Providing 100 Percent Energy from Renewable Sources is Impossible

Published February 12, 2020

Lately, many politicians at the federal, state, and local levels have unthinkingly bought into the talking points of radical environmentalists, pushing policies to require 100 percent of the electricity used in the United States to come from politically favored renewable energy sources, primarily wind and solar power.

Generating all of America’s electric power through wind and solar industrial facilities is an expensive pipedream.

Intermittency Is Renewables’ Hallmark

One main reason the 100 percent renewable goal is impossible is the extreme intermittency of wind and solar power.

Industrial wind facilities have been pushed the hardest by politicians as a source of “cheap,” renewable power, so it is important to realize they commonly generate little to no power for an entire week. To supply the missing power from backup batteries is unbelievably expensive, if it could be done at all.

Batteries, especially at the scale needed to “supplement” renewable generated electricity, carry an astronomical price tag, making anything even close to 100 percent renewables economically impossible. At today’s prices, the batteries required to back up an industrial wind facility would cost about 250 times as much as the wind facility itself. So even if the price dropped substantially, the cost would still be prohibitive.

It is not just a matter of the wind not blowing sometimes; it is that the wind rarely blows enough for sustained maximum electricity production. A standard wind farm supplies full power only when there is a sustained wind of more than 30 miles per hour or so. This is a rare event almost everywhere in the United States. More importantly, little to no power is generated below 10 miles an hour, a more common occurrence.

This is why wind farms generate only about 35 percent of their rated capacity on average. They almost never generate their rated power, and they often generate none at all.

Planning for the Worst Case

In order to provide reliable power, we have to consider what might be called the common worst case: most often stagnant, high-pressure weather systems. Such systems have little wind, because wind is caused by significant pressure differences and these do not occur under the high-pressure, more common systems. Low wind systems often last a week or longer. Moreover, such weather systems typically cover huge areas, so all of the wind turbines spanning multiple states are often idled simultaneously.

Let’s do the math. A 100 Megawatt (Mw) wind farm (one-tenth of the 1,000 MW farms under construction) might cost $100 million to build. A week has 168 hours, so to back up this little farm we need 16,800 MWh of electricity storage for each week. According to the Energy Information Administration, the average cost for a utility-scale battery storage facility is about $1.5 million dollars per MWh. At that cost, the batteries for this hypothetical wind farm would cost an astounding $25.2 billion.

Building a $25 billion dollar battery system just to back up a $100 million wind farm would be foolish in the extreme, even if we knew how to do it, which at present we don’t. The biggest battery facilities built today can only store a few hundred MWh, not tens of thousands. These little battery systems are not built for backup storage; they are built for short-term grid stabilization, which wind power also requires.

Problems with Scale

A 100 MW wind farm is minuscule compared to what is needed for 100 percent renewable power on a large scale. Colorado currently requires about 10,000 MW of power during summer peak use times, which is often caused by these stagnant highs. The batteries for such a project might cost something like $2.5 trillion, which Colorado certainly cannot afford.

Ironically, Colorado is home to the National Renewable Energy Laboratory, staffed by the world’s largest collection of renewable energy experts. They must know 100 percent—or anything near it—is impossible. Yet Colorado’s governor is calling for 100 percent renewables by 2040, just 20 years from now. It simply cannot be done—not even close.

Colorado, of course, is small compared to the United States as a whole, where peak demand is several hundred thousand MW.

In addition, if electric vehicles become widespread, which is part of the larger plan for 100 percent renewable energy, the need for electricity could increase by 30 percent or more.

The battery backup requirements would be staggering. Do sufficient raw materials even exist? And how would we dispose of the huge amounts of toxic waste that would result?

False Claims Rife

You might ask, “What about all the towns and companies boasting they are buying 100 percent renewable electricity?” This is a legal fiction. They are simply buying green certificates claiming somewhere, sometime, an amount of renewable energy was or will be generated equal to what they are using. None of it is generated by wind farms on low-wind days or by solar facilities at night.

It is likely most of the electricity these folks are using is not from renewables at all but rather from traditional sources such as fossil fuels, hydroelectric, or nuclear.

Even if battery costs dropped to a tenth of what they are today, it would still be prohibitively expensive to do anything like 100 percent renewable energy on a large scale. There is simply no way to store that much backup juice.

As a result, the 100 percent renewable goal is impossible. Politicians pushing policies requiring it ought to be called to the carpet for doing so.

David Wojick, Ph.D. ([email protected]) is an independent analyst working at the intersection of science, technology, and policy.