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Energy is Wasted, Wasted, Wasted...

by Michael Graham Richard, Gatineau, Canada on 04. 7.08
Science & Technology (alternative energy)

Energy Lost Graphs

A little while ago we posted some very cool graphs by the Lawrence Livermore National Laboratory that showed how much of the energy produced gets wasted, and how much ends up doing useful work. Well, it seems like the New York Times got hold of these stats and graphs and gave them a face-lift to make them easier to understand for the average person.

See below for a bigger version.

Energy Graphs

For comparison, here's the more detailed graph from the Lawrence Livermore National Laboratory:

Efficiency graph

::New York Times

See also: ::Efficiency is Crucial to a Green Future, ::Efficiency Works Forever, ::Department of Energy Creates Energy Star Criteria for Water Heaters

Comments (5)

Yep, so much waste it makes my head swim.

jump to top buzz saw says:

That's why RMI (Rocky Mountain Institute for those who don't know) emphasize downstream efficency (final stage where energy is used), because if you have a system that by the end of it is 10% efficent (possibly even optimistic for electricity useage), saving 1 unit of energy at the end saves 10 units of energy throughout the system.

jump to top Dan A says:

Where did the comments go about not being able to beat the laws of physics? Who is monitoring this and why are the comments gone?

jump to top greendoughnuts says:

The level of waste is shocking. But these are complex systems with several steps that needed to be mass produced...the trade-offs and "lower common denominator" effect would naturally drive down the overall efficiency. Is anyone aware of a proven system that's in production on a mass scale that is significantly more efficient than these numbers?
Kent

jump to top Kent Ragen says:

I abhor any amount of waste, but I think these figures may be blown out of proportion. One must realize that, due to entropy, no thermodynamic cycle can me more than around 50% efficient. In order for energy to flow, energy must be wasted. The Carnot cycle has the theoretically highest possible efficiency and cannot actually be achieved in practice. All thermodynamic systems must be judged on this standard. When you say an engine is 35% efficient, that is 35% of Carnot. So the engine is really only converting about 18% of the heat into useful work. These descriptions are very general and the thermodynamic calculations are actually based on temperature differential and calculus.

So, it seems like the figures are based on total heat generated, not total usable heat. Of course, that waste heat could be used to heat water or for some other low-grade energy use, but it can never (and will never) be used to generate power.

I say use the electricity for important things, not heating water or homes. Use the waste heat that is usually blown out of cooling towers to heat a municipal hot-water loop and pipe hot water into people's houses. What's the use of burning coal to heat water to drive a steam generator to create electricity to be piped into people's homes to power a resistance heater to heat more water? I never understood that.

So, in closing, yes the heat is technically being wasted, not in the way the article is leading the reader to believe.

Luc

jump to top Luc says:

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