Part of the output of a generator producing electricity is lost due to the Joule effect. This could be used to obtain aerostatic thrust from an aerostat. If it is possible and really effective, several configurations can be studied.
In the vast majority of applications, however, it is an undesired effect and the reason why electrical and electronic devices need heatsinks, apart from one or more fans that scare away the heat generated and thus avoid excessive heating of the different components and / or devices. In these cases, heat is lost energy and therefore a decrease in efficiency.
Instead of losing this heat while generating electricity, is it not possible to recover and direct it to heat, even slightly for a very large balloon, a closed envelope?
That said the same website mentions also:
For example, in electric motors where electrical energy is transformed into mechanical energy, an efficiency can be defined as the ratio between electric power (Joule I · V law) and mechanical power, even if currently the most efficient electric motors they do not exceed 50% efficiency due to the electrical resistance of copper, the best existing conductor, the possibility of greater efficiency has been demonstrated with motors with superconducting windings. Therefore, it is possible to conceive a reversible transformation in which all electrical energy is transformed into mechanical energy.
An example of a study of a superconducting wind turbine generator:
The cost can be high, and perhaps usual generators making loss by Joule effect can be more suitable for the described use.
Maybe you can do some calculations of heat loss from a sample generator and from a (steam) aerostat, weight, lifting capacity, and so on and compare that to using, say, a hydrogen aerostat where you include the cost of buying “green” hydrogen.
I still like my idea, or perhaps combined heating and electrity generation, better, but then on the ground.
What’s the efficiency of the generator of a large wind turbine? 80 percent seems low. And how heavy is it?
I don’t think a steam or hot air aerostat is possible. Because of the wind loading you have to inflate it to higher than atmospheric pressure, and with that you’ve lost all your lift, and it’ll fail because of the hoop pressure. Only possibility I can think of is perhaps if you construct an inflatable double-walled shell around it, but that’s also a much poorer solution than any other to lift things. Or perhaps not one single balloon but many closely stacked together, or as a multilayered shell, keeping the warmth in, but then envelope weight multiplies.