Load Shifting in North America (specifically Canada)

[petee_c]

Anyone here do Load Shifting here? Or is there a forum you might recommend to talk / learn about this?

We have a Ultra-Low Overnight (ULO) rate of 2.8¢/kWh in Ontario. It runs from 11pm to 7am. I want to take advantage of it, as we have moved to EV's for our daily cars. We've had 1 EV since March 2023, and just added a 2nd one this week. I figure between the 2 EV's we'll charge about 350-500kWh/ month. This would be super cheap since I usually plug in just before bed. The energy overnight is mostly nuclear and hydroelectric.

To balance the cost out, the utility has created a Peak Usage rate of 28.6¢/kWh from 4pm-9pm M-F. It looks like we use between 8-10kWh/day during this time slot.

I want to transfer that 8-10kWh of energy usage to a battery, and then charge the battery ovenright during the ULO period. Energy use during this time is electric range/oven for dinner prep on most nights, as well as some loads through the dryer. - dryer isn't used every night. Dishwasher can be set on a timer to start after 11pm.

I have reached out to Cdn Victron dealer by email last week, but haven't heard back. I've watched a bunch of videos on the 6000XP inverter thinking I might be able to use that for my needs. So many things to learn.

- DIY battery and 48V BMS. Do they make BMS's that talk to inverters like the Victron or 6000XP?

- Grid power as the generator? Looks like there is a signal from the 6000xp that can turn on a generator? Is their a solenoid like device that I can use to turn on the grid that the inverter can control? - my feeling is that enabling a generator won't help my load shifting goal, as I believe the manual for the 6000XP says that the device will use the gen power and bypass the battery power, and not supplement the battery power.

- Grid Power as Grid Power - see above scenario( which likely doesn't work as I want it to)

- there is also a (MapleLeaf) 6500EX-48V that has passed CSA. I may look at that as well, but I would need 2 of them to get 240v split phase.

- I'm probably going to have to move the majority of these Peak Usage Items to a subpanel and hopefully capture 90%+ of the energy used during this time period. see list below

• electric stove
• kitchen receptacles /lights. Microwave circuit. I believe the Fridge was wired onto it's own circuit. (3-4 breakers)
• dining room lights - there is a small aquarium in there with a 100w heater on a thermostat, 20W of lighting, 20W for filter
• 'family room' lights/receptacles - TV that wife uses, Aquarium with 65Watts of Lighting, 300W heater, 20W filter. home PC is in there too; as well as some Internet stuff
• basement receptacles - extra fridge and upright freezer are there, as well as my gaming PC, and old PC running home network storage - likely 2 separate breakers down there will need to be in the subpanel
• dryer circuit - will train wife to not run dryer while dinner is on. She doesn't want to wait to 11pm though to run the dryer if so needed.
• HVAC? - we have a HE NG furnace with a modulatign DC motor. Not sure if it draws much juice...
• 5 stage modulating AC - House is on AC from late May - early September

If successful, and we switch to this ULO rate, we should save about $90-100/month off our electric bill, as well as no more trips to the gas station for the daily drivers.

There is a possiblity of adding a small (5kW) solar array to this setup as well. I would split it between a East and West Arrays, as we have some shading on parts of our southern roof. This may provide us with the needs for most of our house from April - September except for EV charging... This would up our savings to $100-150? maybe during the summer months.

Budget:
$5K Cdn ( $3750 USD) for the DIY 28kWh battery build / BMS / busbars
$5K Cdn ($3750 USD) for electronics (inverter)

If I can keep it under $10K for the home battery setup, Payback should be 8-9 yrs not counting inflation...

Not sure if adding solar will generate enough to make that payback any shorter.

 

[AntronX]

At $2.8c/kWh (Canadian $ ?) it may not make sense to get solar panels after you include all the costs to install them. Battery cell cost should be in $4c/kWh range if they last 3650 cycles and 10 years. Load shifting using DIY batery makes great financial sense in your case.

 

[1201]

Good news is you don't have any major surge loads.

Bad news is your electric dryer probably uses 6kw just by itself. It'll max out that 6000xp fast.

Are you sure you only use 8-10kwh during this time period? Even in the summer with ac use?

 

[zanydroid]

Check out the dryer thread. You can game out how much it is worth attempting a heatpump dryer or combo. Those need way less power. But take longer to run.

 

[petee_c]

Good news is you don't have any major surge loads.

Bad news is your electric dryer probably uses 6kw just by itself. It'll max out that 6000xp fast.

Are you sure you only use 8-10kwh during this time period? Even in the summer with ac use?

the 8-10kWh is a mid December work week (M-F)

July 10-14th we used 61kWh during that 5 day stretch in Peak Time according to the bill calculator from the utility. So just over 12kWh /day in the summer. Of course, in the Summer, we typically use the electric stove less, and the grill/bbq more. Looking on my car app, there was no EV charging during the peak period so that was all house loads.

I C U're in Texas... Our AC load isn't as high as yours. We set our house to 73-74F in the summer. Daytime highs might be 85F but more closer to 80F, Evening lows are probably 65-70Fon a really warm week. We do have humidity though.

I guess we could start using the dryer on the low heat setting for less draw, or look at the heat pump dryers.

attached is the graphic for July 10-14th if we had switched to the ULO rate plan (prices were cheaper last year)

Ideally, if we could run the big loads on battery from 4pm-11pm on a 28kWh battery, that would be ideal... concentrating on saving the most money during the peak times, and spilling over the extra battery capacity for some of the midpeak times, while having the DoD less than 70%

Solar may work, if we can get a grant to offset some of the costs, but it's hard to beat the current 2.8¢/kWh overnight price...

Yes in Cdn Pesos.

 

[DIYrich]

The difference between Peak and off-peak rates is 28.6-2.80, or 25.8 cents per kWh.

You said you used 10kWh/day during peak, so that is $2.58/day if you can shift peak consumption to non-peak using batteries. That is $77.40/mo (30 day month). You said you expect to save $90-100/mo. At $100/mo, that would require shifting 13kWh per day. However, batteries do not have 100% round-trip efficiency. Assuming 90% efficiency, shifting 13kWh/day would save $90/mo.

DIY a 14kWh battery using LF304 cells is about $2,500. The EG4 PowerPro is currently $3,800 USD.

To do time shifting, I would go with the Eg4 18kPV currently at $5,199 USD

With time shifting, make sure the inverter can Supplement the Grid. If you ever exceed the Inverter’s capability, it can take the additional power from the grid, and not shift to the grid entirely.

 

[zanydroid]

I guess we could start using the dryer on the low heat setting for less draw, or look at the heat pump dryers.

Problem is that dryers use slow PWM on low. It’s 5+kW for a long time (order of tens of seconds). And it is thermostat based so if you have a shit ton of wet clothes in there it will have longer duty cycle initially due to heating up all that wet stuff.

Do you have an emporia Vue installed? You will see if you have a unicorn dryer that does not do that.

A trick some people try is wiring dryer for 120V. That will drop the element to 1.25kW range. This will probably dry slower than a HP but it may end up being cheaper to implement

 

[Steve_S]

You are chasing 2 separate wild monkeys here.
1) LOOK at your appliances and consider how immeficient they are !
An Induction Stove is FAR more efficient than any other type... Rebates & Credits are available to us in Canada for them too.
2) Look at your Washer & Dryer, do you know you can get a Combo Washer/Dryer that only uses 120V ? These are ofg the Heat Pump variety and also qualify for rebates etc...
3) Your Hot Water tank,, another nasty power-pig can also be replaced with a 120V Heat Pump type that will never leave you without hot water (available up to 80 Gallon but most fid a 40Gal more than enough.

Load Shifting is not hard and not uncommon but it is not necessarily practical for everything but when used on concert with smarter efficient appliances / devices it can make a huge difference.

Simply put these are well proven, work really well and can save obscene amounts of cash. There are NAYSAYERS of course, always are, don't waste your time listening to that BS.

Currently there are several BMS' which will interact with Victron Gear and can be had for a reasonable price IF you want to DIY your own batteries. There are also several pre-assembled good quality battery packs available in various formats that can work fine as well. Keep in mind that if you want to DIY there are extended costs for tools & equipment that the average person does NOT have. Honestly, you are far better off sticking with Victron Equipment & using prebuilt batteries with Victron Compatible BMS'.

MapleLeaf = rebadged "stuff", beware of it !

 

[petee_c]

Thx all for the replies - keep them coming! Did not remember to put efficiency losses in my numbers.

Current Rates:


Some updated math.
Scenario #1
DIY battery: I can get 32 280Ah cells from Battery Hookup for about $3300USD / $4500CDN after discount. That's ~27kWh.

27kWh at 70%DoD = 19kWh energy storage used per day Mon-Fri.
10kWh loadshifted during peak times = $2.58 savings x 0.9 for efficiency losses = $2.32/weekday
9kWh midpeak loadshifted = $0.85 savings x 0.9 for efficiency losses = $0.76/weekday

Total saved per weekday ~ $3.08

Sat/Sun
19kWh weekend rate loadshifted = $1.12 savings x 0.9 for efficiency losses = $1.01/day.

Each month on average has 22 weekdays and 8 weekend days.
(22 x $3.08) + (8 x $1.01) = ~$76/month.

If I can get the project cost down to $10K (Cdn) - Return on Investment will be about 131 months. - almost 11 yrs.


----------------
Scenario 2.
If I go for a smaller battery pack (16 280Ah cells) - I would save about $2200 in system costs and still capture most of my peak weekday loadshifting. This is if I can draw 6kW from the smaller pack.

Pack size ~13.5kWh
70% DoD = 9.5kWh

Weekday savings ~$2.25
Sa / Su savings ~ $0.45

Monthly savings ~ $53/month - using 22weekdays and 8 weekend days per month

If project costs $8K CDN , payback would be about 150 months - too long. Makes more sense to go with the 27kWh pack.


----------------
Scenario 3
What if i go with a bigger 48 x 280Ah battery pack = 40kWh - ~$5K USD / $6750CDN.

Pack Size ~ 40kWh
70% DoD = 28kWh

Weekdays:
10 Peak kWh + 18 midpeak kWh loadshifted per day.
$2.32 + $1.52 = $3.84 savings/day

Weekends
28kWh loadshifted = $1.49 savings/day

Monthly savings
~$96/month

If I can keep the project costs below $13K Cdn; payback will be 135 months (11yrs 3 months)

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If I go with 80% DoD to each scenario, I was doing some calculations, then realized I'll have the main loads under the inverter, but not all of them, so unlikely I'd be able to really capture a whole lot more to loadshift.

In fact, I will likely only capture 80-85% of the energy used in the loadshifting scenario as not all loads will be in that subpanel.... another bummer.

------------
I am not adverse to looking for a new dryer. Ours was a wedding gift from my parents - 23 yrs ago.

Our water heater is a power vented NG one. It is only about 4yrs old. I anticipate another 6-10yrs from it (I've been good at anode replacement on this one)

 

[1201]

10 year payback is approximately when you'll need to buy new inverters and maybe new batteries. Inverters may be sooner.

Also, you should use .81 for efficiency. .9 going into battery and .9 coming out. That's real world efficiency. Also factor in the extra power the inverter itself will consume.

If you really want to save money, load shift away from peak hours. Do laundry at night. Put fridge and freezer on a timer, super cool or super heat your house during off peak hours.

Invest your 10k and use the interest to pay some of the energy bill. You'll be money ahead

 

[Partimewages]

10 year payback is approximately when you'll need to buy new inverters and maybe new batteries. Inverters may be sooner.

Also, you should use .81 for efficiency. .9 going into battery and .9 coming out. That's real world efficiency. Also factor in the extra power the inverter itself will consume.

If you really want to save money, load shift away from peak hours. Do laundry at night. Put fridge and freezer on a timer, super cool or super heat your house fitting off peak hours.

Invest your 10k and use the interest to pay some of the energy bill. You'll be money ahead

Plenty of tier 1 equipment Victron Samlex still running after 10 years.
Lifepo4 batteries will last that long or longer if taken care of by using within their correct range 3.000 to 3.400 volts per cell.

 

[1201]

Plenty of tier 1 equipment Victron Samlex still running after 10 years.
Lifepo4 batteries will last that long or longer if taken care of by using within their correct range 3.000 to 3.400 volts per cell.

Also plenty of inverters that dont/didn't even last two years

 

[Partimewages]

Also plenty of inverters that dont/didn't even last two years

Cheap AOIs!

 

[1201]

Cheap AOIs!

yes, but if that's what the budget dictates- that why im saying forget the arbitrage and just manage loads

 

[AntronX]

For lowest cost you want something that will backfeed your house AC grid with zero export limiter. Something cheap like this EGCSolax 6.2kW AIO can do grid backfeed but not sure if it supports zero export.

 

[petee_c]

Invest your 10k and use the interest to pay some of the energy bill. You'll be money ahead

I'm in Canada, so we are taxed pretty heavy on investments....

$10K invested to make $70x12months =$840/yr is pretty hard to do. Goverment will likely take 30% of that. Probably would need to find something that makes 11%/yr to pay the $70/month off my electricity bill....

I didnt take finance in school. maybe that's the problem.

 

[DIYrich]

Regarding 70% DoD: You could easily go 90% Dod (100%-10%, depending upon where the 100% is). Run 100% on battery from 3:55pm until 11:00pm, or they run down to 10%, whichever happens first. Charge from 11:00 pm, and set the Amps to be done by 7:00 am from 0% (the 10% will give you a buffer).

In your cost of batteries, since you are buying cells, you will also need BMS, wiring, fuses, case or rack of some type, etc.
I'd build one 48v 280ah battery now. Get some experience and see how it goes. Wait for cell prices to drop. Then consider adding more. In the 6 months since I built my battery, cell prices dropped from $150 to $105 for the same cell.

I highly recommend spending more on the inverter and getting an EG4 18kpv or Solark 15k. They will have the functionality you want (TOU settings), and inverter capacity to power most of your home without having to worry about running the oven and dryer at the same time. You can also passthrough the EV chargers. In the event of grid down, you have the option to recharge from your battery (put a few miles into the EV to get to the store and back, or to a public charger that is working).

 

[1201]

I'm in Canada, so we are taxed pretty heavy on investments....

$10K invested to make $70x12months =$840/yr is pretty hard to do. Goverment will likely take 30% of that. Probably would need to find something that makes 11%/yr to pay the $70/month off my electricity bill....

I didnt take finance in school. maybe that's the problem.

I took one finance class in school and remember 15 minutes of it.

If you kept you 10k in the bank at zero percent, assuming a life expectancy of 10 years for the alternative(inverters and battery)

You could just take $83 out every month and be even.

If you invested it at 5% you could take $106 out per month for 10 years

 

[petee_c]

I have built 2 batteries in the past. 12v for trolling motors. 4s2p.

No BMS. I typically run it down 30% before charging it with a balance charger.... Pic before adding XT60 connectors and a lid to it. This was in May 2021. Most I have drawn it down is about 50% - 8hrs on the water. It powers a kayak in place of the pedal drive.

 

[OffGridForGood]

In Canada we have cheap electricity - this makes the payback quite long for most solar.
But we also have expensive gasoline. For my area, this means a kWh is equal to 71cent of gasoline I don't buy, if we put that kWh into the Kona.
EV's for daily commuter use, make the most sense. You don't need solar to gain this advantage over gasoline prices, and EV charging from midnight to 7:00AM is not an issue for most people.
The load shifting thing is fun, and and you can build a system, with Inverter & batteries, with or without PV.