Looking @ time of use - q on "per KW" charge

[ncbill]

Considering switching from regular service (8 cents/kWh) to my utility's "time of use" schedule.

I'd pay an extra $5/month on the facility charge, 5.2 cents/kWh "on-peak" (1pm-7pm, M-F), 4.6 cents/kWh "off-peak" (this is not an interruptible service)

What I can't figure out is the "On-Peak Demand Charge per month" of $6.14 per kW.

My new heat pump will be a 3-ton Trane XL15i.

Is there a way to calculate the per-kW (not kWh) charge from the specs of that unit?

The only thing I could find on my utility's web site was a cryptic reference as to time of use would likely not save money for consumption of under 1000/kWh a month (last year it was 1800kWh/month with A/C using a 20-year old builder's grade York)

Thanks for any guidance!

[gary_g]

"On-Peak Demand Charge per month" of $6.14 per kW.

That doesn't sound right.

[ball a/c]

I would be very careful with using a demand meter. I was told that the usage is determined by the peak load within that hour, even if it was at start up. I don't see what you would gain on a residential unit.

[motoguy128]

I believe the on-peka KW charge is a penalty for the either the average Kw consumed during on-peak times. So if you still consume on average 500 Watts during all on-peak hours, then you get hit with a $3.07 charge.

The on-demand meter benefit the utilties far more tha nhte discounted rate they give you IMO. unles you have a large home that's well insulated, you may struggle to get a return... and you may have to sacrifice a lot of comfort and convenience. I don't like to wait unitl 8PM to do laundry, use the oven or more improtantly use the A/C in the summer.

Off hand it looks like you have cheap electricity ether way.

I know on my home, I'd struggle just to recover the $60/year in the billing fees alone and I think the on-peak rate is higher than the normal rate and the off-peak hours are 8PM or maybe even 9PM. So I'd have to sweat my a**-off when i get home in the summer unitl bedtime and the n freeze my a** off to store enough "cool air" for the following afternoon. No thanks.

[pstu]

Considering switching from regular service (8 cents/kWh) to my utility's "time of use" schedule.

I'd pay an extra $5/month on the facility charge, 5.2 cents/kWh "on-peak" (1pm-7pm, M-F), 4.6 cents/kWh "off-peak" (this is not an interruptible service)

What I can't figure out is the "On-Peak Demand Charge per month" of $6.14 per kW.

My new heat pump will be a 3-ton Trane XL15i.

Is there a way to calculate the per-kW (not kWh) charge from the specs of that unit?

The only thing I could find on my utility's web site was a cryptic reference as to time of use would likely not save money for consumption of under 1000/kWh a month (last year it was 1800kWh/month with A/C using a 20-year old builder's grade York)

Thanks for any guidance!
I understand what you are saying, but that is unlike any other residential TOD (time-of-day) rate I have ever seen. That really is not a TOD rate so much as a demand rate -- note that both on-peak and off-peak energy (kwh) rates are so much lower than your flat rate. Can you give the name of the utility? Almost always they post their formal rate descriptions on the internet, in what they call a "tariff book".

Most of these rates are NOT written to screw the customer, believe it or not. They are written with a goal of changing customer behavior. Usually they are written to be revenue neutral, that is a certain population will pay less even with no behaviour changes
(and a certain population will pay more). It would be very valuable to know whether you are in that population, it will depend mostly on your max KW demand. Do they offer any advice or counseling for prospective customers? Most of the time they want to help customers make the right decisions.

In the event you cannot find a better choice, you could use a device like TED to look at your usage patterns:
http://www.theenergydetective.com/index.html

Warning signs for your home would be if you use electric heating for water, if you have an electric tankless then better off to forget it. Most homes have a "Load Factor" (LF) in the .20-.40 range. Those with a 0.20 LF will have a peak demand 5X their average demand, those with a 0.40 LF will have peak demand 2.5X. So far, are you confused and discouraged, or want to know more? This is a really advanced problem compared to most residential experience, and kinda interesting too.

I used to work in the rate department of an electric utility. Took me a couple years to comprehend the important difference between KW and KWH<g>. But it makes perfect sense now.

Hope this helps -- Pstu

[ncbill]

Those numbers are directly off Duke Energy's residential time of use rate schedule for NC - "SCHEDULE RT (NC) RESIDENTIAL SERVICE, TIME-OF-USE"

Demand charge is for the summer - June 1 through September 30

I didn't consider load control (credit is all of $8/month), so the above is non-interruptible.

Every other residential time of use rate schedule I've seen is priced only in $/kWh.