A Pink Sauna in Sweden Runs on EV Batteries

Skellefteå Kraft, the municipal energy provider in Skellefteå, Sweden, is testing whether a pink sauna can be powered by electricity discharged from electric-vehicle batteries, a demonstration of bidirectional charging.

A sauna painted pink, sitting in a town in northern Sweden, is drawing its heat from the battery of an electric car. That is the whole of the project — and that is the point. Skellefteå Kraft, the municipal energy provider in Skellefteå, is testing whether the stored electricity in an EV battery can run a sauna, and using the result to explain bidirectional charging to people who have never heard the term.

Bidirectional charging, sometimes written V2X for "vehicle-to-everything," means electricity flows both ways through the charge port. A conventional charger only pushes power into the car. A bidirectional one can pull it back out — into a house (V2H), into a single appliance or piece of equipment (V2L, vehicle-to-load), or into the public grid (V2G). The physics has been settled for years. What has not been settled is the commercial plumbing: who owns the electrons, who pays for the hardware, who gets the value, and what happens to the battery warranty.

Why a utility would build a sauna instead of a white paper

Skellefteå is not a random location. It is the town that grew up around Sweden's battery-industrial ambitions, and its municipal utility sits at the intersection of a cold-climate grid, heavy industrial load and a population that already understands what a battery is. Running a sauna — the most Swedish load imaginable — off a parked car is a communications decision as much as an engineering one. A sauna is a big, obvious, continuous electrical draw. If a car battery can hold that up for an evening, the abstraction collapses into something a customer can feel on their skin.

The details of the installation, as reported by electrive, are deliberately simple. The demonstration is about the direction of the flow, not the size of it.

For a utility, the strategic prize behind the stunt is much larger than one sauna. Every EV parked on its network is a battery it did not have to build, sitting idle roughly the whole time it is not being driven. Aggregate enough of them and a distribution company gets something it badly wants: flexible capacity that can be called on at the evening peak, when heating load in a northern town is at its worst and the alternative is reinforcing cables or buying expensive imported power.

The grid economics that decide whether V2G scales

Bidirectional charging only becomes a business when three things line up.

• A price signal worth chasing. The value of discharging a car battery is the spread between the price at which the owner charged it and the price the grid will pay to take it back, minus round-trip losses. Where retail tariffs are flat, that spread is zero and nobody bothers. Where prices swing hard by the hour — as they do in the Nordic market — the arithmetic starts to work.
• Hardware that does not eat the margin. Bidirectional chargers cost meaningfully more than one-way units because they need inverters and grid-protection electronics. The cheaper route is to put the inverter in the car, which is why vehicle-side V2L outlets have spread faster than home V2G installations.
• Rules that let a car be a generator. Metering, grid codes, and interconnection standards were mostly written for fixed assets. A battery that drives away halfway through a dispatch window is an awkward fit, and regulators in most markets are still deciding how to treat it.

The degradation question is the one owners ask first. Every extra cycle on a battery is wear, and no driver wants to trade range in 2031 for a few kronor of arbitrage tonight. In practice the answer is control software: shallow cycling, guaranteed minimum state of charge, and manufacturer-set limits so the vehicle protects its own warranty. That is exactly the sort of thing a demonstration project exists to reassure people about.

What the wider industry has actually deployed

The pattern across the sector is that the easy version of bidirectional charging is now mainstream and the hard version is not. Vehicle-to-load — a socket on the car, powering tools, a campsite, a coffee machine, or a sauna — has become an ordinary selling point on electric pickups and crossovers. Vehicle-to-home, where a car backs up a house during an outage, exists as a supported product in a handful of markets and typically requires a matched charger and switchgear from the automaker or its partner.

True vehicle-to-grid, where a utility or aggregator dispatches thousands of parked cars as a single virtual power plant, remains mostly in pilots — utility trials, school-bus fleets, and workplace-charging schemes. Fleets are the obvious first commercial case, because their vehicles sit still on a predictable timetable and a single owner captures all the value, rather than splitting it between a driver, a charger vendor, an automaker and a retailer.

Northern Europe is the natural laboratory. Hourly electricity pricing is normal, EV penetration is high, winter peaks are severe, and utilities are municipally owned, which makes them more willing to run a project whose payback is measured partly in public understanding.

What the battery supply chain gets out of it

If bidirectional charging becomes a standard function rather than a novelty, the effect on battery demand runs in two directions at once. On one hand, a car that also serves as a home battery erodes some of the market for a separate stationary storage unit — the same cells doing two jobs. On the other, it strengthens the case for larger packs and for chemistries built to tolerate more cycles, which is a demand signal for lithium iron phosphate and for the cathode and anode materials behind it.

It also changes how utilities plan. Capacity that can be borrowed from customers' cars is capacity that does not have to be procured, and that reshapes the pipeline for grid-scale storage projects in dense residential areas. None of that is settled by a sauna in Skellefteå. But the reason a utility builds a thing like this is that the technical case has been made and the remaining barriers are commercial, regulatory and psychological — and a pink box that gets hot on car electricity addresses the third one better than any tariff filing could.

What to watch next

Three markers will show whether this moves from demonstration to product. First, whether automakers extend bidirectional support across mainstream models rather than reserving it for flagships, and whether they warrant it explicitly. Second, whether regulators create a clean route for a parked vehicle to be paid for grid services without the owner needing to become an energy trader. Third, whether utilities like Skellefteå Kraft convert pilots into tariffs a household can sign up for.

Wider markets were quiet on the day the project surfaced. The S&P 500 tracker closed at $763.47, down 0.29%, and the Nasdaq 100 tracker at $706.32, down 1.00%, while the Dow 30 tracker rose 0.27% to $533.65, as of the last trade on Mon, 24 Aug 2026, 20:00 GMT. Nothing about a Swedish sauna moved those numbers — but the flexibility it is advertising is the kind of thing that eventually shows up in power prices.

Key facts

• Project: Pink sauna powered by electricity from EV batteries
• Operator: Skellefteå Kraft, Skellefteå, Sweden
• Technology: Bidirectional charging (V2X), covering V2L, V2H and V2G
• Benchmarks at last close (24 Aug 2026, 20:00 GMT): SPY $763.47 (-0.29%), QQQ $706.32 (-1.00%), DIA $533.65 (+0.27%)

Frequently asked questions

What is Skellefteå Kraft actually testing?

Skellefteå Kraft, the energy provider in Skellefteå, Sweden, is testing whether a pink sauna can be powered by electricity taken back out of electric-vehicle batteries. The project is a demonstration of bidirectional charging, chosen because a sauna is a large, familiar and continuous electrical load that makes the concept tangible to ordinary customers.

What does bidirectional charging mean?

Bidirectional charging lets electricity flow both into and out of an electric vehicle's battery through its charge port. Variants include vehicle-to-load, powering a single appliance or tool; vehicle-to-home, backing up a house; and vehicle-to-grid, where a utility or aggregator dispatches many parked cars as a combined resource.

Does discharging an EV battery damage it?

Extra cycles do add wear, which is why owners ask about it first. The industry answer is software control: shallow cycling, a guaranteed minimum state of charge, and manufacturer-set limits so the vehicle protects its own warranty. Whether automakers warrant bidirectional use explicitly is one of the main things determining adoption.

Why is V2G still mostly in pilots?

Three things have to align: a price spread worth chasing between charging cost and the value of exported power, bidirectional hardware cheap enough not to consume that margin, and grid rules that treat a mobile battery as a legitimate resource. Metering and interconnection standards were written for fixed assets, not cars that drive away.

Which use cases work commercially today?

Vehicle-to-load is already a mainstream selling point on electric pickups and crossovers. Vehicle-to-home exists as a supported product in some markets with matched hardware. Full vehicle-to-grid is largely confined to trials, with fleets the most likely first commercial case because their vehicles sit still on predictable schedules under single ownership.

What does this mean for battery demand?

It cuts both ways. A car doubling as a home battery can displace some demand for separate stationary storage units. At the same time it argues for larger packs and cycle-tolerant chemistries such as lithium iron phosphate, supporting demand for the cathode and anode materials behind them, and it changes how utilities plan capacity.

Sources

• Pink, hot, electric: Bidirectional charging for the sauna — electrive

Photo: Nadja Me · Pexels Licence — source