Time of use meter

[Vettes980]

First time poster with a 2012 allocation.

I'm trying to figure out if a TOU meter will benefit me. Progress Energy Carolinas has two options. One is a no fee meter where on peak is about .16$/KwH and .05$/Kwh for off peak. The other is on peak at about .06$/KwH and .05$/Kwh for off peak but has a $5/Kw summer surcharge and $3.75/Kw winter surcharge.

My usage hovers around 350-400 KwH and 700-800 during June-August per month. My normal rate is .11/KwH and I think that adding the Volt and going to no fee route will essentially be a wash and maybe even more during the summer months, but I don't know how my usage translates in a number of Kw and the associated surcharges.

Thanks for any help

Greg
Future owner...2012 Summit White w/ Jet Black and Spice Red

[Sheffield]

I'm not sure I understand what the surcharges mean.

A spreadsheet would be the way to get a clear answer.

[Grumpa]

The $/kw surcharge is probably based on your peak usage during your billing month. This is relatively common in industrial power applications. It is there to discourage you from using large amounts of power (in kw) for short time periods because power companies have to design for peak power so by lowering the average using peak surcharges, they can reduce operating costs. I am curious what time frame your peak surcharge would be based on.

[bonaire]

You have pretty low usage numbers (congrats!) compared to a 2-story single-family home like ours. Our spring numbers are great this year and I'm pretty steady at 1150 kWh/month or so for the last 4 months. Our rates here are flat .167/kWh and will hit .175/kWh in the summer.

The last rate with the fees sounds intriguing. I wonder what the fee amounts to for your home? If you intend to charge the Volt nightly and the TOU meter is free (or is it an add-on cost?) then one of the two TOU plans could be a good solution.

Take all the costs into account such as if a meter has a cost. Then if you charge fully nightly at about 13 kWh for five work days and at least once more over the weekend, that is 13x6x4 = 312kWh more per month. Monthly charging would cost $15.60 @ .05, $35.31 @ .11 = monthly savings of $20, yearly of $240. Now, if you only 1/2 charge nightly after driving say 20 miles a day, then the savings are 1/2 that ($10, $120) so your Volt driving style will be your primary driving factor in the decision. If you intend to drive over 12,000 a year and most of it on electric charged at night, the TOU rates seem really good.

A spreadsheet would work to have you figure out the best option. As with any utility, they have the rights to change tariffs every year through a petitioning process. So, today's rates could change as TOU gets more prevelant and other factors of energy usage change.

[Vettes980]

You have pretty low usage numbers (congrats!)

Thanks, I try to do my part. Flourescents and keeping them off when I don't need lights. I of course don't have any kids running around turning things and not off etc etc so that helps.

My main question I guess was how does my usage translate into kW so I can calculate how many"kWx$5" I will have to pay. For the savings to be beneficial it would have to be 3 or less bc as you point out, I am only saving $20 a month by going from .11 to .05. There is no cost for the meter or install btw.

[DonC]

You're rates are so low I'd just stay with what you have. You'll get about 4 miles/kWh so 1000 miles will be 250 kWh or about $25/month. One thing to keep in mind is that the limited battery capacity of the Volt means that a TOU plan is not that useful. On a weekend or even during the week you might want to charge it more than once a day, and TOU usually have very high rates during daytime hours. Some people envision only charging at night but that isn't realistic IMHO.

[VoltWI]

Your peak kW demand will be based on what you run at the same time. In my house I average a minimum of 0.2 kW all the way to 17 kW. My average usage with lights & TV is about 1 kW, my furnace uses about 1 kW, A/C 4 kW (4 TON) Steam Shower 8 kW, Oven 3 kW, etc... If you have a electric water heater add 5 kW (I don't). So, my peak demand charge would be 17kW * 5 = $85.

[bonaire]

The TOU without the fee seems more appropriate.

Does the TOU have any difference on weekends? You may be charging during the day on weekends at some point if you return from an errand and then plug in at noon or something like that. Problem in summer is that daytime rate and A.C. running. So, I may have been wrong above in thinking the TOU is the way to go. $0.11 per kWh now is not bad at all. A full charge will take about 13 kWh or about $1.40 for your 40-50 EV miles in many months. Very good price for that distance.

You could look for a low-cost Solar installer to put up 4-8 Solar panels on the house and then go TOU. The Solar would be doing a majority of the work in the summertime with A.C. and would cover your Volt recharging on weekends during the days too. A small solar system would have a somewhat sizeable up-front cost but your state may have pretty good rebates. Solar PV isn't for everybody, though, and it may be cost prohibitive or have poor return on investment. You also may have trees restricting your sunlight, etc.