending on size/speed of engine Rankine cycle (steam generator cycle) =about 42% in practise Cogeneration (Combined heat and power) = about 89% total. somewhere like 35% efficient at producing electricity and the rest is “useful” heat such as steam for heating) NB nuclear power stations use rankine cycles, but are less efficient because of extra heat exchangers used to prevent radiation entering the turbines. it’s perhaps a little fairer to try to consider “like for like”, so should really consider the effect of transporting power
IC ingne is a single component and its efficiency is high. A power station is combination of many…like a coal based thermal plantthe components shall be boiler, steam turbine, generator, transformer and the efficiency of power stations shall be combination of all. e.g. if the efficiencies of boiler, steam turbine, generator, transformer (if provided) are 50%,95%,97%,and 99% respectively, the efficiency of power station shall be 50x95x97x99 = 45.6%whereas the ic engine may have an efficiency of 75%. If the power station uses ic engine as prime mover of the generator, the power station efficiency shal be product of IC Engine and generator (and transformer if provided) efficiency.
