Post by Paul Martin

According to Google, I coined the term "primary energy fallacy". I've been talking for quite a long time, alongside people like Jan Rosenow and Michael Liebreich, about how those who would convince us that the transition is impossible because such a huge fraction of our primary (input) energy still comes from the burning of fossils, are committing the 2nd Sin of Thermodynamics. When you compare a joule of chemical potential energy in a fuel (which is a proxy for heat) against a joule of mechanical energy or electricity as if they're equal in value, you sin against the 2nd Law by ignoring the concept of exergy. As Michael puts it, "all joules of energy are created equal, but some joules are more equal than others!". Mechanical energy and electricity are pure exergy, i.e. thermodynamic work, and can easily be converted into other forms of energy with comparatively high efficiency. Not so with heat- the 2nd Law sets limits on how much heat can be converted into work. 2/3 of the primary energy in fossil fuels is wasted as waste heat, in transitions from chemical potential energy to work. The likes of Vaclav Smil, and even well-meaning people like the late David Mackay who wrote the essential "Sustainable Energy Without the Hot Air", made this error of simplification- treating joules as if they were equal. And that leads us to wrong conclusions about the transition. That's the primary energy fallacy in a nutshell- looking at the transition with a fossil fuel lens, ignoring the fact that renewable electricity is already pure exergy. When you look properly at how we will deliver useful energy services, i.e. comfortable homes, transporting goods and people, providing light and industrial heat etc., the transition away from wasting fossils for their lowest value use to humankind- as fuels- looks about 1/3 as hard as it does through Smil's eyes. https://lnkd.in/eKrz8VrN