1. Attachments are working again! Check out this thread for more details and to report any other bugs.

First electric bill since charging begun.

Discussion in 'Prime Fuel Economy & EV Range' started by chenderson2, Jan 22, 2018.

  1. Son of Gloin

    Son of Gloin Active Member

    Joined:
    Jun 16, 2008
    421
    320
    0
    Location:
    Lafayette, IN
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Premium
    I have one of those (Kill-a-Watt) thingies, too, and - as it seems I always have too much time on my hands - I set up a spread-sheet to track kWh "consumed" per hour of charging time. This may-or-may not fluctuate a bit for any number of reasons (I really have no idea if ambient air temp or other "stuff" might cause fluctuations?), but SO FAR:

    The highest kWh consumption rate per hour of "PIPPPIN" being plugged in (this is after 60-ish full OR partial charges totaling about 250 hours of being plugged in) has been 1.385. SO (as an example): if plugged in for 5 hours, that's 6.925 kWh consumed.

    ALSO: As far as cost per kWh is concerned, I take the TOTAL of our electric bill and divide it by the TOTAL of kWh consumed during the billing cycle to get a "factual/final/absolute" cost per kWh.

    And LASTLY "so": As we now have solar panels and a net metering "contract" with DUKE Energy, our cost-per-mile for electric driving is going to be REALLY low if-or-when our array generates more kWh in a billing cycle than our household consumes... and that would be including the charging of the car....
     
    padroo likes this.
  2. Oniki

    Oniki Active Member

    Joined:
    Jun 10, 2017
    652
    499
    0
    Location:
    Colorado
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Plus
    Congrats on the PV, @Son of Gloin

    You cost/kwh is wrong because it includes fixed charges.

    My electric bill is a good example of why your approach gives funny numbers since I am not a heavy user but my connection fee is $32 a month: Since I use about 220 kWh before net metering is calculated, your method says I pay 5400/220 = 24.5 cents a kWh, and yet 221 kWh (one more) actually costs me 11 cents more.

    In actuality, I am a net producer of kWh for my utility but I still pay $32 a month. So according to you, I pay infinite dollars per kWh ;-)
     
    #22 Oniki, Feb 8, 2018
    Last edited: Feb 8, 2018
    Son of Gloin likes this.
  3. Son of Gloin

    Son of Gloin Active Member

    Joined:
    Jun 16, 2008
    421
    320
    0
    Location:
    Lafayette, IN
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Premium
    Yes, it does (include fixed charges), but "wrong or no", that's how I determine our TOTAL (absolute) cost per kWh consumed.

    Perhaps "net metering" is determined by varying methods in different states / by different utility companies? As an example:

    For the billing period ending in December, our solar array produced / "gave" us 398 kWh...
    but DUKE charged us for the 265 kWh we "took" from the grid...
    for a total of 663 kWh consumed by the household...
    and the TOTAL cost (electric bill including riders / fees / taxes / etc) was $48.98...
    so $0.0738 per kWh consumed....

    At that rate for a five-hour charge for the car we paid about $0.51.

    If our panels ever produce MORE than we actually consume, then perhaps 750 kWh at a total cost of perhaps $22.50 (a guesstimate of what we might owe DUKE even though not taking ANY kWh from the grid) would equate to a "cost" of $0.030 per kWh... not the "infinite" cost per kWh you allude to above....
     
  4. Oniki

    Oniki Active Member

    Joined:
    Jun 10, 2017
    652
    499
    0
    Location:
    Colorado
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Plus
    For sure, net metering rules vary by utility. If you do not have TOU you will be closer to what I have ...

    First, my utility has no idea and could not care less how much my PV array generates. All they know is what their meter on my house tells them, which are two pieces of information:

    1. How many kWh I sent them;
    2. How many kWh they sent me.

    All the kWh my PV array generated that were consumed by me are invisible to them. This is an important point!
    E.g., my inverter tells me that I generated 2780 kWh since my array went live in September. The utility meter tells me that I have sent them about 1600 kWh and they have sent me about 600 kWh. If I wanted to know my consumption over this period, I would calculate
    (2780-1600)+600 = 1780 kWh

    Until recently, I was charged every month my $32 connection fee and 11 cents a minute for every kWh they delivered. Once a year they would then note how many kWh I sent to them, and I would be issued a credit. Now, every month they count delivered, received, and kWh credit and if I still have a kWh balance I am charged $32 whereas if my total kWh delivery is more than sent to them plus any balance, I am charged $32 + net delivery to me * 0.11. Once a year in April if I have any kWh balance I am paid 4 cents a kWh and then my kWh balance is at zero for the new year.

    ----
    One of the basic problems with simply dividing kWh into cost is that you cannot say with any accuracy what your bill will be if the your consumption changes because the change in consumption does not have fixed costs. So accept the annoyance and think of your bill in two parts: fixed and variable, where variable is your consumption charges per kWh. This has the additional advantage of knowing exactly how much your connection to Duke costs you, and when a Telsa battery(s) is cheap enough to let them go.
     
  5. ct89

    ct89 Active Member

    Joined:
    Dec 31, 2010
    323
    266
    1
    Location:
    New England
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Advanced
    My expectation is that utility companies are going to stop allowing you to send them electricity at the same rate they send it to you. If they don't need it, why should they essentially pay someone for sending it to them? When they send it to me it is because I need it.

    I'm actually OK with this model but I suspect it will have a rather dramatic impact on the economics of home solar installations.
    Do others believe this is where we are headed or do you think electric companies will be forced to pay for something they might not need?

    Now the "need" side of this is interesting as well. The electric companies could choose to buy from home solar instead of buying from gas/coal plants if the home solar was less expensive per KWh...That would be kinda cool to have real price competition on how our electric grid was supplied. Could I offer my excess solar for less that a power plant and under cut them? I wonder what the raw electric rate really would be in a market like that?

    BUT, don't forget that the electric company needs to supply peak needs and power plants must be built and paid for to meet those needs so somehow the power generators are going to need to get their money even if homeowners are trying to undercut them. Would homeowners be willing to pay $1/KWh on cloudy days because their solar wasn't producing anything and their electric company was forced to buy all the power needs from gas/coal plants who were pissed because they were not needed on sunny days and trying to recoup profits?
     
  6. Oniki

    Oniki Active Member

    Joined:
    Jun 10, 2017
    652
    499
    0
    Location:
    Colorado
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Plus
    That day is far in the future, even for CA ... if ever.

    You should also understand that local shared generation has benefits to the utility in terms of equipment longevity (less load on transformers) and decreased demand charges from the non local generator. As one example of the latter: my electric co-op buys coal generated electricity from the regional wholesaler at 4 cents a kWh but if you take the total cost they pay divided by the kWh it works out to 7.6 cents a kWh. The difference is demand charges.

    In terms of equipment, PV (or "DG," as the utilities like to call it) will bring TOU charging. It is inevitable. Flexible demand will be shifted to local supply. I already do this voluntarily by charging my cars at night and letting my street use my local PV during the day. The transformer loads drop and longevity increases.
     
  7. benagi

    benagi Active Member

    Joined:
    Jan 4, 2012
    525
    280
    4
    Location:
    Utah
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Advanced
    To those who have solar on their roof , what type of solar panels did you get and how large is your system . I’m thinking about adding solar to our here in UT. We have a very good south facing roof without obstructions.
     
  8. chenderson2

    chenderson2 Member

    Joined:
    Feb 6, 2010
    94
    57
    0
    Location:
    Houston
    Vehicle:
    2017 Prius Prime
    Model:
    Plug-in Advanced
    I just got my second electric bill since using the charger. However, I have been using a level 2 charger this month and my bill went down again to within $3 of the bill I got before I started using a charger. My conclusion is that using a 220 charger is more efficient than the 110 charger.
     
  9. Oniki

    Oniki Active Member

    Joined:
    Jun 10, 2017
    652
    499
    0
    Location:
    Colorado
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Plus
    Was your bill exactly the same month after month before the EV came home ?
     
  10. pilotgrrl

    pilotgrrl Senior Member

    Joined:
    Jul 23, 2017
    891
    1,797
    0
    Location:
    Chicagoan in TX
    Vehicle:
    2016 Prius
    Model:
    Three
    Who are you using? And are you stuck with Oncor to deliver the power?

    My contract with Reliant is almost over, and I'm looking to cut my rate. The delivery charge/kWh is more than the cost of the power (100% wind)!

    Posted via the PriusChat mobile app.
     
  11. Oniki

    Oniki Active Member

    Joined:
    Jun 10, 2017
    652
    499
    0
    Location:
    Colorado
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Plus
    That is a Good (tm) thing.
     
  12. enerjazz

    enerjazz Energy+Jazz=EnerJazz

    Joined:
    Feb 18, 2004
    256
    144
    4
    Location:
    Fairview, TX
    Vehicle:
    2007 Prius
    Model:
    III
  13. Larry F.

    Larry F. Junior Member

    Joined:
    Jan 22, 2010
    27
    11
    0
    Location:
    Issaquah, WA
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Premium
    My arithmetic with power rates in the Pacific Northwest is about the same. However, I think the planet comes out better with the plug-in even it the $$$ are a push - the mass generation of electricity, even if it is generated by burning coal (ick!) can be made more efficient than the small-scale energy converters we can drive around. Our power here is largely hydroelectric, with is NOT carbon zero, given the resources necessary to pour millions of yards of concrete, not even considering the impact to migrating salmon. But that is a different story.
     
  14. Dennis_MA

    Dennis_MA Active Member

    Joined:
    Jul 20, 2012
    185
    109
    0
    Location:
    Amherst, MA
    Vehicle:
    Other Electric Vehicle
    Model:
    N/A
    I have a 5 mile commute each way to work and routinely do errands after work. I end up charging every day. I estimate that my electric bill is around $25 more each month with the 240 volt charger. My workplace has several Chargepoint stations but they are a 20 minute walk from my office. I use them when I have an appointment that takes me out of town. They have a special rate with Chargepoint so a charge from empty is about $.60
     
  15. Wolfie52

    Wolfie52 Senior "Jr" Member

    Joined:
    Oct 18, 2009
    143
    124
    1
    Location:
    No. Carolina
    Vehicle:
    2017 Prius Prime
    Model:
    Plug-in Advanced
    I have a 2100 sq' home, with 3 people. I use electric for laundry, have electric (battery) lawnmower, edger, trimmer, as well as a 13' PiP and now a 2017 Prime. I do have efficient bulbs, a solar porch lamp, but other than that don't do much other than watch my usage and curtail what I can.

    My power company (Duke) sends out (as well as having the same info on the web) as to how I compare with my neighbors re electric usage. My house was not ever posited as an "energy efficient" home, but I routinely use less electricity than not only my neighbors, but I am also routinely below what they classify as "efficient, read=EXPENSIVE" surrounding homes.

    If you have reasonable measures in place it isn't difficult to be "efficient". We use AC (we are in the south!) but are smart about it. I often find my neighbors using so many wasteful practices....I have to keep the peace so...

    I never even noticed much if any increase in my power bill when I got my 1st PiP 2+ years ago. I will admit that I will charge at a free chargepoint station if I can, but do charge both of my Prius cars at home to take advantage of the EV range.
    Efficiency.jpg
     
    pilotgrrl likes this.
  16. El Dobro

    El Dobro A Member

    Joined:
    Jul 12, 2011
    7,028
    3,241
    1
    Location:
    NJ
    Vehicle:
    Other Electric Vehicle
    Model:
    N/A
    Don't forget to use power strips to shut off parasitic draws on things that don't need to be on all the time. ;)
     
  17. chenderson2

    chenderson2 Member

    Joined:
    Feb 6, 2010
    94
    57
    0
    Location:
    Houston
    Vehicle:
    2017 Prius Prime
    Model:
    Plug-in Advanced
    We have no choice but to use Centerpoint for delivery, and most providers charge much less per kWh than Centerpoint charges us for the delivery. Centerpoint charges around 6 cents per kWh for delivery. My current provider is charging 3 cents per kWh.
     
    pilotgrrl likes this.
  18. Son of Gloin

    Son of Gloin Active Member

    Joined:
    Jun 16, 2008
    421
    320
    0
    Location:
    Lafayette, IN
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Premium
    I know... it's been "forever" since I've been around these-thar "hills" (sorry), and while this doesn't specifically pertain to "first electric bill since charging began", I hope this is close enough to being on topic, and it will likely be of interest to many:

    Our most recently received electric bill (billing cycle ending on the 19th of March) was the FIRST bill we've received a) since owning our PRIME *and* b) since having our roof-top solar array up'n'running *and* c) in which our roof-top's solar production at LEAST equalled our total electrical consumption for the month. We consumed a total of 622 kWh, whereas our solar panels produced... wait for it... 622 kWh.

    So, for the month, we owed "DUKE Energy" their standard / residential "Connection Fee" of $9.40, plus Indiana State Sales Tax of $0.66, plus ... wait for it... NOTHING ELSE!

    Our TOTAL electric bill was $10.06 (around here, $10.06 will currently get you about 3.6 gallons of gas)... and that included enough "juice"... about 45 kWh... about 34 hours of at-home charging time to get about 175 miles of local / in town driving out of PIPPPIN....
     
    Oniki likes this.
  19. Travis64

    Travis64 Member

    Joined:
    Jan 14, 2018
    80
    37
    2
    Location:
    Ny
    Vehicle:
    2017 Prius Prime
    Model:
    ----USA----
    Has anyone signed up for NRG at walmart?

    They offer me 2.5 cents per killowatt for 3 months
     
  20. Glenn G

    Glenn G Member

    Joined:
    Jun 2, 2018
    117
    63
    0
    Location:
    North Andover
    Vehicle:
    2018 Prius Prime
    Model:
    Prime Premium
    I share a 2 family house - we have separate meters but many items are inter mingled - long story. Even though I occupy floors 2&3, the panel that energizes the Garage where I charge is on the first floor's panel - so I've decided to pay for my share of added electricity consumption by charging only when the battery is exhausted.

    After scouring our electric bill I was surprised to find that our cost here in relatively expensive MA is $0.115 / KW. So I re-imburse the house $0.77 per charge, or
    6.7 KW x $0.115.

    I could easily charge at my office, but the rate there is a commercial rate - ~$0.20 / KW. Next I'll have to figure how far I go on a charge.