Unpermitted DIY TOU arbitrage in CA

[Clipper81]

One question… Is DIY TOU arbitrage legal in CA?

I have EV-TOU because of my EV pursuits; been charging my cars from 12>6AM for the last two years.

I am an EV conversion guy, made myself a battery wall from regular old prismatic LiFeP04 cells taken out of EV's at 80% of original capacity. Virtually free battery wall, 24KWH. 3P20S connected with 4x7x1/4" aluminum plates and adequately sized copper bus bars. (Photo attached.) Plenty enough juice to cover my house usage, excluding car charging, which happens from midnight to 6 AM anyway, and does not go through the inverter.

Very simple system, actually. No solar, no back up gen. Just batteries, an inverter and an external charger on a timer.

I am quite competent to design and install this system to code...and I have a licensed electrician friend to double check my work for any code violations, and provide certification to my insurance company if necessary.

Skipping all the unnecessary (for this question) design details:

110/240VAC: Grid Panel>Inverter>House Panel>House Loads (Photo attached)

68VDC: Batteries>Inverter (Photo attached)

240VAC/68VDC:
Grid Panel>Timer>Charger>Batteries

Cost: 2400 bucks for a brand-new Outback inverter, a few hundred more for a brand-new Intermatic timer and used Elcon charger (removed from a car and reprogrammed,) new copper wire and conduit, breakers and breaker panel, etc. I did the math and will save about half of my previously $225-250/month bill. The payback on that is pretty short... about 18-24 months.

In the EV world, you do pretty much what you want, without any oversight or enforcement. The only governing laws are those of physics and engineering. No politics, no goobermint inspectors or enforcers.

But house electrical systems have codes, oversight, enforcement and insurance implications. Not to mention nosy neighbors.

Is there anything unlawful about doing this myself, or using TOU to charge house batteries from midnight to six?

Do I have to get permits for any of this? I'm not interested in any gooberment incentives or "benefits," just in saving half my bill. I will interface with them when absolutely necessary, to get my TOU rates, for example. But in general, the further away you keep me from any gummint or investigative or legal agencies, judges, lawyers, corporations or pissed off power companies, or anybody else with the power to make me do something that doesn't make sense, the happier I stay.

 

[zanydroid]

You'll need to check if IRC as amended by California still allows recycled EV batteries to be installed in an ESS. If it does not then this would not be a legal installation. ESS is aggressively covered by code (with more sections added to California code every cycle), so I presume that means you will need to get a permit for this. But perhaps your AHJ does not care (the ones next in adjacent cities in my county all care about ESS0.

As long as you do not export to grid (sounds like you are not on a NEM plan) nor operate in parallel with grid (which your line diagram appears to achieve) you avoid a lot of regulation.

If using LFP chemistry and don't care about permits, why are you going with separates instead of a high-volume AIO? You can get 6kW or 10kW inverter-charger for $1500. Originally I thought the separates was to get more safety factor with NMC but then I re-read your post.

 

[DIYrich]

You can't "arbitrage" if you can't sell back (buy low, sell high). You can demand shift (buy low). If you meet all code requirements (UL 9540), you can probably get the permits to DIY. To "sell back" you would then need PTO from the Utility.

 

[Clipper81]

You can't "arbitrage" if you can't sell back (buy low, sell high). You can demand shift (buy low). If you meet all code requirements (UL 9540), you can probably get the permits to DIY. To "sell back" you would then need PTO from the Utility.

My bad, I'm still getting used to the home installation "lingo."

>> You'll need to check if IRC as amended by California still allows recycled EV batteries to be installed in an ESS. If it does not then this would not be a legal installation.

Speaking of the lingo, I also find it interesting that you called them "recycled" batteries.

I bought them new, for use in an EV. I know people buy these same batteries from China for the sole purpose of home installation…why would authorities care what reduced their capacity the first 20%?

In other words, they wouldn't make me remove and replace them from my home installation at 80% capacity, if they had originally been installed in my home…but since the first 20% capacity was used up by an EV, suddenly they care where the cells came from, and want to exercise their power and jurisdiction over me?

I know it's convoluted semantics, with a little politics thrown in…but… Do you understand my point?

From my perspective, I just repurposed them. To me, "recycling" them is when they won't hold a useful charge anymore. That's when you send them off for recycling...you disassemble them for their elemental components; the lithium, aluminum, copper and other metals inside, and the rare earths and plastic and whatever else is in there.

But yeah, I can see that if I had bought them from some other EV guy, they would be considered "recycled."

Emblematic of my general observations about home installations versus EV installations... different set of rules, and even a different lingo. I had better watch my step when dealing with self-aggrandized "authorities."

Does the power company have a problem with me "demand shifting?" Will they somehow take notice of the suddenly different usage patterns? Will I get a nastygram from PG&E, wanting one of THEIR "authorities" to inspect my "installation," even though it's completely within the confines of my own home, and not "grid-tied" at all?