Consider a power station set up in the middle of a town with cold winters. In the first example it burns has, drives a turbine and cycles water back after some form of basic cooling loop.

In the second example the waste heat (after driving the turbine) is connected to a distributed heating system throughtout the town that heats buildings and pavements and so on. In this case the return loop is much lower temperature, say just above freezing.

In order to do work you need a temperature gradient, although I'm not sure if that is relevant here. On the one had there will be a bigger gradient between the boiled and cooled water, but on the other hand you need to use more energy to lift the temperature from the cooling loop to boiling.

How does the efficiency for purely energy generation compare in these cases?

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[–] 3 points 4 months ago (1 child)

What you're thinking of is called district heating

District heating (also known as heat networks) is a system for distributing heat generated in a centralized location through a system of insulated pipes for residential and commercial heating requirements such as space heating and water heating. The heat is often obtained from a cogeneration plant burning fossil fuels or biomass, but heat-only boiler stations, geothermal heating, heat pumps and central solar heating are also used, as well as heat waste from factories and nuclear power electricity generation. District heating plants can provide higher efficiencies and better pollution control than localized boilers. According to some research, district heating with combined heat and power (CHPDH) is the cheapest method of cutting carbon emissions, and has one of the lowest carbon footprints of all fossil generation plants.

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