Friday, November 22, 2024

Success story: using a battery + an electric vehicle for an extended power outage

With the historic wind storm that hit Washington earlier this week -- knocking out power to something like half-a-million customers! -- I bet there are a lot of people thinking "I should get a generator". I want to plant the seed of another idea: that a great alternative is an electric vehicle with V2L (Vehicle-to-Load; which the Kia EV6 & EV9 have, among others), plus [ideally] a whole-house battery.

A low-key solution that involves an EV and nothing else -- and what I ended up doing for my parents -- is just running an extension cord from the vehicle into the home, and plugging in a select few things (a fridge, a floor lamp, and a microwave -- just being sure to alternate the microwave and fridge usage, to avoid exceeding max wattage). If you're OK with "roughing it" or live in a dense neighborhood and can expect to get power back on within a day, this is totally survivable.


But for our home, we bought a whole-house battery (in our case, an EcoFlow Delta Pro Ultra, but there is a similar offering by Anker and others): and WOW, it's been a game changer! The device is a giant battery + inverter. In addition to regular 120v plugs, it has a 240v 30A output just like a regular generator, letting us plug it into a transfer switch and thus connect it to our home's electrical panel. The EcoFlow allowed us to keep most of our circuits running: fridge, microwave, lights, various electronics, etc; we could even run our water heater, though we kept that to a minimum (but boy, was the hot shower nice!). When needed (e.g., for our water pump or the water heater), it could output a huge burst of power -- way higher than what our EV's 120v 15A circuit could have. But the best thing was that we could replenish the EcoFlow's power from our electric vehicle, since -- except during bursts -- our baseline electric needs were on average significantly smaller than what the EV could provide.

The EcoFlow Delta Pro Ultra, connecting to our home via a 240V plug, and being simultaneously charged from the EV via a standard120V outlet. This specific moment is when our booster pump is running, hence it's outputting nearly 3000W. During regular non-burst moments, our electric needs were ~500W per hour.

By itself, with liberal usage of all the circuits we wanted, the fully-charged EcoFlow could power our home for 8-10 hours. So with the car (whose battery capacity is ~13x of the EcoFlow) feeding it, it could easily give us 4+ days. Moreover, because the EcoFlow is separate from the car, I knew I could leave it powering the home while I myself left to run some errands and help my parents; knowing that, once I get back, I can quickly replenish it!

The EV charging the EcoFlow. Note that the actual amount of time remaining would be significantly higher than the stated 16 hours, since -- once the EcoFlow is charged up -- the car would need to only "trickle"-charge it.

You may ask: what happens a few days later, once the EV capacity is mostly eaten up? Well, the electric vehicle is a giant battery pack on wheels! To test the concept, and because I had used up some of the EV's capacity by driving, I took a trip to the charging station last night. The Electrify America app showed me that the nearest station (Redmond Ridge) was operational, just like I expected: even though our own rural home was without power, of course the more densely-populated areas and businesses were restored. I drove there around 9pm in the evening; had no waiting time; plugged the EV into a DC fast charger; went inside the adjacent QFC to get sushi; got back into the car to eat it; and was amazed to see that even in those 15-20 minutes, the car had gone from 40% to 80%! Just like that, we would be good to go for a few more days! The process was so easy that I took another celebratory hot shower, feeling like I could afford the extravagance, since bringing home a "full tank" of electricity was really a non-issue.

Charging the EV9 at an ElectrifyAmerica location, to bring back home a "full tank" of electricity.

Compared to our previous setup -- of dragging out a portable generator, trying to get the dang thing to start, choosing only the truly critical circuits (both because we wanted to use as little propane as possible, and because I didn't want to damage lights and electronics with fluctuating power), and hearing and smelling it outside -- my new setup felt revolutionary. I realize that it's not a true apples-to-apples comparison: there are of course excellent [and expensive] whole-house generators that DO provide consistent power and have a giant propane tank to fuel them. BUT, I didn't want to spend some $15k on an excellent system that I only use a couple times per year, and that is fundamentally not environmentally friendly. Whereas with my system, I was able to spend just a fraction of the cost on the whole-house battery (~$5k for the EcoFlow Delta Pro Ultra), and invest the rest into a shiny new electric vehicle that I use and enjoy every day!

I cannot overemphasize how happy I am with this system; and how surprised I am that I haven't seen others do this. It worked flawlessly for us for two days, until our grid power was restored. If folks have any questions, I'm happy to answer them. I have no affiliation with either Kia or EcoFlow; I just am thrilled to see my setup work, and imagine that others could benefit from realizing that something like this is possible. 

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P.S.: It turns out that with EcoFlow, since I'm an existing owner, there’s a referral program whereby you could could get a 5% discount via this "refer a friend" link (though not sure if it stacks on top of the Black Friday deals): https://www.ecoflow.com/us/referral-rewards?inviteCode=AXCXRJAF

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