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Book Review: Power Density, A Key To Understanding Energy Sources and Uses

A review of the book Power Density, A Key to Understanding Energy Sources and Uses, by Vaclav Smil.  Available from MIT press.


  • Power density—expressed in a form that accounts for the spatial requirements of energy extraction, conversion, and use—is critical to understanding paths forward for energy transitions.
  • Physical space matters in the calculation and consideration of impacts, beginning with the fuels we use in our energy systems.
  • It is impossible to achieve full conversion from today’s energy system to a fully renewable system within 15 to 35-years, the timeframe of many countries’ current GHG reduction targets.
  • It would more effective to focus on the three conditions and investments necessary for a future renewable energy system:
    • a marked increase in the efficiency of all final energy uses;
    • discovery and use of large-scale electricity storage to manage challenges with renewable flows; and
    • support for innovations aimed at affordable use of electricity to produce liquid fuels.

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