France has already racked up about 800 hours in 2026 when wholesale electricity prices were zero or negative.
What stands out just as much is what that volatility means for battery operators, which can charge when prices plunge and sell electricity back when prices climb.
Here's what to know
The Electric Viking (@electricviking), a YouTube creator focused on electric vehicles and energy, revealed in a video that since January 2026, nearly 12.5% of France's wholesale power-market hours have landed at zero or below.
He opened the video: "For more than a month this year, electricity in France has been free. Literally free. Actually, no. Cheaper than free."
The rise of this phenomenon has been sharp, per the Electric Viking. France logged roughly 150 negative-price hours, and in 2025 the total was just over 500.
During the May 1 holiday, when offices and factories were closed, wholesale prices fell as low as negative 56 cents per kilowatt-hour, which the video said was the market floor. At levels like that, generators are effectively paying buyers to take electricity, the creator said.
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September offered another example of how wide the swings have become. On an average day, the cheapest hour was below 4 U.S. cents per kilowatt-hour, while the most expensive reached 28 cents. That constituted nearly an eightfold difference and the biggest daily spread since the 2022 energy crisis.
More background
The main driver is timing. As the Electric Viking put it, France is "swimming in solar" at lunchtime, while evening prices are often being set by gas plants, with fuel costs still high.
Nuclear power also was not enough to fully close that evening gap. During the European summer, heat, drought, and even a swarm of jellyfish knocked out more than one-fifth of nuclear output, leaving less cheap electricity available after dark.
When the grid is flexible enough to use it, inexpensive midday solar can be a big win for consumers, helping reduce the cost of EV charging and other electricity-heavy activities.
Without much storage, though, some of that value is lost as prices crater instead of the power being held for later use.
What's being done?
Adding more storage is the most obvious fix. France began 2026 with only about 1.5 gigawatts of grid batteries, which the video said was roughly one-quarter of the solar capacity added in 2025.
Because storage is still limited, a standard grid battery that charged during midday price drops and sold power around dinnertime saw earnings jump 135% in September, according to the video.
That kind of arbitrage can help stabilize the grid while putting abundant renewable electricity to better use.
For consumers, around 11 million homes on off-peak plans are having part of their cheap overnight window shifted to a summer midday block from 11 a.m. to 5 p.m., making it easier to run dishwashers or charge EVs when electricity is cheapest.
In France, Renault 5 owners can sign up for a program the video described as free charging, in which the car charges when electricity is cheap and feeds some power back when the grid needs it.
"The real problem here in France is not too much solar, it's not enough batteries," the Electric Viking argued.
Where can I learn more?
France's price swings are part of a broader shift as solar surges and storage starts to catch up across the grid.
• Across Northwest Europe, solar-flooded power markets pushed electricity prices below zero during a heat wave.
• In France, 95% clean electricity is giving customers a growing cost advantage.
• Utilities are testing peer-to-peer energy trading to help households cut bills and balance demand.
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