New Ontario Utility Rates coming - good or bad for DIY Solar?

I have been watching to see what the Ontario Utility (Hydro-One) Rates will be,
Since the Inflation over the last while I wondered what would be coming down the line.
They surprised me, with a new set of rates that will be offered - customers can choose if they want the new deal I am told.
The new deal increases the On-peak rate, a few cents,
holds the mid-peak rate the same
and dramatically cuts the off-peak rate, but shortens it's hours from 12 hours to 8 hours per night.
On peak was 15.1 now going to 24.0 cents/kWh (and fewer hours will have this rate apply: 4-9 pm weekdays only)
Midpeak stays at 10.2cents/kWh (no change)
Off peak was 7.4 but now going to 2.4 cents/kWh (in USD this is 1.8 c/kWh)
{FYI: all these rates are for energy used, there is also a fixed 'delivery' cost added to hydro bills as well}

Anyone with batteries and an inverter can load-shift to literally pay 10% of the peak rate/ 25% of the midpeak rate.
They are specifically calling for EV owners to charge 11:00PM to 7:00AM to get this super low rate, and avoid adding extra load during the peak time of the day.
I wonder how this affects the incentive to move to Solar, these new rates are optional, you don't have to use this plan. But that 2.4C rate is only available if your in this plan.
I can see people building an entire system around load shifting and skip the PV all together.
For me it is great news for next winter, since my use of Utility power is mostly Nov - early January, and I already have off-peak only battery charging set up with my system. This new ultra low rate will cut 75% off of what I pay now for winter charging of batteries, and allow EV charging at night when PV is not able to provide enough energy.
Ultimately since it is optional, you can be sure those that opt-in are going to be planning on using that low low overnight rate, even electric resistance heating/heat pumps will be attractive at that price point.

OffGridForGood said:

Off peak was 7.4 but now going to 2.4 cents/kWh (in USD this is 1.8 c/kWh)

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Probably because you guys have 51% of energy from Nuclear. Can't shut it down at night so they are almost giving it away. If this rate applies during winter then you have super awesome deal for space heating. How much do remaining costs and taxes add up to?

The "Gottch" is they charge for "delivery" and a fixed charge per month (about $36) plus some kitchen sink items like regulation charges, and a fee that goes towards the deep earth repository for the nuclear waste. All told this adds a few cents per kWh on average. In the NorthWest all produced power is Hydro (water), Wind, bio-mass. Those Nukes are all in the south where the population is high, and the only water-generation is Niagara Falls.
The Ultra off peak rate is pretty exciting for EV charging potential, especially since my local cost for gasoline is high compared to other parts of N.America, but the electric is so low. I have two side by side properties, so I am thinking of applying for the Ultra off peak on just one, and keep the normal ToU rates on the other. Will have low cost charging for the EV (hope to be two of them one day).

Mixing nuclear and hydro is about the most symbiotic way to get power around. Your rates are very low on par with what we pay here.

Nuclear with Hydro with ponding, or pumped storage.

I believe all of Niagara generators are “run of the river”

Don’t know if Ontario took a Hydro Quebec approach to flooding out northern First Nation land.

OffGridForGood said:

The "Gottch" is they charge for "delivery" and a fixed charge per month (about $36) plus some kitchen sink items like regulation charges, and a fee that goes towards the deep earth repository for the nuclear waste. All told this adds a few cents per kWh on average. In the NorthWest all produced power is Hydro (water), Wind, bio-mass. Those Nukes are all in the south where the population is high, and the only water-generation is Niagara Falls.
The Ultra off peak rate is pretty exciting for EV charging potential, especially since my local cost for gasoline is high compared to other parts of N.America, but the electric is so low. I have two side by side properties, so I am thinking of applying for the Ultra off peak on just one, and keep the normal ToU rates on the other. Will have low cost charging for the EV (hope to be two of them one day).

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That's factually incorrect. There are many "small" scale hydro facilities scattered all over southern Ontario.

Bellwood lake (shand dam), lake Conestogo, Guelph. Hydroglen - is a stretch but Orillia is still Southern Ontario. Etc etc etc.

If you look at the super low overnight rate, plus daytime PV, it may take away a lot of the incetive to have batteries at all.
Winter storms and frequent power outages are my incentive for a large ESS system.

kennyb said:

That's factually incorrect. There are many "small" scale hydro facilities scattered all over southern Ontario.

Bellwood lake (shand dam), lake Conestogo, Guelph. Hydroglen - is a stretch but Orillia is still Southern Ontario. Etc etc etc.

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I think each of those dams primary concern is for flood control, I don’t believe the operate toward grid demand but more of water flow.

All the active hydrogeneration stations are listed on Hydro Ones' website, for anyone interested.

I am thinking about doing the switch to the ULO rate, but adding a home battery.

Without Battery storage, it comes out in the wash. Like maybe $3 difference between the TOU and ULO rates.

That 2.8¢/kWh rate is a savings of about 6¢ over the old non offpeak rates.
However, they boosted the new Peak Rate by 16-19¢/kWh to pay for it.

My wife likes to run the dishwasher / laundry after 7pm to get the current cheap rate of 8.7c/kWh. There is no way she is waiting to 11pm to do the laundry (dryer). Dishes can be set on a timer to start after 11pm.

I have been pondering it,
Batteries for on-peak and mid-peak
charge the EV off peak (ULO rate)
Poor solar months Nov-Jan charge up the batteries on the ULO rate.

We mostly only use off peak right now, but still pay the regular off-peak 8.4 cent rate instead of that new 2.8 cents they are offering.
It takes a lot of battery bank to run three dryer loads, keep the HWT running, and run my business next door, especially since next up I will be adding in the electric oven.

I'm currently trying to decipher the ESA code for ESS in Ontario.... some of it doesn't make sense....

field built battery can only be <1kWh capacity? what?

I would also have to put my electrical panel and inverter etc in a room with 5/8" drywall to make it 1hr fire proof.... I'm going to have to call someone and figure out if I can DIY battery in Ontario and pass inspection.

petee_c said:

I'm currently trying to decipher the ESA code for ESS in Ontario.... some of it doesn't make sense....

field built battery can only be <1kWh capacity? what?

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Yup thats what it says.
if you build your own, you are not going to getting it inspected.
if you buy factory made, be sure they have the ULC stickers. oh and the rules say you can't put factory packs in a basement (they worry about flooding) you can't put them in any part of the house near bedrooms (ie worried about fires)
Generally a lot of safety rules.

petee_c said:

I would also have to put my electrical panel and inverter etc in a room with 5/8" drywall to make it 1hr fire proof.... I'm going to have to call someone and figure out if I can DIY battery in Ontario and pass inspection.

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not if you build bigger than a 1kWh.
Now you know why I am not interested in grid tie, not building any of my solar in/on/near the house.
The really frustrating part was trying to get a copy of the Canadian Electrical Code - without paying $300 just to be able to read it. Clearly they are not interested in safety, or the code would be available for any home owner to read any time we want.

Edit: I was able to get a scanned copy of the 2021 CEC. Seems they have opened up some of the rules since the previous version. generally looks like 40kWh limit (with some exceptions) for the ESS two racks of 20kWh set 1-meter apart in a garage, but they appear to still be based upon the packs being UL 9540 compliant.

OffGridForGood said:

Yup thats what it says.
if you build your own, you are not going to getting it inspected.
if you buy factory made, be sure they have the ULC stickers. oh and the rules say you can't put factory packs in a basement (they worry about flooding) you can't put them in any part of the house near bedrooms (ie worried about fires)
Generally a lot of safety rules.


not if you build bigger than a 1kWh.
Now you know why I am not interested in grid tie, not building any of my solar in/on/near the house.
The really frustrating part was trying to get a copy of the Canadian Electrical Code - without paying $300 just to be able to read it. Clearly they are not interested in safety, or the code would be available for any home owner to read any time we want.

Edit: I was able to get a scanned copy of the 2021 CEC. Seems they have opened up some of the rules since the previous version. generally looks like 40kWh limit (with some exceptions) for the ESS two racks of 20kWh set 1-meter apart in a garage, but they appear to still be based upon the packs being UL 9540 compliant.

Click to expand...

Just get the 2021 knights CEC book. Its like $30 and has an excellent appendix.

Nothing bigger than 1kwh in a dwelling unit...Unless and it's up to the inspector, packs are listed as for indoor residential use and are in a 1hr fire room. There is a bulletin on the ESA site detailing this "exception".

Packs need to be 1M apart unless otherwise indicated. Must be ul9450 complaint (ie listed with the inverter). Maximum of 40kwh in an attached structure and 80kwh in a detached structure.

I've had extensive conversations with my local inspector about this and how Ev's are ok. His hands are tied, but he agrees there will be a revision or a change in the next code

Have fun.

Looks good for a battery system to load shift. As far as solar alone it would depend on what is paid for exporting to the grid.

OffGridForGood said:

Yup thats what it says.
if you build your own, you are not going to getting it inspected.
if you buy factory made, be sure they have the ULC stickers. oh and the rules say you can't put factory packs in a basement (they worry about flooding) you can't put them in any part of the house near bedrooms (ie worried about fires)
Generally a lot of safety rules.


not if you build bigger than a 1kWh.
Now you know why I am not interested in grid tie, not building any of my solar in/on/near the house.
The really frustrating part was trying to get a copy of the Canadian Electrical Code - without paying $300 just to be able to read it. Clearly they are not interested in safety, or the code would be available for any home owner to read any time we want.

Edit: I was able to get a scanned copy of the 2021 CEC. Seems they have opened up some of the rules since the previous version. generally looks like 40kWh limit (with some exceptions) for the ESS two racks of 20kWh set 1-meter apart in a garage, but they appear to still be based upon the packs being UL 9540 compliant.

Click to expand...

Got to searching as I'm curious about this.

From here

The Canadian approval standard, ANSI/CAN/UL 9540, permits only ESS designed and marked as “Suitable For Use in Residential Dwelling Units Where Permitted ” in the living or habitable areas of a dwelling unit

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There is nothing in the product standards that prohibits ESS not marked as “Suitable For Use in Residential Dwelling Units Where Permitted ” to be installed in other than the living or habitable areas of a dwelling unit. UL 9540 allows certified ESS that meet the regular tests in the standard to be installed in non-living or non-habitable areas of a dwelling unit (e.g. utility closets, attached garages or storage spaces). This is evident in Table E.1 “Residential use ESS” where it is further clarified by showing the capacity limitations and separation requirements of ESS permitted in dwelling units.

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So it looks like the minimum is UL 9540, and it can be installed in a non-habitable location even if it's not marked as "Suitable For Use in Residential Dwelling Units Where Permitted"

Additional interesting tidbits:

d) Individual ESS capacity does not exceed 20 kWh;
e) Multiple ESS aggregate capacity does not exceed 40 kWh;

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It looks like they're nice enough to "allow" up to 80kWh but only in a detached structure/garage.

Deviation may be possible with approval




Certainly a lot of complications for anyone wishing to do this sort of thing with all the proper approvals, etc.

Let's hope they do change things a bit so it's not so restrictive. Especially the capacity aspect of it.

Yeah, I feel they wrote the rules based on concerns for some of the lithium-ion chemistries, before LFP was common in the market.
I have a metal building away from my residence so that part worked for me, but I was damned if I would let them dictate factory only UL 9540 and I built my own packs anyway. There is another exception for 'mult-residential' I may use that too.
Anyway like you say, they will likely catch up on the next code update.

I've got a call in to the solarpowerstore here in Canada... they're going to price out a small 5kW solar system for me (hopefully get the grant), and also a small maybe 120V inverter/small battery backup (14kWh I believe is the smallest UL9541 available ATM), and see what that costs.

I had started the Greener Homes Loan application back in March 2022, hopefully it's still open. I have reached out to them as well to inquire. If that is the case, I can get it covered by the loan...

In the process of looking at a heatpump laundry dryer, or a 110V All-in-one washer/dryer. GE has one in Canada. Can't find the LG or Samsung offerings yet up here.

Alternatively, I may MacGyver a system to cover a few of the evening loads on a 'portable' system. (Essentially removing 4-5 circuits from the breaker panel and switching them over to the inverter.

24V 280Ah DIY battery & BMS (6.7kWH)
3000W 120V Pure Sine Inverter (Amazon)
24V battery charger.

The battery and BMS are fairly straight forward. I would need a battery charger that can remember settings when unplugged/unpowered, or defaults to the proper settings when plugged in. Hoping to run the charger on a wall timer to capture the ULO rates. I figure if I can capture 4-5kWh of peak energy use, 81% efficiency in charging and inverting, I should save $245/yr on my peak rates. Assuming I can build it for under $1800CDN, payback would be 7 yrs.

The automated charging may not be possible, and if that's the case.... back to the drawing board.

kennyb said:

Just get the 2021 knights CEC book. Its like $30 and has an excellent appendix.

Click to expand...

Looked this up - $52.00 plus tax plus ship on Indigo.
Lot better than $300.
I got a free scanned digital copy of the actual 2021 CEC code, but it's not easily searched.
The code is a public safety document, it should be free to anyone that would like to take the time to read it.

petee_c said:

The automated charging may not be possible, and if that's the case.... back to the drawing board.

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Leave the charger plugged in, and interrupt the connection to the system with a relay running on a Geeni plug. programable and you don't have to worry about losing the charger settings.

OffGridForGood said:

Leave the charger plugged in, and interrupt the connection to the system with a relay running on a Geeni plug. programable and you don't have to worry about losing the charger settings.

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That was an option I was thinking of... Put the relay/solenoid on one side of the leads between the charger and battery.... That would interupt the charging... <-- I think that's what you're suggesting.

Yes, use the smart plug between - gives you easy controls and programing. heck you can turn it on and off anywhere with internet connection with your phone!

petee_c said:

I've got a call in to the solarpowerstore here in Canada... they're going to price out a small 5kW solar system for me (hopefully get the grant), and also a small maybe 120V inverter/small battery backup (14kWh I believe is the smallest UL9541 available ATM), and see what that costs.

I had started the Greener Homes Loan application back in March 2022, hopefully it's still open. I have reached out to them as well to inquire. If that is the case, I can get it covered by the loan...

In the process of looking at a heatpump laundry dryer, or a 110V All-in-one washer/dryer. GE has one in Canada. Can't find the LG or Samsung offerings yet up here.

Alternatively, I may MacGyver a system to cover a few of the evening loads on a 'portable' system. (Essentially removing 4-5 circuits from the breaker panel and switching them over to the inverter.

24V 280Ah DIY battery & BMS (6.7kWH)
3000W 120V Pure Sine Inverter (Amazon)
24V battery charger.

The battery and BMS are fairly straight forward. I would need a battery charger that can remember settings when unplugged/unpowered, or defaults to the proper settings when plugged in. Hoping to run the charger on a wall timer to capture the ULO rates. I figure if I can capture 4-5kWh of peak energy use, 81% efficiency in charging and inverting, I should save $245/yr on my peak rates. Assuming I can build it for under $1800CDN, payback would be 7 yrs.

The automated charging may not be possible, and if that's the case.... back to the drawing board.

Click to expand...

Battery and inverter must be a matched pair to be ul9450.

The solar power stores battery is a rebadged gsl battery. The gsl battery is ONLY tested with the lux 12k. Even thought the eg4 is identical the ul9450 cert is only good for the lux12k.

OffGridForGood said:

If you look at the super low overnight rate, plus daytime PV, it may take away a lot of the incetive to have batteries at all.
Winter storms and frequent power outages are my incentive for a large ESS system.

Click to expand...

Resiliency is the big reason togo with batteries. I switched over to the ultra-low rate last month. Charging my car is about free now. Solar panels recently installed, so don't draw from the grid during the day. Batteries smooth out the bumps...

petee_c said:

I'm currently trying to decipher the ESA code for ESS in Ontario.... some of it doesn't make sense....

field built battery can only be <1kWh capacity? what?

I would also have to put my electrical panel and inverter etc in a room with 5/8" drywall to make it 1hr fire proof.... I'm going to have to call someone and figure out if I can DIY battery in Ontario and pass inspection.

Click to expand...

Let me know what you find out

I have been following along on a CEC electrical forum, they are chatting about a new version coming 'soon' to the CEC, since many of the current requirements were drafted during a time before LFP was the common battery in the market.
Meanwhile per the Canadian Electrical Code a field built battery is supposed to be "less than 1kWh" capacity. (I decided innovation was not to be stiffled with regulation and did my own 'experimental' battery development - there actually is an exception for this btw)
My understanding is - no DIY battery will pass an inspection in Ontario/Canada under the existing code requirements.