Time of use electricity billing is it worth it?

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.

EbS-P

Minister of Fire
Jan 19, 2019
5,965
SE North Carolina
We have the option into enroll in time rate billing. The short is they charge and extra 3$ a month then $5.17 per Kw for the highest 15 minute (average) usage for the billing cycle. Then peak charge is $0.077 and off peak is $0.062 per KWh.

At some point EV charging will become the majority of our electrical usage. I have access to daily bar charts of my usage but I don’t have the actual data.

It seems to me without doing the math if one could keep the oven, dryer, and resistive heat strips off (that’s gonna be the killer I think but they can be on more than 5 minutes at 10kw so call it an average peak of ?????) and the steam shower 9kw one could really reduce the charcoal for you EVs.

Attached is my rate schedule and a snapshot of yesterday and today’s useage. To get Kw you need to multiply the kWh for the 15 minute interval by 4.


Is it worth it??
Anyone on time rate billing by choice or otherwise?

I can see as demand outpaces infrastructure the could be forced on rate payers or fixed rates increased to the point of making this the only choice.

Evan CB7DBDA2-544E-4935-AD14-EB4B12B588F9.png
 

Attachments

  • r2ncschedulertouddep.pdf
    97.3 KB · Views: 165
If you install an Emporia Vue, or any similar energy monitor, we'd have the data to run thru Excel against this billing algorithm, and tell you exactly what it's going to cost. I could try it on my usage over this weekend if you want, but I don't have any summer data from the Emporia... yet.
 
  • Like
Reactions: EbS-P
IMO unless you have a home battery, it may be tough to justify until you get the EV.
 
IMO unless you have a home battery, it may be tough to justify until you get the EV.
BTW, many areas that have time of use rates reportedly have had to add regulations to keep folks from load shifting with renewable generation and batteries. They are effectively charging up the batteries at night with low cost grid power and then selling power from the battery during the daytime as renewable power at higher rates back to the utility.
 
  • Like
Reactions: Ashful
A quick guesstimate if my last billing cycle 60% off peak 40% peak (probably not realistic) and 6kw peak charge. The difference was time use billing was 15$ cheaper. Our power rates are too cheap to hassle with that. I could reduce my consumption by 15% I bet if I tried.
 
My utility can look at my history and estimate what TOU would've cost on an annual basis. I think it was $150 less.

I realize I could get cute with banking heat and coolth on my Ecobee, and probably jack that up. Also, previously, I charged my EV during peak, plugging it in when I came home. New hotness is programmed to charge 12 AM to 6AM, which is like 4 cents/kWh.

The real fun would be getting a 240V timer for my HPWH, but the powered anode would not work. Hmmm.

I will look into this.
 
BTW, many areas that have time of use rates reportedly have had to add regulations to keep folks from load shifting with renewable generation and batteries. They are effectively charging up the batteries at night with low cost grid power and then selling power from the battery during the daytime as renewable power at higher rates back to the utility.
The entrepreneurial capitalist in me was already devising such a plan, the moment I read the OP. No surprise others had thought of the same. If the utilities won’t do the smart and responsible thing of installing storage, why shouldn’t a few of their customers do it for them?
 
  • Like
Reactions: sloeffle
The real fun would be getting a 240V timer for my HPWH, but the powered anode would not work. Hmmm.
You could just hack it and separate the circuits on your own. I’d like to think these HPWH mfg’s will eventually get to separating this on their own, for scenarios such as you describe, but I really doubt there will ever be sufficient customer demand to add cost for this.
 
I’ve tried banking cold last couple days. It hasn’t been hot maybe 90. Anyway down to 76 before 9. (Kids under blankets watching their morning shows). And by 5 it’s up to 80-81 and I’m getting complaints. It possible as long as the nights get below 73. If it’s a few hot days and nights in a row the brick just soaks up so much heat AC is running flat out by 4 pm to hold 80 degrees.

I don’t think we can get net metering and time of use billing. I could be wrong.
You could just hack it and separate the circuits on your own. I’d like to think these HPWH mfg’s will eventually get to separating this on their own, for scenarios such as you describe, but I really doubt there will ever be sufficient customer demand to add cost for this.
Your powered anode is integrated into the unit? I think I will add one next year. But the .6kw just isn’t that much. It’s just adding less than 3$ a month to my peak usage cost.

With an electric oven it could add 15-20$ A peak demand steam shower. Could result in 50$ peak demand charge. But worst case 10kw peak demand charge with 100% of my power at peak rate I only pay 20$ more than I did last month.

I have not looked at other time of use rates but ours doesn’t look super great untill you are chargers 2 or move EVs.
 
With how my utility net meters my solar it encourages me to load shift to the day. I pay full retail for each electron that comes in from the grid but get reimbursed the wholesale rate for each electron that my solar over produces. So we run our HPHW during the day to get ready for night time showers. We charge our cars when we are working from home. We do laundry when we’re home during the day. We run our pool pump during the day because, well it’s a pool. We run our AC during the day because.. it’s hot. We cook with electric at 5 PM (still peak rates) because we are hungry.

Their TOU peak rates are twice the standard non-TOU rates but you only get a 25% reduction during non-peak use.

Basically a lot of uncertainty of whether it would actually save money and tbh our electric bill is pretty low now all things considered. I helped them with their peak load problem when I shifted my load to solar, I don’t think TOU would do much for me.
 
Last edited:
  • Like
Reactions: EbS-P
I have been watching this thread with interest for, well, all along really.

My counsel is, if you got kids at home that have never had their own electric bill, TOU is probably a bad deal. I have 4 children, I was unable to explain to any of them how important energy conservation is. Once they got their own electric bills, they got RELIGION in all caps. I got one daughter who still takes 75 minutes showers when she comes home for holidays, but visit her place, she has an inline hot water heater that cuts out at something like seven minutes.

Local I don't have a differential between peak and off peak rates. If I did, my wife could do it but she would complain about it which would likely negate the cost savings; and those of my children who have only been in utilities included apartments wouldn't comply.

As far as the powered water heater anode, I would consider hacking it as it probably runs on 110 anyway, but I would open the control box to see the circuitry. A powered anode most likely draws a certain number of watts, changing from 220 to 110 probably won't save any money. The more important question is do you need a powered anode. Local to me I have a passive anode that gets boogered up from calcium deposits, but I have no idea what water properties anyone else has. If you disconnect the power to the anode, does your hot water start smelling like rotten eggs?

M2c
 
  • Like
Reactions: woodgeek and EbS-P
OK, I've given this some thought. The short version is that TOU looks like it can save me some money, but I'm not quite ready to pull the trigger.

I use about 18 MWh per year for everything (no HHO, natgas or gasoline usage). Of that, I'd estimate ~10MWh is space heating, 2.5 MWh is the EV, 2MWh is my AC, 1.5 MWh is my HPWH, and the rest is the small fry.

I have a smart meter, and my utility PECO looking at the last 12 mos, says I would've saved ~5% doing TOU (without doing any load timing).

And the midnight to 6 AM rate is 4 cents! The noon to 6PM rate is 22 cents.

The new EV can time its own charging to any fixed period... doing that at night both means I run on nearly all NUCLEAR electrons and would give me another 5-10% savings TOU. I already set it that way just for the carbon savings.

The HPWH is a Gen 1, 10 years old. Its never given me any trouble, but it is probably not long for this world. Also EF = 2.4, versus current tech closer to 4. A newer unit will have wifi/app control (seems standard) and setting it up for TOU will be trivial. No point in hacking the old one for a few percent savings for a few (?) years.

The big elephant is HVAC. I know if I do a setback of a couple degrees, I need no heat for 2-3 hours, and a set up I need no AC for 4-6 hours. So, with a 6 hour peak period, I can save a lot by heat/cool banking, maybe 20% of my total bill.

Other thing is I am running a (5 year old) Ecobee3. And it HAS TOU capability. w00t! Unfortunately, despite being updated, the TOU feature is not 'enabled', so I can't play with it. This is a bad sign, the help page says 'available in some areas'.

I will call Ecobee tech support (I actually chatted with their founder/CEO many years ago when they were a baby startup). If they can enable me to turn on TOU on the Ecobee, I will give it a try. I could save, I think, several hundred $$ per year. Otherwise, I will wait.

The other nice feature here is that the same changes will reduce my carbon footprint. PECO/Exelon has a number of legacy nukes running, I assume that is what I am getting when everyone is asleep.
 
One option for AC that i was not aware or until recently is 48 volt minisplit that runs directly off solar panels (no batteries). It adjusts its load on the amount of generation from the panels. That would keep the AC loads from not needing to be shifted to the night period. https://www.hotspotenergy.com/solar-air-conditioner/ The pricing is pretty close to a regular minisplit (not including the PV panels). It makes sense in a balanced climate area, when the sun is out more AC is needed.
 
I have been watching this thread with interest for, well, all along really.

My counsel is, if you got kids at home that have never had their own electric bill, TOU is probably a bad deal. I have 4 children, I was unable to explain to any of them how important energy conservation is. Once they got their own electric bills, they got RELIGION in all caps. I got one daughter who still takes 75 minutes showers when she comes home for holidays, but visit her place, she has an inline hot water heater that cuts out at something like seven minutes.

Local I don't have a differential between peak and off peak rates. If I did, my wife could do it but she would complain about it which would likely negate the cost savings; and those of my children who have only been in utilities included apartments wouldn't comply.

As far as the powered water heater anode, I would consider hacking it as it probably runs on 110 anyway, but I would open the control box to see the circuitry. A powered anode most likely draws a certain number of watts, changing from 220 to 110 probably won't save any money. The more important question is do you need a powered anode. Local to me I have a passive anode that gets boogered up from calcium deposits, but I have no idea what water properties anyone else has. If you disconnect the power to the anode, does your hot water start smelling like rotten eggs?

M2c
All very very good points about kids. I’d do enough “parenting” already. Not having to police their electric usage is worth 10$ a week to me. Sometimes you have to pick your battles.
 
OK, I've given this some thought. The short version is that TOU looks like it can save me some money, but I'm not quite ready to pull the trigger.

I use about 18 MWh per year for everything (no HHO, natgas or gasoline usage). Of that, I'd estimate ~10MWh is space heating, 2.5 MWh is the EV, 2MWh is my AC, 1.5 MWh is my HPWH, and the rest is the small fry.

I have a smart meter, and my utility PECO looking at the last 12 mos, says I would've saved ~5% doing TOU (without doing any load timing).

And the midnight to 6 AM rate is 4 cents! The noon to 6PM rate is 22 cents.

The new EV can time its own charging to any fixed period... doing that at night both means I run on nearly all NUCLEAR electrons and would give me another 5-10% savings TOU. I already set it that way just for the carbon savings.

The HPWH is a Gen 1, 10 years old. Its never given me any trouble, but it is probably not long for this world. Also EF = 2.4, versus current tech closer to 4. A newer unit will have wifi/app control (seems standard) and setting it up for TOU will be trivial. No point in hacking the old one for a few percent savings for a few (?) years.

The big elephant is HVAC. I know if I do a setback of a couple degrees, I need no heat for 2-3 hours, and a set up I need no AC for 4-6 hours. So, with a 6 hour peak period, I can save a lot by heat/cool banking, maybe 20% of my total bill.

Other thing is I am running a (5 year old) Ecobee3. And it HAS TOU capability. w00t! Unfortunately, despite being updated, the TOU feature is not 'enabled', so I can't play with it. This is a bad sign, the help page says 'available in some areas'.

I will call Ecobee tech support (I actually chatted with their founder/CEO many years ago when they were a baby startup). If they can enable me to turn on TOU on the Ecobee, I will give it a try. I could save, I think, several hundred $$ per year. Otherwise, I will wait.

The other nice feature here is that the same changes will reduce my carbon footprint. PECO/Exelon has a number of legacy nukes running, I assume that is what I am getting when everyone is asleep.
I’m still trying to understand if the $5.17 per Kw peak usage fee is something other utilities charge. One pizza night could cost me 25$
 
One option for AC that i was not aware or until recently is 48 volt minisplit that runs directly off solar panels (no batteries). It adjusts its load on the amount of generation from the panels. That would keep the AC loads from not needing to be shifted to the night period. https://www.hotspotenergy.com/solar-air-conditioner/ The pricing is pretty close to a regular minisplit (not including the PV panels). It makes sense in a balanced climate area, when the sun is out more AC is needed.
I’m going to post this to a new thread. There is enough experts here to help me understand the advantage of this vs an off grid inverter vs grid tied system.

Look for it later today
 
Well, it's been a very unusually-cold June here, we're caught on the opposite side of a very abrupt front from the rest of you folks experiencing unusually hot weather. But even so, 22 days into the month, I see our peak 15 minute-averaged usage is 10.9 kW.

@EbS-P, you said you'd be billed $5.17/kW for your highest 15 minute usage, which would be a $56.35 adder to your bill for those 15 minutes, if you quoted the pricing correctly. However, I can't help but think you actually meant to say $5.17/kWh (not "kW"), which would cost you only $14.09 for that short time window.

Not that I'd ever wish for hot weather, but it would be nice if we had some data from someone in the thick of it, to run against your pricing. Likewise for someone running heat pumps in real winter weather.
 
Well, it's been a very unusually-cold June here, we're caught on the opposite side of a very abrupt front from the rest of you folks experiencing unusually hot weather. But even so, 22 days into the month, I see our peak 15 minute-averaged usage is 10.9 kW.

@EbS-P, you said you'd be billed $5.17/kW for your highest 15 minute usage, which would be a $56.35 adder to your bill for those 15 minutes, if you quoted the pricing correctly. However, I can't help but think you actually meant to say $5.17/kWh (not "kW"), which would cost you only $14.09 for that short time window.

Not that I'd ever wish for hot weather, but it would be nice if we had some data from someone in the thick of it, to run against your pricing. Likewise for someone running heat pumps in real winter weather.
It’s the demand charge Kw not kWh. It’s a pretty severe charge If you ask me and really doesn’t incentivize any residential customers to switch. Looks to me That I have not exceeded 5 kw. Take the peak 15 min kWh and multiply by 4.

But it only takes one whole load in the dryer or a steam shower or the oven preheating or a defrost cycle in the heatpump (10kw strips kick on with the compressor in high and the blower on extra high) to run that whole bill up. I would rather see peak rates above the standard rate and off peak below. Having both peak and off peak below standard rate is a bit confusing then you ad the peak demand charge.

Peak rates end at 9pm both summer and winter.

Having only a 3 ton unit for 2000 sq ft up and 1000 down with a 17’ insulated glass garage door make my usages unique. Usage for the hottest day of the year 86 degree average 24 hour temp. Did some cold banking in the AM. AECF8D5A-FC0D-4E97-BD45-0167117AB0DB.png
 

Attachments

  • r2ncschedulertouddep.pdf
    97.3 KB · Views: 87
Every single person in our area that switched to "smart hours" has seen an increase in their bill. The whole "let us micromanage your electricity" is just another way to shaft you. We're still on the ancient spin-o-meter and have refused smart meters every chance we get. Eventually they'll force it on us but until then we're happy with our dinosaur.
 
Having both peak and off peak below standard rate is a bit confusing then you ad the peak demand charge.
Making it as confusing as possible is a good way to sell potential customers on potential benefits, while brushing unforeseen reality under the rug. Sure, there are ways you could save money on this billing scheme, but it seems unlikely that most will. You need to give them some credit for the pure evil genius of selling it as a savings to their average customer, though.

Reminds me of some of the mortgage lending practices that led us into the 2008 meltdown. Both are very disappointing but clear examples of the fact that a very large fraction of our population cannot handle even the most basic (3rd grade level?) arithmetic.
 
Since we got a smart meter the load control device on our AC that we get an annual 20$ credit for has not been used. They know we aren’t pulling much so they don’t shut the ac off???? That’s my guess. Smart meters mean I don’t have to report an outage anymore. They know within 15 minutes that than I’m without power. Could not have gotten my smart usage gateway for free if I didn’t have the smart meter. All in all the smart meter is fine. Changing rate structure is another separate decision that a smart meter enables.
 
Here is the absolute lowest use for a hot day. Maybe made 95 but the morning was cool. Didn’t use the oven and did takeout for dinner. The egg rolls in the oven last night made a big difference of $7.50. So by not cooking ever in your oven you can save less than 8$ a month.

Got up in the attic. Crawled to the eves. Some spots up there are much to have 3” of insulation.

D4BC6A45-CC6C-491D-AC38-1756BD2D0AA2.png FC0D7FA4-9ED2-4680-8950-84315B6DB42F.png
 
Not quite following you. You said you saved $7.50 in one day by not cooking dinner (but likely spent more in take-out), but then translated that to < $8/month. What's the conclusion?

Looks like you're averaging 40 kWh/day, with a typical monthly 15min peak at 5 kW?
 
My thoughts was that by not cooking dinner I Dave’s 7.50 a month. (Takeout is 5x-10x times that was the joke in my head).


Is say that 40 kWh was about right. 5kw 15 min peak is about right. But one load in the dryer and that could spike to 8 kw Now that I’m charging an EV a busy week can add substantially to usage.

I lost a broiler element in the oven and haven’t replaced it. So that likely will add another 1.5kw to the on peak demand charge.

We have been very dry so the dehumidifier has not had to run. But that could be kid shifted to off peak.

I do think if you had a variable speed compressor and you could limit its consumption during on peak times your hvac use could be kept in check if you didn’t mind temp swings. The ac was on the morning cooling everything down to 76. Then off until about 5:30-6. If you could keep in my case the ac only running on low stage until 9 pm I think you could keep the house livable. But on a hot day in August I beat it would get up to 82 inside.

In short I’m past the point in my life where saving 40$ a month is vital. If I wanted to save more than that I’d tell my wife no more drive through coffee. But who wants to fight that fight😉

I would be interested to see others time of use rate schedules.
 
It's been extremely (freakishly) cool here for June, so not much AC usage. but we're at 1690 kWh at 23 days into June. Past months have been 1600 - 2000 kWh, other than December's 3030 kWh, thanks to tens of thousands of little twinkling Christmas lights. As noted previously, our peak 15 minutes at this point in the month is 10.9 kW, although I'd really like to see how high that goes on a truly hot day. With all four AC systems firing, my wife doing laundry and me working in an air-conditioned shop on a hot Saturday, I suspect we might almost double that peak number.
 
  • Like
Reactions: EbS-P