Blackout: The Role of Electric Cars When the Lights Go Out

A power outage can turn your day upside down. Things you normally take for granted stop working, and it can bring a great deal of inconvenience and stress. Heating stops, and food goes bad. And sharing updates about the awful situation with your friends over WhatsApp or Instagram becomes complicated since every percent of your phone battery is suddenly precious.

What happens if the power stays off for more than a few hours, and could your electric car help? Find out here.

The combination of ageing infrastructure, cybersecurity threats, extreme weather events and rising electricity demand has made the system more fragile than many people realised. While countries do take precautions, such as Germany introducing § 14a EnWG, where the grid operator can control your high-power devices, blackouts still occur.

Why the blackout risk is rising:

• The ageing grid infrastructure struggles to handle peak loads

• Cybersecurity and sabotage threats 

• Extreme weather events 

• Geopolitical tensions affecting energy supply

Two recent examples show how bad it can get.

At the start of 2026, parts of southwest Berlin were left without electricity for several days. Thousands of households suddenly had to cope without heating, hot water or working lifts. Shops closed. Remote work became impossible. Even charging a phone — something you never have to really think about — turned into a problem.

Less than a year earlier, on 28 April 2025, a large-scale blackout affected some parts of Spain and Portugal. In some regions, it lasted more than ten hours. Trains and metros stopped mid-route, traffic lights failed, and mobile networks and internet services went down. Elevators stalled with passengers inside.

Yes, an EV can help during a blackout, but with limitations. An electric vehicle won’t replace a power plant. However, under the right conditions, it can act as a temporary energy source for a household.

If a power outage occurs and your car battery is charged to 80% or more, you can use it to power some of the most essential home appliances, such as lights or the fridge. Ideally, though, you also have a PV system at home. This allows you to recharge the battery once the sun is out, using surplus solar power and then use that stored energy in the evening to keep your home supplied with electricity.

A single street with 20 EVs can represent over 1.5 MWh of storage. That’s enough to keep a local grocery store’s freezers running and power about 800 energy-efficient LED streetlights on for an entire weekend. By using EVs to store excess wind and solar, cities can retire fossil-fuel "peaker plants" that usually kick in during high demand, reducing a city's carbon footprint by up to 25%.

Unlike a central power plant, which is a single point of failure, 10,000 EVs spread across a city are impossible to "knock out" all at once, providing a robust safety net against both technical failure and cyberattacks.

In practice, however, this capability is still limited. Although the technical foundation for bidirectional charging largely exists, full interoperability between vehicles, wallboxes, home energy systems and grid operators is not yet standardised across Europe. In particular, AC bidirectional V2H and V2G charging based on ISO 15118-20 is still undergoing standardisation, and many systems rely on proprietary solutions. This means that in 2026, reliable backup power still depends on compatible systems.

Electric cars can supply power in different ways. However, not every function equally helps in a real blackout. Some bidirectional charging options are useful for charging small devices, others can supply parts of your home with energy, and some mainly support the public grid to prevent a potential power outage.

You can plug in appliances like a fridge, a kettle or a laptop charger directly into your car using an adapter. Models such as the Hyundai IONIQ 5 and 6, the Kia EV6 and several BYD vehicles already support this. It’s practical, but limited since V2L does not feed electricity into the household wiring. So, for instance, your central heating or built-in systems won’t automatically run.

Requirements:

• An EV that supports V2L functionality

• A compatible V2L adapter (usually supplied by the manufacturer)

In pilot projects in Austria (e.g. Raasdorf), EVs equipped with V2L technology can be used to supply electricity directly to mobile phone base stations. Normally, these base stations have emergency batteries that last only about 30 - 45 minutes. After that, the communication infrastructure becomes vulnerable.

A single EV can power a cell tower for up to twelve hours, depending on battery size and load management. During emergency operation, energy consumption is reduced (e.g. throttled data speeds, lower frequencies) to make sure that essential communication services remain available.

The car can supply electricity directly into the building’s electrical system. However, this is only possible if the home is properly prepared for backup operation. In the event of a grid failure, the property must be disconnected from the public grid using a certified transfer switch. This prevents dangerous backfeeding into the grid and protects utility workers. In addition, an “island mode” (backup mode) configuration is required so the home can safely operate independently while the public grid is down.

In island mode, the home still needs a stable electrical signal (voltage and frequency, e.g., 50 Hz), similar to what the public grid normally provides. A backup system, such as an inverter or gateway, creates this signal. It allows household devices to run normally and ensures the V2H/V2B system can supply power safely while the home is disconnected from the public grid.

Requirements:

• An EV with bidirectional (V2H) capability

• A compatible bidirectional charger (wallbox)

• A transfer switch for safe grid isolation

• Island mode configuration to operate independently from the public grid

This type of bidirectional charging allows cars to send electricity back into the public network. However, V2G does not function as a personal backup. It is typically used to help stabilise supply during peak demand, so it is basically there to prevent power outages. In a full blackout, grid safety rules prevent feeding power into a network that is down.

Requirements:

• An EV that supports V2G

• A V2G-compatible bidirectional charging station

• Grid operator approval and compliance with local regulations

• Smart energy management system

• Active public grid connection (does not function during a full blackout)

In an emergency, most people are not trying to power everything. The focus shifts to basics such as keeping food cold, maintaining some lighting, charging devices and running heating controls.

Here’s what your daily power needs could look like:

• Refrigerator 1.2 - 1.8 kWh 

• LED Lighting (~5 rooms) 0.5 - 1.0 kWh 

• Wi-Fi, Laptops, Phones 0.4 - 0.8 kWh 

• Furnace fan / Well pump 4.0 - 8.0 kWh 

So, the total daily essential is around 12 kWh. In many homes, consumption during a blackout falls somewhere between 10 and 15 kWh per day.

A compact EV with a 40 kWh battery could cover these electricity needs for about three days. Vehicles with batteries in the 60 - 80 kWh range extend that to roughly five or six days. Larger battery packs, around 90 kWh, stretch the timeframe further.

• Renault 5 E-Tech (40 kWh): ~3 days

• Hyundai Kona Electric (64 kWh): ~5 days

• Tesla Model 3 RWD (60 kWh): ~5 days

• Tesla Model Y Long Range (81 kWh): ~6.5 days

• Kia EV6 / Hyundai IONIQ 5 (77.4 kWh): ~6 days

• Ford Mustang Mach-E (91 kWh): ~7.5 days

Of course, real-world results depend on factors such as temperature, the battery’s state of charge, the presence of a PV system (and, in that case, the daily weather conditions), and how carefully electricity is used.

Even if your EV can’t run the whole house or you don’t have a full V2H setup, you can still find a use for it in a blackout. The car itself becomes a kind of mobile safe space.

Modern EVs are relatively energy-efficient at heating or cooling the cabin compared to running household heating systems. If your apartment is freezing in winter (or scorching hot in summer), you can simply sit in the car with the heater or AC running. Charge your phone, turn on the radio, and stay comfortable for hours. Usually, you use only a small percentage of the battery for those things.

VW’s Stenberg Project (Sweden) uses ID. cars in Island mode to power apartment essentials. Utrecht enables EV microgrids to share solar energy. Nissan’s Blue Switch deploys its Leafs as mobile batteries for medical aid in disasters.

Keep in mind that these projects demonstrate technical feasibility, but they are still pilot or controlled deployments. They rely on coordinated infrastructure, defined standards and close cooperation among manufacturers, grid operators and regulators.

In Sweden, Volkswagen partnered with a housing cooperative in the Stenberg project. A fleet of ID. models was configured to support apartment buildings during grid failures. If the surrounding network goes down, the system switches the building into Island mode (disconnects from the public grid). Instead of total darkness, corridor lighting stays on, and elevators continue operating.

In Utrecht, bidirectional chargers have been integrated into neighbourhoods to form small microgrids. When power goes out, cars with full batteries can feed electricity back into nearby homes. This means refrigerators keep running, phones remain charged, and residents can stay connected while technicians work on restoring the grid.

Japan provides another example through Nissan’s “Blue Switch” programme. It includes cooperation agreements with hundreds of municipalities. During earthquake-related outages in early 2026, Nissan Leaf vehicles were sent to evacuation centres. In places where fuel deliveries were delayed, and generators had stopped, the cars powered medical devices, lighting and communication equipment. 

Lithium-ion batteries have limited cycle life. Well, nothing lasts forever, so that’s no big surprise. But the situation is actually better than many assume. Studies show that smart bidirectional charging causes minimal wear. The Mobility House and RWTH Aachen University studied how bidirectional charging affects EV batteries. They found that when charging and discharging are managed carefully, using small cycles and moderate charge levels, the long-term impact on battery health is minimal.

Work from the University of Warwick (WMG) even indicated that smart Vehicle-to-Grid strategies can slightly extend battery life. By avoiding prolonged periods at 95 - 100% state of charge, which contributes to calendar ageing, the battery may last even longer.

With lithium iron phosphate batteries becoming more popular, the situation gets even better. These cells, used in mass-market models like BYD Atto 3, MG4 and Dacia Spring Electric, can handle significantly more cycles (often 2,000 or more) with comparatively low degradation.

EVs typically store far more energy than standard home batteries, allowing them to power essential appliances for days rather than just a day. At the same time, it’s a vehicle you’re likely purchasing anyway for mobility.

This means you get transportation and high-capacity energy storage in one device. In everyday life, it keeps you moving. During a blackout, it can help keep your home running (with the right charging setup).

* This requires the PV system to be capable of operating independently of the grid (island mode).

No, electric cars do not cause blackouts. Current research indicates that even if every personal vehicle in a country like the UK or the US were replaced with an EV overnight, total electricity demand would only increase by approximately 10% to 25%. In addition, this growth is not happening overnight. It is a phased adoption that aligns with ongoing multi-billion-dollar grid modernisations.

EV owners can also actively support grid stability:

• Load shifting: With a smart wallbox, charging can be automatically scheduled during off-peak hours (times when overall electricity demand is low) rather than during peak periods.

• Peak shaving: This intelligent feature reduces the charging power during times of high grid demand, preventing additional strain on the system.

• V2G: Feeding electricity back into the grid can effectively turn thousands of cars into small, distributed batteries that help balance supply and demand.

As EV battery capacities grow and bidirectional systems develop, they can offer flexibility and a greater sense of security. If you want to get clarity on which bidirectional charging setup fits you, think about whether you are looking for simple emergency support or full home backup: 

• V2L – For quick, plug-and-play backup.

Power a fridge, charge phones and laptops, run LED lights, a coffee machine or your Wi-Fi router — essentially any appliance that operates via a standard 230V socket. In an emergency, you can even use your EV’s stored energy to supply certain medical devices. 

• V2B – For supplying electricity to commercial buildings.

Keep office lighting on, maintain IT infrastructure and servers in the building, power supermarket refrigeration, operate elevators in apartment buildings, or support critical infrastructure like pharmacies or small medical practices during grid failures.

• V2H – For powering essential parts of your home during an outage.

Run your heating controls, circulation pumps, selected sockets, lighting circuits or even a well pump. Your home must be equipped with a compatible charger and island-mode setup.

• V2G – For supporting the public grid and earning potential flexibility benefits.

Not a direct blackout backup.. Feed stored energy back into the grid during peak demand to help stabilise load fluctuations.

In a prolonged outage, EV bidirectional charging capability can mean the difference between slight inconvenience and real struggle. A warm room, functioning communication and preserved food are not luxuries during a crisis.