Letter: Any sustainability plan should start with energy audit

PORTLAND PRESS HERALD • December 2, 2021

I appreciate all the current discussions on climate change and our efforts to develop a sustainable human society on planet Earth. I have yet to see, however, a definition of a sustainable system in any scientific journal or media source. Allow me to propose this definition: A system is sustainable if, over its lifetime, it captures and stores more energy than it consumes in its creation, operation and maintenance. In practice, this definition requires that we measure the energy inputs to the system and the energy outputs from the system in all its facets (an “energy audit”). I am open to commentary on and challenges to this definition – but let us not go blindly into any proposal for sustainability without conducting a thorough energy audit. ~ Derek Libby, Freeport