I remember back in the 1980s watching a news broadcast reporting about waste heat like in the train tunnels. Yeah I remember in the train tunnels suffering from the heat generated by air conditioning and hot power relays during the summer. In winter I love the train tunnels because it shelter me from the extreme cold up above.
It would have been an interesting idea to see how to capture the waste heat for power generation by viewing all the sources it comes from. It would transform how we design things that uses energy when we must think about ways to capture the waste energy.
The argument by my brothers was about how much input energy was put in capture vs how much power is generated. The failure of the argument was about how to think up ways to concentrate or capture the waste heat without costing too much. Much like fusion, it cost more to keep up the reaction than the power it generates.
It seems 30 years later various forms of the technology has been popping up.
If we had worked on the technology seriously in the past, qe would not have wasted so much of resources we crave for.
I saw on the news about using the heat differential of seawater to generate power. they developed an improved heat exchangers to heat up a liquid with low boiling point to generate steam to power a turbine.
http://english.ryukyushimpo.jp/2013/06/14/10571/
Developments in waste heat technology
http://www.350resources.org.uk/2013/04/16/developments-in-waste-heat-technology/
Germany uses train tunnel heat to heat up apartments
http://www.detail-online.com/architecture/topics/heating-energy-from-a-tunnel-019276.html
It seems that we need to think about how we use energy while we must think about making use of its waste.
ie: We heat up iron ore to make steel ... we don't think about capturing the waste heat
ie: The heat in tunnels we don't think about lining it with pipes to carry away the heat into an ante chamber above that will generate power.
ie: Vehicles running the combustible engine we don't think about capturing the heat
ie: The coal power plants ... the waste heat from the sut
Something learned .,. if we use liquids that have lower boiling points ... then we can use less resources to power our generators.
ie: Coal, oil, natural gas would be used less of
ie: nuclear power plant could have more generators to make use of extra steam thats generated from the low boiling point liquid