The Green New Deal Meets Physics
April 11, 2019
A new report by the Manhattan Institute explains that while greater efficiencies can be gained by electric generators using solar or wind energy, technology will soon bump up against hard stops in those efforts. See The “New Energy Economy”: An Exercise in Magical Thinking (March 26, 2019). https://www.manhattan-institute.org/energy-environment For example, the so-called Betz limit will prevent wind turbines from converting more than 60% of available wind energy to electricity, and current technology is already able to harness over 45% of that energy. Likewise, the Shockley-Queisser Limit prevents more than about 33% of the photons reaching a solar cell from being converted into electrons, while existing technology can already achieve about 26% efficiency. So, the many-fold increases in output that we have come to expect from computer chips is not just around the bend in energy generation.
Further, the battery technology available to store power generated by renewables for usage at convenient times is not only expensive but will depend on a many-fold increase in mining for the materials needed to produce them. None of these technologies hold any realistic chance in the short-term of providing the efficiency that exists in fossil fuels, and any effort to rely on them will dramatically increase electricity costs. In the meantime, without new transformative technologies, efforts to achieve CO2 targets demanded by some would require much less electricity usage—an issue that will likely create an impossible political hurdle for the Green New Deal. To put it in perspective, the authors of the new report say:
This daunting challenge elicits a common response: “If we can put a man on the moon, surely we can [fill in the blank with any aspirational goal].” But transforming the energy economy is not like putting a few people on the moon a few times. It is like putting all of humanity on the moon—permanently.
This report is worth a read by anyone who thought this would be easy or even reasonably possible in the foreseeable future without an extraordinary reduction in electricity usage that is likely politically impossible. The authors of the report have suggested that more money should be spent on basic research to find alternative sources of energy than continuing to believe that support for the marginal increases available using existing renewables will achieve desired CO2 reductions.