At this point, I’d wager that pretty much everyone in the US either has been affected or knows someone who has been affected recently by a natural disaster-related electric power outage. Often the households dealing only with a power outage, and not also fire, flood, or freeze directly threatening their lives and property, are the lucky ones. That doesn’t reduce the hardship of a power outage. Indeed, for people who use electric-powered medical devices, a power outage is life-threatening. And then there is all the wasted food if the refrigerator is off too long. Tossing the contents of a warmed fridge and freezer would be an inconvenience for some, while it can have serious consequences for those experiencing food insecurity. The power outage hardship list could go on.
Fortunately, there are solutions to both make the electric grid more reliable and provide backup power to homes and businesses when the power does go out. One such solution is integrating electric vehicles (EVs) into home power systems and into the grid itself. To do that, EVs must have bidirectional charging capability: the ability to charge both ways with an EV, both charging the battery from the electric grid or a local generation source and discharging electricity from the battery to power something else. That “something else” could be another power load, such as a device or a whole home, or it could be the grid.
Bidirectional charging capability is beginning to pop up in some EV models, and policies such as California’s S.B. 59 could bring this opportunity to more drivers. More on that shortly. First, I’ll share a personal example.
You or someone you know needs clean backup power
Walking my dog the day after Hurricane Milton swept through my Orlando, FL neighborhood, the rumble of fossil fuel-powered generators interrupted what would have been a welcome quiet after the storm. And there was also the smell of burning fuel in the generators, block after block after block. I’d estimate one out of every two or three houses we passed had a fossil fuel generator going.
I don’t blame them. My neighbors were most likely using their generators to run refrigerators, equipment for cleaning up debris, perhaps even life-sustaining medical equipment while we were without electricity. I might have been doing the same thing but for living on an upper floor of an apartment building without an exterior space to run the generator (which is required if you don’t want to poison the air inside your home). Instead we made do by putting our perishable food on ice, making coffee with the JetBoil propane burner we have for camping (in an outdoor stairwell), and keeping the blinds closed to keep the apartment as cool as possible.
Plus, we had a fully charged EV in the parking garage where we could charge our phones or cool off for a bit if the apartment got too hot. We did not have to lean on our EV battery because the power came back on after about 12 hours, but we sure were glad to know it was there for us if we needed it.
Walking through the din and stench of all those fossil fuel generators, I thought of my UCS colleague who has bemoaned a similar phenomenon. For him, it is the sound of fossil fuel generators, rising like clockwork following the start of a public safety power shutoff (for wildfire prevention) in his Oakland, CA neighborhood.
An EV can be a backup battery on wheels
Fossil fuel generators have been the status quo, but there is a better way to power a home during an outage—batteries. Unlike a fossil fueled generator, a battery is silent and will not pollute the air in your neighborhood. A permanently installed power bank is one option, and that might be the best one for households with large or critical electric needs, such as medical devices. For many other households, a serviceable and cost-efficient option is a multi-purpose battery—an electric vehicle, which is a battery on wheels. That is, if the EV has bidirectional charging capability.
While my colleague and I are fortunate to each have an EV battery that can provide power for our devices, it is annoying to think our cars could be doing so much more for us when the power goes out—if only they could be easily set up to provide power directly to our homes, often referred to as vehicle-to-home or V2H.
With both bidirectional charging capability in the vehicle (both hardware and software) as well as the corresponding setup in the home, V2H could power homes the way our neighbors currently use fossil fueled generators.
We need easy, off-the-assembly-line V2H options, included
In addition to the USB and three prong outlets inside of the vehicle, my Hyundai Ioniq 5 did come with vehicle-to-load (V2L) capability through charging port. But that requires an adapter (sold separately, of course), and the V2L isn’t designed for providing the level of power to run a home. It’s better suited for V2L at a campsite, for example. Vehicle-to-load, by itself, can be a lifeline, as was recently the case for a Georgia driver in the after math of Hurricane Helene. And the limitations of V2L haven’t stopped some motivated drivers from running an extension from the V2L adapter to a generator inlet in their garages for off-grid use.
Side note: my most acute barrier to doing effective V2H is living in an apartment building. I don’t have access to or authority to make changes to my electrical panel, even if I were able to get the EV close enough to plug an extension cord directly into a generator inlet in my electric panel. Apartment housing is a tough nut that needs cracking to unlock V2H for back-up power, as well as vehicle-to-grid opportunities for those who would like to participate.
My Oakland colleague’s Chevrolet Bolt doesn’t even have the capability to send power back out of the charging port.
Some EVs, such as newer General Motors models and the Ford F-150 Lightning, do come with the option to add on a home backup system installation. But even for the Lightning, bidirectional charging is not universal on all trims. Drivers of lower trim Lightnings have to pay a software activation fee to enable home backup bidirectional capability.
We need automakers to provide bidirectional charging capability, regardless of price point and vehicle category, to make backup power (as well as the potential to participate in vehicle-grid integration programs) an option for all EV drivers. This is particularly important to ensure access for drivers who buy on the used vehicle market (where most households procure their cars). Drivers buying new EVs can choose a vehicle model and trim that has full bidirectional capability if they want it. Drivers buying used EVs have less control. Their choices are limited by what comes on the used market. Hence the need for full bidirectional charging capability on all EVs, and that’s where regulations can help by standardizing such capability.
California’s Senate Bill 59 is an important step toward universal bidirectional charging capability
UCS sponsored S.B. 59* to set the stage for a bidirectional capability requirement that can break down the key barrier to doing V2H. The bill, signed into law at the end of September, gives explicit authority to the California’s Energy Commission to set a requirement for bidirectional charging capability in EVs, from the moment they come off of the assembly line. Under such a requirement, more and more EVs on the road would transition to having full bidirectional capability over time. That will unlock the option for EV backup power, as well as the option to support the electric grid, for more and more drivers, regardless of whether they buy new or used.
As significant as S.B. 59 is, there is much more work to be done. To begin with, we need the agency to initiate a rulemaking for bidirectional charging. Then we need to shape the rule to be as beneficial to drivers as possible, including preserving some vehicle and battery warranty protections for drivers who choose to use some of their kilowatt-hours to back up their homes or participate in vehicle-grid integration opportunities.
California policies have helped move the US vehicle market before, and I am hopeful they can do it again. For it is not only California drivers who stand to benefit from bidirectional charging requirements—many, many of us EV drivers across the country would benefit from using our batteries on wheels for more than just getting around. Our households need clean backup power.
*The bidirectional charging bill was originally SB 233.