Scientists Argue Over 100% Renewable Energy Feasibility—and It’s Fascinating

Let’s face it—science isn’t always exciting. Scientific journal articles aren’t beach reading, at least for most of us. But right now there is a heated public debate among scientists over the feasibility of achieving 100% of U.S. energy by 2055–and it’s fascinating!

Flashback to 2015: Dr. Mark Jacobson of Stanford University publishes his findings in the Proceedings of the National Academy of Science that a low-cost, 100% renewable (wind-water-solar) energy system is possible in the U.S. by 2055. His work is often cited by renewable energy advocates when confronted with the challenges of achieving this level of renewables.

Last Monday, a group of 21 leading researchers published a critique of Jacobson’s findings, prompting a series of rebuttals back and forth between the two camps (as well as some pretty interesting comments in online forums).

A key premise of the critique is that Jacobson makes assumptions about the ability to scale-up everything from hydropower to energy storage in ways that are not realistically possible, including 27x for solar power, 113x for storage (excluding hydrogen), 33x for wind power.

The faults identified in the critique have been summarized well by several media sources, so I won’t go into great detail here. A few highlights of issues raised include:

  • The assumption that energy storage systems will be able to store enough energy to power the U.S. for seven weeks, while currently, the 10 largest systems in the U.S. have a combined storage capacity of only 43 minutes.
  • The inclusion of an increase in hydropower of 10 times the current maximum capacity, through the addition of more turbines at existing dams. This increased capacity would only be used 10% of the time or less, during low- wind and solar production periods.
  • A lack of modeling of the electricity grid to determine what new transmission would need to be built and where.
  • A gross underestimation of the cost of increased hydrogen production and storage systems.

Even if Jacobson’s model were technically sound, there is the question of political feasibility. A scale-up of this magnitude would require a mobilization of resources not seen since World War II. All while the President, EPA Chief, and head of DOE question basic climate science.

Consider the state of Pennsylvania, for example. Attempts continue to be made to weaken the state’s energy efficiency law, Act 129, despite its proven track record of success. It is hard to imagine the type of policy interventions needed to enact the level of transformation Jacobson suggests is possible.

Considering these arguments, it’s important to distinguish between electricity and energy. While some larger, developed countries are achieving higher and higher percentages of renewable electricity, reaching these same levels in transportation, heating, and industrial processes, will likely be more difficult.

Jacobson, in his response, argues that his detractors are focused solely on carbon emissions as a metric, ignoring other environmental and societal benefits. Maybe that’s true. However, climate change threatens every aspect of our lives and will exacerbate every environmental challenge we face. Perhaps it deserves to be the primary metric by which plans are evaluated.

The core question we face is how much are we willing to bet. Proponents of the 100% renewable vision argue that every great inventor, from the Wright Brothers to Steve Jobs, was told his idea was impossible until he dared to create it. Personally, this argument always makes me feel like a stick in the mud for not being visionary or thinking outside the box.

However, when it comes to climate change, the stakes are incredibly high. Because we did not take serious action on climate change earlier, we don’t have the luxury of time to start down one path, realize it’s not working, and start over. We are literally betting the house. Should we gamble everything? Or instead pursue a more balanced approach, such as that put forth by the U.S. Mid-Century Strategy for Deep Decarbonization, that allows for the use of existing nuclear, bio-energy, and carbon capture and storage, in addition to a scale up in renewable sources?

While much of PEC’s work involves advancing renewable energies (in fact, the office I’m sitting in as I write this is powered with 100% wind energy) we believe a portfolio approach using all available zero-carbon energy sources is more prudent. The encouraging aspect of this no-doubt ongoing debate is that it has entered the mainstream, bringing more attention to the issue.