Geothermal Generators have always been game-breaking. Not because they're OP in their own, since they are quite balanced if you use small Lava Lakes but bcause of people exploiting the Nether.
In an other hand, it seems ridiculous to nerf Lava while Oil (BC OP-ness ...) generate that much energy. I mean, just for "realism", it's too weird to me to imagine Charcoal generating more energy than what Lava contains ...
That's why I would like to suggest a whole new system, that would buff Lava efficiency but making more difficult to build insane powerplants in the Nether.
Basically, I think a GUI system would be cool, and would permit the balance I'm looking for.
So I would suggest the following system:
Lava contains tons of energy, based on its Temperature. To convert this Lava into energy by cooling the Lava down, you would need:
Pipes to contain the Lava.
Pumps/Engines to move it.
Heat Exchanger to cool it down and then Heat Water/Get energy (depending on the fact you wanna use Steam or generate EU directly, as it is with Nuclear Reactors)
Output and Input components to make the Lava enter or exit the generator.
The balance mechanism would be:
-The more you cool down the Lava, the more you get energy, but the colder it gets and so: the harder you'll gain efficiency (Thermodynamic efficiency = (T(Lava)-T(Water))/T(Water) ) and the harder you'll move the Lava.
Basically, this would mean you can extend the length of your pipe (aka putting more "pipe components" adjacent between an input and an output) to get more energy from Lava (the first exchanger would be the more efficient, due to the Thermodynamics laws I told about already, and the last one would generate less energy/heat less water), but this will also require more pumps to move the Lava, which is less room for other things ... such as several pipelines in your GUI.
If there aren't enough pums, the pipes will overflow (too much Lava) OR just block (Lava being too slow) and you'll have to repair it later.
So having the highest possible output wouldn't only mean have lots of components (that shouldn't be low tech IMO) but also decreasing Lava efficiency. Of course several output and input of lava (+ the pipe between those 2) with their exchanger would be cheaper than several Geothermal Generators though.
Then, using Lava as a high-voltage powerplants as it is currently massively done in the Neter would mean a low efficiency (or at a way higher cost), like 6000 EU/Lava Source ... and then you wouldn't use the Heat left and you would get Obsidian.
