Ignorance of the Law is no excuse: Thermodynamics part 2

It’s apparently Perpetual Motion Day today on the web. Following up my rambling about the Second Law of Thermodynamics and business models that claim to “create value,” I spotted the following two articles. Can you see the common theme?

  • CNet: Getting gas from trash. “The two by-products of from digester would be methane, a liquid fertilizer, and solid compost. Eten envisions selling each of the products wholesale…. Eten said he was inspired by William McDonough, a designer who co-authored a book called Cradle to Cradle, which argues that a product lifecycle can be designed with little, or even beneficial, impact on the natural environment.”
  • BBC: Natural light “to reinvent bulbs.” “Previous attempts to make OLEDs like this have largely failed to make an impact because traditional phosphorescent blue dyes are very short lived. The new polymer uses a fluorescent blue material instead which lasts much longer and uses less energy. The researchers believe that eventually this material could be 100% efficient, meaning it could be capable of converting all of the electricity to light, without the heat loss associated with traditional bulbs.”

Yes, folks, trying to violate the Second Law of Thermodynamics as a core part of your business plan is probably a bad idea. In the first case, it’s certainly laudable to try to do something about garbage production, but the question is: can selling methane, compost, and fertilizer produce enough money to offset transportation and holding costs? Probably if the raw material is free… but there’s no free ride in the world and I would expect waste management companies or the supermarkets providing the raw material to eat up any profit margins to be had from converting their wastes to usable products.

In the second case, the researchers have either been misquoted or neglected their thermodynamics education. Heat is always a byproduct of the translation from one form of energy to another, unless that translation does no useful work at all.