There is not much argument now about whether the United States can get to a 100% carbon-free electricity sector in the next 15 years or so. But many still believe that nuclear energy will be needed for the job as a complement to wind and solar. Their arguments center on the following:

  1. It will take too much storage to make up for the variability of solar and wind. Therefore, dispatchable sources are necessary; in particular, nuclear is necessary.
  2. Solar and wind take up large areas of land. It doesn’t take a very elaborate technical analysis to conclude that solar + wind + battery storage is a critical but partial answer to the variability of wind and solar. But the claim that solar and wind therefore need nuclear as a complement derives from a failure to examine the full array of technologies already at our disposal. I’ve spent a few years looking at this issue in depth. The analysis shows that a 100% renewable electricity system based on solar and wind would be economical and also be more reliable and resilient in the face of climate extremes than the electricity system we have today, where centralized nuclear, coal, and fossil gas (aka “natural gas”) plants are the mainstays of supply. It would also be a lot cleaner. You can find most details in a 2016 300+ page IEER report (Prosperous, Renewable Maryland). I’ll give a sketch in this blog and add some new details. We (IEER staff) did hour-by-hour modeling that included the supply needed to electrify transportation and space and water heating, so that CO2 emissions could be reduced from those sectors as well. Efficiency is an excellent starting point, making the system more economical; we factored that in first. We downloaded hourly solar and wind data (onshore and offshore) for various locations and combined them to get an hourly primary supply picture, along with the small amount of existing hydroelectric power (about 2%) in the state. We obtained utility demand data for Maryland and made hourly estimates...