Energy harnessed from the sun, wind, or water is a lot cleaner than it is reliable. When it comes to tapping these energy sources, somedays are better than others.
To make matters worse, humans consume just as much electricity, if not more, on cloudy and windless days than they do on sunny or breezy days. Because of this, civilization's grid will continue to rely on dependable but finite amounts of coal and nuclear energy.
That is, of course, until we collectively find a breakthrough in energy storage. To put it more succinctly, improved batteries that last a long time.
On that note, McKinsey's in-house think tank predicts that the price of lithium-ion battery packs could fall by a third in the next 10 years, which will have a big impact on not only electric cars, but storage of renewable energy in general.
But it will take more than just falling prices of existing technology to finally flip the switch on renewable energy. "New energy storage technology will be a critical part of any renewable energy supply, which typically are sporadic relative to demand," says Brian Ingram, an energy storage researcher for the U.S. Department of Energy. To fill the "troughs" of unreliable renewables, he says, smarter batteries must first be developed.
The bad news is we still have a long ways to go. The good news is there are lots of smart people working on solving the problem, including the Joint Center for Energy Storage Research, where Ingram and several of his award-winning peers are hard at work.
For example, the center has achieved significant improvements to lithium-ion batteries over the last 15 years, the most reliable batteries we've created to date. "Just as lithium-ion batteries 15 years ago enabled portable electronics, we have seen a dramatic cost reduction per storage kWh to power short-range electric vehicles and many are predicting the price could drop below this threshold in the next several years," Ingram says, echoing McKinsey's findings.
"Additionally, there have been many scientific discoveries in the last 15 years beyond lithium-ion." Some of those discoveries include non-aqueous flow and multivalent (i.e., magnesium ion) batteries with extended range, as well as a resurgence of lithium-sulfur batteries.
On top of that, Tesla's battery expert Dr. Jeff Dahn and his team have recently reduced the moving parts in lithium-ion batteries to extend both the range and storage of its car batteries, and long duration flow batteries are increasingly encroaching on lithium-ion's dominance.
Assuming our greatest minds can someday improve our battery technology then, might there ever be a time when people aren't plagued by low energy warnings on their portable devices and vehicles?
Probably not, Ingram says. After all, humans have been limited in their exploration of the world and beyond, by the amount of energy we can bring with us. "Whether it's sustenance for nomads, gasoline for road trips, or nuclear generated energy for space exploration, the demand for more energy consumption constantly drives the scientific and technology development for batteries."
But that doesn't mean it won't get better or that we'll soon be able to ditch those pesky battery expansion packs you've increasingly encountered while traveling. "Today's batteries are significantly better than those only 5 years ago and we anticipate a similar level of improvement in the coming years," Ingram concludes. "Despite limits to the amount of energy that can be stored in a certain volume – we all hope to be untethered from our power outlets."