18 points luu 20 hours ago 11 comments

frereubu 46 minutes ago | parent

Wouldn't the charge / discharge cycles reduce the life of the car battery? I presume the same is true of in-home batteries, but although an in-home battery is an extra capital expense, I imagine the replacement cost of in-home batteries is quite a bit lower, isn't it? Would be interested to know more about the medium-to-long term economics of this.

deathanatos 32 minutes ago | parent

> Wouldn't the charge / discharge cycles reduce the life of the car battery?

While I'd presume the answer here is "yes", I'd also presume we're talking like a fraction of the vehicle's lifetime charge cycles. Like, (generously/conservatively) 20 to 40 cycles total over the life of the vehicle, no? How often would you estimate your power going out?

jauntywundrkind 24 minutes ago | parent

I don't think that wear would be worse than driving around. Unless you go out, recharge, and come back, by definition you only have a single charge single cycle to give.

bob1029 46 minutes ago | parent

My biggest problem with batteries for grid outages is that the only outages I am actually concerned with would drain them to zero before the outage is resolved. For short term, smaller/portable batteries are fantastic at bridging a few hours. Plug the wifi & fridge in and you can sometimes go for 2-3 days.

I am not aware of any economically feasible way to run my 5+ ton HVAC system full-time on batteries after a hurricane just reset all the infrastructure, and you do need to run it full time because of the insane humidity and latent heat that follows a tropical system. Doing the math, I'd need something approaching 800kWh of storage to ride through this kind of event (7+ days). This is approaching half a million dollars in batteries. I can install an extremely nice 1800 RPM generator for ~15% of this cost, which would also include a year's worth of propane buried on the property.

I think a simple generator on an ATS remains undefeated from an engineering perspective. If you have an air cooled unit, the maintenance is not much more complicated than with a lawnmower. You just have one extra spark plug to deal with, and sometimes the oil pressure sensor needs replacing. I can get my stubborn Honda generator to start with all kinds of weird tricks. If my Ecoflow battery starts to act weird, I have very little recourse by comparison.

vlovich123 25 minutes ago | parent

Oil generators have an “artificially” low price because there’s a lot of demand for oil for other things. If the other sources of demand go away, the price may become unfavorable even if gas generators make a lot more sense from a redundancy perspective.

maxerickson 20 minutes ago | parent

The future cost would likely be based on chemical synthesis.

dlubarov 22 minutes ago | parent

Yeah it's hard for batteries alone to compete with generators, unless we put a lot of weight on things like noise, or are just focused on small loads like fridges.

I think the more interesting comparison is generators vs solar, though it depends on the local weather etc.

DenisM 37 minutes ago | parent

> The only way I can see to do this today is with Tesla Powershare + Cybertruck, which says "If the system includes a UL 1741-listed solar system

Since this was posted Tesla rolled out PowerShare to recent ModelY and some other cars. Not sure about solar recharge though. Where I live storms come in winter and I have natgas so most of the power will go to fridges and electronics, which will hopefully last long enough.

WarmWash 30 minutes ago | parent

You can do it with an F150 lightning if you have the 10kW inverter. Rather than use the charge port and the official charger, you use the 30A 240V plug in the bed to power your panel. You can charge the truck while using this too.

declan_roberts 22 minutes ago | parent

One of the problems with companies like GM is that they still see this as a premium feature and require their hardware (not just a charger). Tesla requires not only their chargers but also their inverters and cars.

What is missing is a spec that inverters and cars and chargers can all follow, then we will see mass adoption.

cmrdporcupine 13 minutes ago | parent

CHAdeMO had that spec, but of course is obsoleted now.

If I understand things correctly tho many of the V2L solutions just work with pretty much any car that does CCS, regardless of whether the manufacturer officially supports this or not. My Polestar2 for example doesn't official have any kind of V2H/V2L option but I've heard of many success stories.