The scale, first, because it is genuinely striking
A mid-sized electric vehicle carries somewhere in the region of 60 to 100 kilowatt-hours. The largest portable power station on this site holds just over two.
Put another way: the car in the driveway holds roughly thirty times what a 2kWh battery does, and it is already paid for.
At a household critical load of 1.5 to 2.5 kWh a day, a full EV battery is theoretically weeks of backup power. That is why the idea gets so much attention, and why the practical constraints matter so much.
Three letters decide whether you can use it
| Capability | What it does | What you need |
|---|
| V2L — vehicle to load | An AC outlet on the car, or an adapter on the charge port, that runs appliances directly | A supported vehicle and usually a manufacturer adapter |
|---|
| V2H — vehicle to home | The car back-feeds the house through a transfer switch, like a standby generator | A supported vehicle plus a specific bidirectional charger and an electrician |
|---|
| V2G — vehicle to grid | The car exports to the utility grid, usually under a program | All of the above plus a utility that offers it |
|---|
| Neither | The pack cannot be discharged externally at all | Nothing helps — this is most vehicles currently on the road |
|---|
Support varies enormously by manufacturer, model and model year, and it changes between years within the same nameplate. We deliberately do not publish a compatibility list here because it would be wrong within months — check your specific vehicle's manual and your manufacturer's current documentation.
The honest headline: most electric vehicles on the road today cannot export power, and a large pack you cannot discharge is not backup power. Find out which category yours is in before planning around it.
What V2L actually gives you
Where a vehicle supports it, V2L is usually a household outlet — either built into the car or provided through an adapter that plugs into the charge port.
Practically that is a large, quiet, already-charged generator sitting in the driveway. Its limits:
- The outlet is rated in the low thousands of watts on most implementations. That covers a fridge, lighting and electronics — not central air or electric heating.
- It is outside. You are running extension cords from the driveway, with all the same gauge and length considerations a generator would have.
- It cannot reach hardwired circuits. The furnace, the well pump and the sump pump have no plugs, so V2L does not touch them.
- The car cannot leave while it is powering things.
- Manufacturers often reserve a floor. Many systems stop exporting at a set state of charge so you are not stranded.
For a household whose critical list is refrigeration, lighting and communications — which is most households — V2L covers it for days without touching the driving range meaningfully.
V2H is a different, larger project
Vehicle-to-home back-feeds the house properly, through a transfer switch, the way a standby generator does. That means hardwired circuits work, no cords run through doors, and the changeover can be automatic.
It also means an installation:
- A specific bidirectional charger, matched to the vehicle. These are not interchangeable.
- A transfer switch or interlock so the car cannot energize the utility line — the same backfeed problem a generator connection has, with the same solutions.
- Permits, an electrician and an inspection.
- Utility notification in many jurisdictions, because you are installing a device capable of exporting.
Cost-wise this sits closer to a standby generator installation than to a power station purchase — and unlike a standby generator, the power source drives away when someone takes the car to work.
The honest objections
- The car may need to leave. In a wildfire shutoff or an evacuation, range is the thing you least want to have spent. A battery that stays home does not have this conflict.
- Battery wear. Cycling a traction pack for household loads uses cycles, and warranty treatment of export use varies by manufacturer. Read yours.
- You cannot refill it. An outage takes the public chargers down too. Unlike a generator with a fuel can, what is in the pack is what you have.
- Cold weather costs range twice — once to the household load, once to the reduced capacity.
- Compatibility changes. A capability that exists on this year's model may not on last year's.
What we would actually recommend
If your vehicle supports V2L: use it, and pair it with a modest battery indoors. The car refills the battery twice a day, the battery runs the house, and the car stays free to drive. That arrangement removes almost every objection above at the cost of one mid-sized power station.
If your vehicle supports V2H and you own the house: it is a serious alternative to a standby generator, with the standing caveat that the power source is also your transport. Get quotes for both and compare on total installed cost.
If your vehicle supports neither: which is most people — buy backup power the ordinary way. The pack in the driveway is not available to you, and no adapter makes it so. Start at the beginners guide.
One thing worth adding regardless of category: an EV is a very good reason to have a plan for charging it during a long outage, and the honest answer is usually that you cannot. Keeping the car above half charge through a storm season costs nothing and is the single most useful habit here.
