From the local electricity grid. A charger has no power of its own: it draws from the same distribution network that runs the lights, through the property’s metered utility service — usually via a transformer. A home charger taps that grid through your house panel; a DC fast charger taps it through a much larger commercial service.
Key Takeaways
- Chargers generate nothing — each draws from the local grid through a metered service connection.
- The path runs generation, distribution, service and meter, transformer, then the charger.
- Home and public charging use the same grid — what differs is the size of the tap.
- Your electricity’s generation mix is the grid’s mix at that hour; contracts and timing are the levers you control.
The Path From Grid to Battery
| Stage | What happens |
|---|---|
| Generation | Power stations and renewable generators feed electricity into the grid |
| Transmission and distribution | The utility moves power at high voltage, stepping it down at substations to local lines |
| The site’s service and meter | A service connection brings power in; the meter records everything the site uses |
| Transformer and switchgear | Voltage is set to what the building and chargers need; large sites often have their own transformer |
| The charger | Level 2 passes AC to the car, whose onboard charger converts it; DC fast charging converts AC to DC inside the cabinet |
The session steps a public charger runs once you plug in are covered in how EV charging stations work; this article is about the supply behind them.
Home vs Public: Same Grid, Different Size of Tap
Your home charger shares the house’s service with everything else. That is why installation starts with the panel: EV charging counts as a continuous load under the National Electrical Code, so the breaker is sized at 125% of the charger’s current — 48 A on a 60 A breaker.
A public DC fast charger is a different scale. The U.S. DOT puts DC fast charging at 50–350 kW, so a corridor site needs a commercial service, and often a transformer, sized for several cars at once. The supply work — not the hardware — is frequently the slowest, most variable part of commercial station installation costs, which is why operators plan the feed before choosing the posts.
So Whose Electricity Is It? The Mix Question
Drivers often ask whether their car runs on coal, wind or solar. The honest answer is: on the local grid’s mix, at the moment you charge. Electricity in the network is pooled — a charger cannot pick out particular electrons, and neither can a house. What you can choose is the contract and the timing: some tariffs buy renewable generation for you, time-of-use prices push charging into less-strained hours, and rooftop solar feeds the same pool. The pairing is set out in our guide to solar panels and EV chargers.
The Two Exceptions Worth Knowing
- Battery-buffered stations. Some sites add a large battery. It fills slowly from the grid, then helps serve cars faster than the service connection alone could — the grid is still the source, time-shifted.
- Mobile and off-grid charging. Roadside-assistance vans and remote setups carry energy in batteries or make it with a generator. They exist for emergencies and gaps.
What This Means in Practice
- A power cut stops charging. A charger waits for the grid like everything else. Federal corridor rules hold stations to average uptime above 97% — about equipment and maintenance, not immunity from outages.
- Supply capacity decides what can be installed — it is the first question in any installation survey.
- Sized-right equipment beats oversized equipment. A charger matched to the supply beats a nameplate the feed cannot support.
Equipment choice follows from it. The EVDANCE EV-RHDC30K-L compact DC fast charger delivers 22 kW DC for sites whose service could never feed a corridor-class unit, and the EVDANCE EV-AC03201T dual-connector AC station shares up to 43 kW across two cars inside one capped supply. The commercial charging solutions page maps classes to site types.
Frequently Asked Questions
Do fast chargers have generators or big batteries inside?
Ordinarily, no — it is conversion equipment on a large grid service. Some sites add a battery to shave peaks, but the energy still comes from the grid.
Can a charger run purely on solar panels?
A grid-tied solar home still draws from the grid pool; panels offset what the property uses rather than feeding the charger directly. Charging straight from panels alone is a special setup, not how chargers normally work.
Why did every charger at a site stop during a local outage?
Because all of them share the site’s supply. When the line goes down, the chargers have nothing to draw until the utility restores the feed.
Related Reading
- How Do EV Charging Stations Work?
- How Do Commercial EV Charging Stations Work?
- How Much Does It Cost to Install a Commercial EV Charging Station?
- Solar Panels and EV Chargers: How to Charge Your Car With Sunshine
