The big complaint people have about renewable energy, or at least, the big complaint that has some merit, is that renewables, such as wind and solar, are intermittent and to varying degrees, unpredictably intermittent. This makes it hard to match demand for electricity to supply. Some aspects of this argument are overstated. For example, a steady supply (the same potential power all the time, every minute of the day) can be a bug as well as a feature. If every electron of electricity we used came from nuclear power plants, there would be a problem because our demand fluctuates and you can’t vary the output of a nuclear plant. Some of the arguments are inaccurate. For example, it is not true that a nuclear power plant produces the same exact amount of electricity all the time. Nuke plants often reduce production unexpectedly. If there is some sort of problem, they partly shut down. And, of course, the shut down for refueling. So they are not perfect.
The problem if intermittent and less than ideally predictable supply can be addressed a number of ways. One is big huge batteries, which are costly and otherwise problematic. There are various other storage methods using water and air and things that can hold heat or “hold cold.” And so on. Then, of course, there is the grid. If it is sunny one place and cloudy a different place, electricity can be shunted between.
Still, we often see arguments suggesting that these methods of matching supply and demand of electricity are problematic in one way or another.
A new research project, just out in the Proceedings of the National Academy of Sciences, addresses these issues and gives great hope to the use of 100% non-nuclear renewables to meet energy demands. The paper is by Mark Jacobson, Mark Delucchi, Mary Cameron, and Bethany Frew, and is titled “Low-cost solution to the grid reliability problem with 100% penetration of intermittent wind, water, and solar for all purposes.”
Here is the abstract and the statement of significance from the paper:
This study addresses the greatest concern facing the large-scale integration of wind, water, and solar (WWS) into a power grid: the high cost of avoiding load loss caused by WWS variability and uncertainty. It uses a new grid integration model and finds low-cost, no-load-loss, nonunique solutions to this problem on electrification of all US energy sectors (electricity, transportation, heating/cooling, and industry) while accounting for wind and solar time series data from a 3D global weather model that simulates extreme events and competition among wind turbines for available kinetic energy. So- lutions are obtained by prioritizing storage for heat (in soil and water); cold (in ice and water); and electricity (in phase-change materials, pumped hydro, hydropower, and hydrogen), and using demand response. No natural gas, biofuels, nuclear power, or sta- tionary batteries are needed. The resulting 2050–2055 US electricity social cost for a full system is much less than for fossil fuels. These results hold for many conditions, suggesting that low-cost, reliable 100% WWS systems should work many places worldwide.
The large-scale conversion to 100% wind, water, and solar (WWS) power for all purposes (electricity, transportation, heating/cooling, and industry) is currently inhibited by a fear of grid instability and high cost due to the variability and un- certainty of wind and solar. This paper couples numerical simu- lation of time- and space-dependent weather with simulation of time-dependent power demand, storage, and demand response to provide low-cost solutions to the grid reliability problem with 100% penetration of WWS across all energy sectors in the con- tinental United States between 2050 and 2055. Solutions are obtained without higher-cost stationary battery storage by pri- oritizing storage of heat in soil and water; cold in water and ice; and electricity in phase-change materials, pumped hydro, hy- dropower, and hydrogen.
I’m still absorbing the paper. I’m informed that the authors of this paper know what they are talking about. People I know in the clean energy biz have been saying for some time that they are pretty sure we can do this, and this study seems to support the idea. Even if this is not perfect, it seems that we can be close to using primarily renewables with some contribution from nuclear, and some adjustments in how we use energy. The key message of this work: It is not hopeless, we can save the world! Will we?