From Knowable Magazine, December 18:
When the Sun doesn’t shine and the wind doesn’t blow, humanity still
needs power. Researchers are designing new technologies, from reinvented
batteries to compressed air and spinning wheels, to keep energy in
reserve for the lean times.
When the Sun is blazing and the wind is blowing, Germany’s solar and wind power plants swing into high gear. For nine days in July 2023, renewables produced more than 70 percent of the electricity generated in the country; there are times when wind turbines even need to be turned off to avoid overloading the grid.
But on other days, clouds mute solar energy down to a flicker and wind turbines languish. For nearly a week in January 2023, renewable energy generation fell to less than 30 percent of the nation’s total, and gas-, oil- and coal-powered plants revved up to pick up the slack.
Germans call these periods Dunkelflauten, meaning “dark doldrums,” and they can last for a week or longer. They’re a major concern for doldrum-afflicted places like Germany and parts of the United States as nations increasingly push renewable-energy development. Solar and wind combined contribute 40 percent of overall energy generation in Germany and 15 percent in the US and, as of December 2024, both countries have goals of becoming 100 percent clean-energy-powered by 2035.
The challenge: how to avoid blackouts without turning to dependable but planet-warming fossil fuels.
A January 2023 snapshot of Germany’s energy production, broken down by energy source, illustrates a Dunkelflaute — a long period without much solar and wind energy (shown here in yellow and green, respectively). In the absence of cost-effective long-duration energy storage technologies, fossil fuels like gas, oil and coal (shown in orange, brown and dark grey, respectively) often pick up the slack during such periods.
CREDIT: FRAUNHOFER INSTITUTE FOR SOLAR ENERGY SYSTEMS ISE
Solving the variability problem of solar and wind energy requires reimagining how to power our world, moving from a grid where fossil fuel plants are turned on and off in step with energy needs to one that converts fluctuating energy sources into a continuous power supply. The solution lies, of course, in storing energy when it’s abundant so it’s available for use during lean times.
But the increasingly popular electricity-storage devices today — lithium-ion batteries — are only cost-effective in bridging daily fluctuations in sun and wind, not multiday doldrums. And a decades-old method that stores electricity by pumping water uphill and recouping the energy when it flows back down through a turbine generator typically works only in mountainous terrain. The more solar and wind plants the world installs to wean grids off fossil fuels, the more urgently it needs mature, cost-effective technologies that can cover many locations and store energy for at least eight hours and up to weeks at a time.
Engineers around the world are busy developing those technologies — from newer kinds of batteries to systems that harness air pressure, spinning wheels, heat or chemicals like hydrogen. It’s unclear what will end up sticking.
“The creative part … is happening now,” says Eric Hittinger, an expert on energy policy and markets at Rochester Institute of Technology who coauthored a 2020 deep dive in the Annual Review of Environment and Resources on the benefits and costs of energy storage systems. “A lot of it is going to get winnowed down as front-runners start to show themselves.”
Finding viable storage solutions will help to shape the overall course of the energy transition in the many countries striving to cut carbon emissions in the coming decades, as well as determine the costs of going renewable — a much-debated issue among experts. Some predictions imply that weaning the grid off fossil fuels will invariably save money, thanks to declining costs of solar panels and wind turbines, but those projections don’t include energy storage costs.
Other experts stress the need to do more than build out new storage, like tweaking humanity’s electricity demand. In general, “we have to be very thoughtful about how we design the grid of the future,” says materials scientist and engineer Shirley Meng of the University of Chicago.
Reinventing the battery
The fastest-growing electricity storage devices today — for grids as well as electric vehicles, phones and laptops — are lithium-ion batteries. Recent years have seen massive installations of these around the globe to help balance electricity supply and demand and, more recently, to offset daily fluctuations in solar and wind. One of the world’s largest battery grid storage facilities, in California’s Monterey County, reached its full capacity in 2023 at a site with a natural-gas-powered plant. It can now store 3,000 megawatt-hours and is capable of providing 750 megawatts — enough to power more than 600,000 homes every hour for up to four hours....
....MUCH MORE
The problem has been known for decades.
Here's a 2016 post referring back to a 2012 post:
Bill Gates: "It Is Surprisingly Hard to Store Energy"Yes, yes it is.
And that's why storage is the Holy Grail for VCs.*
*****
*Oddly enough, in 2012's "Batteries: The Venture Capitalist's Holy Grail" I mentioned a different Holy Grail:
...Microsoft famously didn't need venture capital either.
(Technology Venture Investors was the sole VC investor and got that plum only because Marquardt and Ballmer were buddies)
That's the Holy Grail, finding a company that doesn't need you but will let you in.See also:
The battery on the other hand....that's going to be a longer slog than the press releases would lead one to believe.
Gates, Pritzkers vs. Musk: "The $5 Billion Race to Build a Better Battery" (TSLA)for some of our posts on batteries.Or, if interested use the 'search blog' box upper left.
