> A lot of our modern use of energy is inefficient-by-design: the system is designed to 'use as much energy as possible'. Obviously not. Systems are generally

> A lot of our modern use of energy is inefficient-by-design: the system is designed to 'use as much energy as possible'. Obviously not. Systems are generally designed for lowest total cost of ownership. If fuel is cheap and capital expensive, it can make sense to 'waste energy', counterintuitive as that may sound, if that enables lower capital costs. Of course, what goes into the TCO is also a question of debate. Including externalities like pollution and climate change, and suddenly the optimal point might shift considerably. > Why don't we have more cogeneration systems, where the waste heat is used instead of released? Because cogeneration systems, or rather the district heating networks, are capital and maintenance intensive and make sense only in relatively densely built areas with significant heating demands. Where they make sense they are awesome, though.