My spouse and I work at home and after the first couple multi-day power outages we invested in good UPSs and a whole house standby generator. Now when the power goes out it's down for at most 30 seconds.
This also makes self-hosting more viable, since our availability is constrained by internet provider rather than power.
Yeah we did a similar thing. Same situation, spouse and I both work from home, and we got hit by a multiple day power outage due to a rare severe ice storm. So now I have an EV and a transfer switch so I can go for a week without power, and I have a Starlink upstream connection in standby mode that can be activated in minutes.
Of course that means we’ll not have another ice storm in my lifetime. My neighbors should thank me.
Well, it's an EV with a big inverter, not a generator, but I get your point. And I do periodically fire it up and run the house on it for a little while, just to exercise the connection and maintain my familiarity with it in case I need to use it late at night in the dark with an ice storm breaking all the trees around us.
Oh, I see! Genuinely curious -- what kind of EV has a battery to power a house for a week?
> maintain my familiarity with it in case I need to use it late at night in the dark with an ice storm breaking all the trees around us.
That's the way to do it. I usually did my trial runs during the day with light readily available but underestimated how much I needed to see what I am doing. Now there's a grounding plug and a flashlight in the "oh shit kit".
> what kind of EV has a battery to power a house for a week?
Assuming their heating, cooking and hot water is gas, a house doesn't actually consume that much. With a 50kWh battery you can draw just under 300W continuously for a week. I'd expect the average house to draw ~200W with lighting and a few electronics, with a lean towards the evenings for the lighting.
On paper the numbers look right, but a week off _50kWh_ EV battery feels off.
What follows is back of the napkin calculations, so please treat it as such and correct me if I am wrong.
1. Inverters are not 100% efficient. Let's assume 90%
2. Let's also assume that the user does not want to draw battery to 0 to not become stranded or have to do the "Honda generator in the trunk" trick. Extra 10%?
3. 300W continuous sounds a bit low even with gas appliances. Things like the fridge and furnace blower have spiky loads that push the daily average. Let's add 100W to the average load? I might be being too generous here, but I used 300W, not the 200W lower bound.
4. Vehicle side might need some consumption. If powering off the battery, it would probably need to cool the battery or keep some smarts on to make sure it does not drain or overheat? Genuinely not sure how to estimate this, let's neglect it for now.
Math is (50kw - 10%(inverter loss) - 10%(reserve)) / 0.4 = 100 (hours), ~ 4 days.
The above calculations assume a sane configuration (proper bidirectional wire, not suicide cord into 12v outlet). Quick skim of search for cars with bidirectional charging support for home shows batteries between ~40kWh(Leaf) to 250 kWh (Hummer).
So looks like one should be looking for ~80kWh battery, which actually most of the cars in the list have.
Again, very back of the napkin, would probably wanna add 20% margin of error.
Actually yes one thing I didn't consider in my calculation is the fridge (mostly because it's a spiky load that rarely comes on and I based it off my own apartment's instantaneous consumption at the time which was ~100W since the fridge compressor wasn't running).
Indeed with the fridge it pushes it a bit. But to address some of your other points:
> it would probably need to cool the battery
I'd expect if you're in a storm then you probably don't need any cooling - not to mention a 300W load is nothing for an EV battery compared to actually moving the vehicle. I'd expect some computers in the vehicle to be alive but that should be a ~10-20W draw.
On the other hand, my calculation assumes ~300W continuous. I expect the consumption to lean into the evenings due to the extra lighting, and drop off during other times.
But yes 80kWh might very well be what the OP has; I intentionally picked 50kWh as the lowest option I found on a "<major ev brand> battery kwh" search.
2025 was the year of LiFePo power packs for me and my family. Absolute game changers: 1000Wh of power with a multi-socket inverter and UPS-like failover. You lose capacity over a gas genny but the simplicity and lack of fumes adds back a lot of value. If it’s sunny you can also make your own fuel.
You’re right, it’s not much, but it is convenient and clean. A few lamps, USB charging, and a router/modem will use a few tens of watts and the big power pack will keep that going for eight hours.
For longer outages there is an outhouse with triple-redundant generators:
- Honda c. 2005
- Honda c. 1985
- Briggs & Stratton c. 1940
The “redundancy” here is that the first is to provide power in the event of a long power outage, and the other two are redundant museum pieces (which turn over!)
Generac 26kW Guardian, natural gas fueled, connected to a pair of automatic transfer switches. We have two electric meters due to having a ground source heat pump on its own meter.
During winter outages, do you stick to the heat pump or switch to a backup heat (e.g. furnace)?
I regrettably removed our old furnace/tank when installing the air source heat pump we have now (northeast), but that’s been my biggest concern power wise
This also makes self-hosting more viable, since our availability is constrained by internet provider rather than power.