In April this year, 25 of the 45 European wholesale power markets went negative at the same time. Poland’s day-ahead price fell to -210 euro per MWh. Germany, Belgium, the Netherlands, Austria, France and Denmark all had hours where the grid was effectively paying people to consume electricity.
Not a one-off accident. It is the predictable result of solar and wind output growing faster than the grid can absorb on the sunniest, windiest days, and it is not going away. Every quarter that renewable capacity grows faster than grid flexibility, these hours get more common, not less.
For a public charging network, that is either free margin or a missed opportunity, and it depends entirely on whether your pricing can see it.
Why a flat tariff is blind to this
If your charger runs on a flat tariff per kWh, it cannot react to a negative wholesale price at all. The driver pays the exact same rate at 2pm on a sunny, oversupplied Tuesday as at 6pm during the evening peak, even though your own procurement cost at that moment might be zero or negative.
That means two things at once. You are not capturing the cheapest power of the month, and you are not shifting any demand into those hours. Charging demand is one of the most flexible loads on the grid, batteries on wheels that can absorb surplus almost anywhere, anytime. A network that does not price for this is missing the chance to be useful to the grid it depends on, on top of missing the margin.
The tempting fix that is not quite right
The obvious next move sounds simple: link your tariff directly to the wholesale price and pass it through one to one, spot price plus a fixed margin. When the market goes negative, drivers pay less. When it spikes, they pay more. Problem solved.
Except this is exactly where a lot of operators get hurt. This model already exists in Proxilink, we call it flat + spot internally, and we already ran the numbers on a real destination charger with an afternoon peak. Result: roughly 4% less profit than a plain flat tariff (see the full breakdown of all five pricing models).
Flat + spot tracks the spot price one to one, with zero sense of demand. On a charger where occupancy peaks during the solar dip, that means systematically discounting drivers who would have shown up anyway.
A tariff built purely on the energy price has no demand awareness. It can end up cheap exactly when you are already full, and expensive exactly when you need to attract sessions. On top of that, your margin now moves entirely with a volatile market: fine on a calm day, painful on a rough one, and genuinely dangerous if a price spike lands during your busiest hour or a data feed hiccups. Treating a purely spot-driven tariff as the rate every driver pays is not the safe, simple version of dynamic pricing. It is the version with the least protection built in.
Where an energy-price tariff actually earns its keep
There is a real place for a tariff that moves purely with the wholesale price. It just is not as the default rate for every driver who plugs in.
The better place is as a discount, reserved for members. Join the network, and your rate automatically tracks the wholesale price, so on days the grid is oversupplied you pay noticeably less, sometimes close to nothing. That is an easy story for a driver ("plug in when the grid has too much power, and you save"), and a strong reason to become a member instead of paying the standard rate as a one-off visitor. The exact volatility that makes it risky as a base tariff is what makes it a compelling reason to sign up, and once someone joins, the discount simply gets switched on for their account.
That leaves the tariff every other driver pays free to do what it should: react to actual demand at that site, not to whatever the wholesale market happens to be doing. The two are not in competition. A demand-aware base tariff protects your margin and your utilisation. A wholesale-linked member discount captures negative-price hours as a real, felt benefit, and turns that into a reason to sign up.
Why this is bigger than one unusual month
April 2026’s numbers are striking, but the underlying trend, more renewable capacity, more oversupply hours, more negative pricing, is structural. A network whose pricing cannot react to this in 2026 will be leaving proportionally more on the table in 2027. The question is not whether to build for it. It is whether you build it as a blunt, all-or-nothing base rate, or as a sharper discount layer that rewards the people who actually signed up.
We wrote earlier about why a flat tariff is the real transparency problem. This member discount follows the same logic: not adding complexity for its own sake, but putting the right layer on the right problem.
Negative-price hours are a real opportunity, not a footnote. But the fix is not handing every driver a tariff that moves one to one with a volatile market. The fix is letting a demand-aware base tariff do its job, and using the wholesale-linked version for what it is actually good at: a membership perk that turns a genuinely cheap hour into a genuinely good reason to join.
Frequently asked questions
Why are negative electricity prices becoming more common in Europe?
Negative prices happen when solar and wind output outpaces demand on the grid, typically on sunny or windy days. Because renewable capacity keeps growing faster than grid flexibility every quarter, these hours are becoming more frequent, not less. In April 2026, 25 of the 45 European wholesale markets went negative at the same time.
Why is it risky to link your charging tariff directly to the wholesale price?
A tariff that only tracks the spot price has no sense of demand at your site. It can end up cheap when you are already full and expensive when you need customers, while your margin is fully exposed to market volatility. In our own backtest, that model performed roughly 4% worse than a flat tariff.
So what is the right place for a wholesale-linked tariff?
As a discount layer for subscribers, not as a base tariff. Members get a rate that automatically tracks the wholesale price, so they pay noticeably less on oversupplied days. That is also a strong reason to become a member.
Does this mean non-member drivers pay more?
No. Their rate stays the demand-aware base tariff, independent of this discount layer. The wholesale-linked discount is an extra benefit on top of that base tariff, reserved for those who sign up, and does not change what other drivers pay.