One of your ideas, to use the heat from air conditioners, makes sense and has many applications. The other, to generate free electricity, turns out to violate basic laws.
You're absolutely right that the heat output of the air conditioner coils is several times larger than the energy used. With an efficient commercial system, that factor can be more than five. You can buy heat pump systems that work as air conditioners in the summer and in reverse, pumping heat into a house, in the winter. Those are much more efficient than simple electrical heaters. Even when the electrical power comes from fossil fuels, they can be more fuel-efficient than gas heaters, especially in mild climates. Since electrical power can also come from cleaner sources than fossil fuels, heat pumps can become really big improvements over other heating systems.
So the general idea of pumping heat rather than just generating it is indeed correct. It should be much more widely used in order to reduce the need for fossil fuel use.
The idea of using an electrically powered heat pump to boil water to drive a turbine to generate electricity will never work, however. The energy output is always less than the input, for fundamental reasons.
It's not particularly practical even to use heat pumps instead of electrical coils to boil water. The reason is that the efficiency of the heat pump drops as the temperature difference between the hot and cold sides gets bigger. That's the same reason that houses with heat-pump heating systems need some backup heaters if they are located in places with serious winters.
Mike W.
(published on 07/10/2012)
