The Oil Drum

Thanks for the efforts, Engineer.

I assume that the presenter subtracted all the emergy these "waste" materials contained.

Because, as you know, it would be considered thermodynamic cheating to say that this waste stream somehow constituted a new "source" of energy.

It's like this. You use fifty gallons of energy equivalent to make, let's say, a small powerboat. This includes all the processes of mining, transportation of raw materials, manufacture, feeding the workers, transporting the workers, building the factory, building the roads to the factory, building the electrical lines to the factory etc. Now the boat represents fifty gallons of spent fuel. A lot of this energy must have been expended as waste. There is no possibility of any product representing 100 percent of the energy used to make it.

You then run it through the process you described above. It produces energy because there is embodied energy available. You must, of course, subtract any energy inputs from the building of the plant and the running of the plant. So. Of the original 50 gallons of embodied energy, you get, what? One gallon?

Okay. So, what we have here is a ridiculously elaborate method of recycling. You might claim we are recycling energy. I would argue that if you took the small power boat and refurbished it at a much smaller energy cost, you would effectively save the emergy of building a completely new boat which would equal a savings of 50 gallons of energy equivalent minus the energy cost of the refurbishing.

Now, one can look at this "solution" in two additional ways:

First: Let's say we decide to use it as is. We could mine all of the dumps in the world and burn up those monuments to energy inefficiency as well as burn up those materials which poop out the end of our horrendously inefficient consumer beast. This process will last until the feedstock, which are the dumps and the inefficient detritus from our fossil fuel cycle are gone. Then it stops.

Second: We could still burn up the dumps, but instead of continuing our stunningly wasteful manufacturing processes, we could build processes designed according to the principles outlined in "Cradle to Cradle." This would mean no waste stream from our industrial processes, which is as it should be. But, once the dumps are mined and the fossil fuel used up, the game is up.

Of course, my standard concerns regarding the rest of our resources being depleted before we could ever get to the end game of the above processes still hold.