General Motors is following Ford into the home power business, using EVs to provide backup power during electric outages.

By 2026, GM intends for all of its new electric vehicles on the Ultium EV platform to be capable of providing vehicle-to-home (V2H) power. Ford offers a similar bidirectional home backup system that draws power from the battery in its F-150 Lightning electric pickup, as does Tesla with the Cybertruck and Volkswagen with some of its EVs. BMW has said it will make bidirectional charging a feature of its new generation EVs starting in 2025.

GM’s power play starts with the 2024 Silverado EV RST, which carries a massive 200-kWh battery pack. That’s enough to power the average American home for about 5 days with 20%, 40 kWh, left to get the truck back on the road.

EVs with vehicle-to-load capability (V2L), such as the Hyundai Ioniq 5, typically provide a maximum energy flow of 1.8 kW, sufficient to power one or two 120-volt appliances simultaneously. The GM system provides 9.6 kW to keep power sucks such as electric ovens and air conditioning and heating systems running.

While the system is available with the Silverado EV RST model, other GM EVs – the 2024 Cadillac Lyriq, GMC Sierra EV Denali and Blazer EVs, and the 2025 Chevy Equinox EV – will need over-the-air or manual software updates in order to be able to share power with a customer’s home. The capability will be built-in by the 2026 model year.

For now, the GM Energy Home System only works with GM products – just as Ford’s only works with Ford and Tesla’s with Tesla. Cross-compatibility depends on the finalization of the long-awaited ISO 15118 standard, which will govern bi-directional and vehicle-to-grid (V2G) communication.

What’s it Cost?
GM V2H system may not make economic sense without an EV. But for anyone who already owns or intends to purchase a GM EV, the home power system can be a relatively inexpensive add-on that provides clean residential backup power without the CO2 emissions of a whole house generator or the cost of stationary storage batteries.

GM Home Power was developed by the recently formed GM Energy unit. The automaker started it in 2022 to bring to market a “suite of charging energy products and services,” GM Energy vice president Wade Sheffer told SAE Media.

Ultimately, GM intends to enable its system owners to earn some money back by charging when power is cheap and selling unused energy to the grid at peak periods when utilities will pay them a premium, said Aseem Kapur, GM Energy’s chief revenue officer.

In addition to the Silverado EV, which lists for $96,495 (less expensive trims will follow), the GM Energy Home System requires $7,299 worth of equipment. Ford’s is around $5,200. This isn’t a DIY system, so Installation could add more than 50% to the total, depending on how many circuits you want on backup power, how long the electrical runs are and whether you need to upgrade your home’s electrical service in order to handle the mandatory EV charger’s maximum draw of 80 amps.

An equivalent whole-house solar backup power system could cost more than $20,000 but doesn’t require EV ownership. Whole house generators that run on natural gas or propane cost considerably less, but are noisier and emit environment-damaging gases.

By the end of 2024, GM Energy plans to make modular storage batteries available and implement solar panel system connectivity that would make the system – like Tesla’s Powerwall – usable without being connected to an EV.

How it Works
GM recently showed off its system at a 10,000 sq-ft (929 sq-m) residence in Beverly Hills, California, that powered critical home elements – lights, ventilation and kitchen appliances – for an entire evening using just a few kW.

The system components were installed on an interior wall of the garage behind a neatly finished pop-out that hid all of the electrical plumbing. If there isn’t sufficient room on a garage or carport wall, everything is rated for outdoor installation as well, William Hotchkiss, GM Energy’s head of safety and quality, told SAE Media.

The proprietary system consists of a $1,699 GM Powershift Charger, a $5,600 V2H Enablement Kit and, available later this year, an optional $5,000, 10.6 kWh modular backup storage battery stack. A 17.7 kWh battery will also be available, and each segment can be purchased separately, so a system can be staged over several years to accommodate budgetary constraints. Additional modules can be added to the backup battery for a total of 35.4 kWh of storage.

There are three parts to the Enablement Kit – the Home Hub, a power inverter and a small “dark start” battery that provides initial power when a blackout hits.

GM Energy’s home system contains a Wi-Fi modem and Ethernet connection that enables remote monitoring and control via the homeowner’s smartphone or computer, along with an electrical panel that connects to up to 200 amps of home circuits. There’s also a controller with the programming and circuitry to identify a power outage, shut down the home’s connection to the grid and order the charger to stop delivering current to the vehicle and start drawing from it.

The bidirectional charger allows the appropriate GM vehicle’s battery to be charged at up to 19.2 kilowatts when connected to a dedicated 80-amp, 240-volt circuit.

The charger will operate with power from the grid or from a home solar panel array. It sends alternating current to the vehicle, where an onboard inverter changes it to direct current for storage in the battery pack. When the system draws power from the battery, at a maximum of 9.6 kW, the inverter in the Enablement Kit changes it back to AC to feed the home’s circuitry.

GM Energy is using Qmerit, a national EV charger installation company, for installation.