Grid tied with battery backup code changes

[Alain Amyotte]

I am in the first stages of designing my ground mount DIY solar system. I live in Ontario and have made the application to Hydro One for net metering approval.
In the meantime I am looking up pricing for a Solaredge grid tie system with battery backup and night usage. One place I called mentioned that with the new code changes to energy storage the Inspectors may not be on board with new systems with battery storage.
Has anyone come across this?

[Rob Beckers]

Hi Alain,

The inspectors are fine with energy storage systems (as the new category is called in code), as long as you follow all the new code rules for it. I'm not at work right now, and can't grab the code book; there are quite a few (new) rules surrounding these systems (one is you can't place them inside a house, though I'd like to check if inside the garage is possible).

Inspectors largely don't know yet how to treat energy storage systems, and in a larger context just large (lithium-ion) battery banks. The question being when something stops being just a battery bank, and becomes an energy storage system. I had a chat with an inspector just a couple of weeks ago, and he had no clue. He was going on a course a week later, and I need to follow up with him to see if more info is available now.

There are no rules against energy storage systems, if you want to go that route that's fine, you just have to follow the (code) requirements. Best advise is to get together with the inspector before you build (or even buy) anything, go over the plans, and let the inspector tell you if they are on board, or if they want to see specific changes. That way nobody gets blind-sided.

-RoB-

[Alain Amyotte]

Hello Rob. Thank you for the information. I plan to put the battery in my attached workshop that is heated to 10C in the winter. I will look up if that would be acceptable. Good idea about having a chat with the inspector prior to buying anything. I hope that the inspector is willing to have that conversation. When I built my house he didn't seem open to any dialog.

[Dan Lavoie]

Are these the new addition to the code that you are referring to?

Bulletin 64-7-1, Installation and Approval of Energy Storage Systems, Rules 2-024, 64-900, 84-002 and 84-022, Issued May 2022
https://esasafe.com/assets/files/esasafe/pdf/Electrical_Safety_Products/Bulletins/64-07-1.pdf

Bulletin 64-8-0, Battery based ESS in residential occupancies, Rule 64-918, Issued May 2022
https://esasafe.com/assets/files/esasafe/pdf/Electrical_Safety_Products/Bulletins/64-08-0.pdf

[Rob Beckers]

Hi Dan,

The main section is in the regular Ontario electrical code book, the current one is the 28th edition (2021 code) that came into effect in May of 2022. Sections 64-900 through 64-928 are completely new, and deal with Energy Storage Systems (ESS). Note that this comes in addition to section 64-800 that was (and still is) about Battery Banks. I wasn't aware of the two bulletins you mention, looks like those are an explanation (and in addition) of the more practical aspects of the code book, as the ESA often does when there's confusion.

I get the intend of the new ESS category; it is to capture such things as the Tesla Powerwall and similar devices that are popping up everywhere, and are meant to enable load displacement, load shedding, and possibly some off-grid ability for when the grid goes down. What we've heard from installers and customers since May of last year is that inspectors have by and large taken the point of view that ANY lithium-ion battery bank is automatically an ESS. Even if it's just a battery bank for an off-grid system (note the definition of ESS actually says it's a system that works in combination with the grid). That is very unfortunate, as it makes the use of lithium-ion battery banks in general very much more difficult.

Section 900 of the code book has much to say about the location and size of the battery bank: You can't install batteries in a basement ("below grade" as it is described), unless it is in an "electrical equipment vault" (not sure how that's defined). The limit for any battery bank inside a "dwelling" (ie. 'house') is 1 kWh, which is pitiful for an off-grid system. Code does allow installation in an attached garage, with a limit of 20 kWh for the bank, or 40 kWh for two banks as long as both are separated by 1m or more. For a detached garage or outbuilding you can go to 80 kWh (with a 20 kWh per bank limit, and 1m spacing still in effect). The battery bank has to be at least 3 meters away from any door or egress means.

That's the main part in terms of limitations. As mentioned, this seems to be applied to ANY lithium-ion battery bank. Luckily inspectors will still see a lead-acid bank as a regular "Battery Bank" without dipping into the ESS rules. For lithium you're $hi% out of luck though.

In case you are outside of Ontario: The Canadian Electrical Code (CEC) has the same rules, and most provinces follow the CEC, though they may be on an older version still. The USA has the same in their NEC.

-RoB-

[Ralph Day]

Thanks for clarification Rob. I think I'll be waiting for sodium ion batteries to come on line...unless they'll be treated in a similar fashion.
I can understand about not in a dwelling after reading about the gasses that can be found in Lion smoke in a fire.

Ralph

[Rob Beckers]

You mean molten sodium Ralph? That REALLY sounds dangerous! :sick:

The thing with lithium-ion batteries is that the rules are treating all the lithium chemistries the same. The horror stories all involve lithium-cobalt (or derived) batteries, they are used in laptops, cell phones etc., and have a very bad thermal-runaway issue. Once those batteries go, they don't stop, and it involves much flame & smoke. The chemistry generally used for deep-cycle (larger) lithium batteries is lithium-iron, and that is much more stable. Of course, any time you store large amounts of energy there is the potential for disaster, but that exists for lead-acid batteries too.

While I agree that the fumes coming from a burning lithium battery are nasty, that's not really any different from the fumes of all your other items in the house when they are on fire. Lots of PVC around, and that makes hydrogen chloride and carbon monoxide when it burns. It'll kill you just as fast!

-RoB-

[Ralph Day]

Hi Rob
The sodium ion batteries are being made in one of the big Chinese Li-on battery factories. They don't even have to change production methods that much. Use Na and aluminum instead of Li and copper from what I understand.

Might be a long wait.

Ralph

[Rob Beckers]

Thanks for pointing that out Ralph!
Just did some reading-up on sodium batteries. They do indeed look promising.

-RoB-

[Ralph Day]

If I know my trusted re gear supplier (you) you'll be my go to place for battery replacement...eventually. My s550's are doing well, but I'm glad I have utility power. I can off-grid in the summer, but 8 month s of the year that's not comfortably possible.
I always think about more pv, but then think about all the work and materials that bring their energy to the house...wire, trenching, racking, controlling etc. And Janet is very antsy any time I get close to the house with a hammer drill!