Hacker News new | past | comments | ask | show | jobs | submit login

That is an external energy input.

No one is saying it's impossible to lift water up 1 foot (that's incredibly easy), the problem is it always takes more energy to lift water 1 foot than you can ever get from lowering it 1 foot. Likewise a heat pump can easily and efficiently create a heat reservoir, but you need to drain some other, larger heat reservoir to do so.




Yes, we are explicitly losing free energy from this.

Thing is, the free energy in 60C wastewater is hard to use, and the free energy in 200C steam is much easier to use (through steam-turbines). Hence, it might be worth it to sacrifice a large part of the free energy in the 60C wastewater to get it to a useable form.

What are the alternatives to use 60C wastewater to generate electricity? I can think of a sterling engine or a thermoelectric material. These would probably be more efficient, but they are new technologies, with practical limitations and development limitations. Hence, if my idea could generate any form of electricity, it might be more feasible than the other ideas.

From what I know about heat engines, I know it might not be possible to generate electricity this way.




Guidelines | FAQ | Lists | API | Security | Legal | Apply to YC | Contact

Search: