Higher than expected electric bill

Discussion in 'Clarity' started by turtleturtle, Nov 25, 2020.

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  1. MrFixit

    MrFixit Well-Known Member

    Yes, except for the very small difference in 'efficiency' that has been observed (L2 has a slight advantage).

    In other words, a full charge with an L1 charger may require 14 kWh from the wall outlet, while that same charge would maybe require 13.5 kWh from the wall with L2. The extra energy for the L1 charge is lost as heat somewhere along the way.
     
    turtleturtle likes this.
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  3. 76CDF61B-87E0-4B8C-9A04-1C02D4F8F5C9.jpeg
     
  4. I wonder if he got paid for his time when he figured that out.
     
  5. PHEVDave

    PHEVDave Active Member

    Actually, yes, it could. There are other things going on during charging that could make charging at 120V less efficient. For example, there could be cooling/heating pumps, fans, etc. that are used during the charge cycle. So a shorter charge cycle (Level 2 - 240V) could be more efficient. I am not sure how significant this would be in the case of the Clarity but, I also own a Chrysler Pacifica PHEV and many of the people “in the know” in that particular circle claim that the difference in efficiency between Level 1 and Level 2 charging is significant.

    I’m not saying that the Clarity is the same in this regard but there is certainly a possibility.
     
    Last edited: Nov 28, 2020
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  6. PHEVDave

    PHEVDave Active Member

    We have a very similar situation to yours except that we have two PHEVs that charge up at night in the garage. For us, even before the pandemic when we were driving quite a bit more, there was not more than a $20-30 difference in our electric bills compared to before/after owning the PHEV.

    I do take advantage of demand-based rates and charge the cars at night for a savings. Our average cost per kWh is usually around 8-10 cents including all taxes and fees. We have an almost 4,000 square-foot house with two refrigerators and a freezer running 24/7 but our total electric bill last month was $84. If your bill actually increased by $100 a month and you don’t drive the car more than 750-1000 miles a month then I’d be very suspicious. What you are describing sounds a lot like a demand based rate which imposes a penalty for high usage during peak hours. Your electric bill should indicate how many kWh you used for the month. If you’re paying 10 cents a kWh and your bill went up $100 then you should see a very significant increase of close to 1,000 kWh when comparing pre-PHEV to post-PHEV electric bills.
     
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  8. PHEVDave

    PHEVDave Active Member

    Also, the “charger” really isn’t going to affect the efficiency of charging much if at all. The more correct term for it is “EVSE” and it really is not much more than a smart switch that turns the current on or off to the vehicle. The real ‘charger’ is internal to the vehicle.
     
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  9. craze1cars

    craze1cars Well-Known Member

    I have always tracked my electric usage and cost pretty detailed. Here in Indiana our electric rate is flat 24 hrs a day and about .10 per kWh much like @turtleturtle. Prior to owning Clarity, annual bill was $2,303. After owning Clarity annual bill now $2,664. So Clarity costs me $361/year = $30/month. We drive it about 18k miles per year, guessing about 50% electric and 50% on gas.

    As an electrician, I recommend looking elsewhere in the home for a draw that wasn’t there previously. I’ve found and/or fixed all kinds of interesting causes for sudden jump in a customers bill. A few 100 watt lights accidentally left on 24 hrs a day unseen in attic or crawl space? Leaking hot water pipe inside slab construction floor leaking hot water to ground? Electric water heater tstat stuck or accidentally set too hot? Well pump check valve failed and therefore pump cycling 24 hours a day to keep water pressure up? Same for sump pump check valve? Tstat controlled Attic fan failed and stuck on? Roof/gutter ice dam prevention heat coils left on unknown? Same for electric water pipe wraps? Electric blanket or mattress pad in a guest room left on? Many utility companies will come to home for free and do an analysis to help find the usage leak. Call your electric company and express your concern they may likely help with this.

    I do not suspect your car or charger. For light use and short local drives it might account for $15 to $20 month.
     
    Last edited: Nov 28, 2020
  10. Electra

    Electra Active Member

    Is not on your bill, check your online account. My online account lets me see my usage hourly in the pic below. I have tier pricing, $0.15/kWh between 6-8am and 3-8pm, $0.05/kWh at other times with a $12 monthly fee. So my average last month with taxes and fees was $0.071/kWh.
    Screenshot_20201128-081106.png
     
    Last edited: Nov 28, 2020
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  11. There are fans and pumps that are part of the battery cooling system and they do operate during charging. It is likely that the higher L2 charging rate will create more heat in the batteries which may cause the fans and pumps to run more frequently and for longer periods while charging, compared to L1 charging.

    Either way, the difference between the 2 methods is probably less than the amount of energy used to transmit this post.
     
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  13. craze1cars

    craze1cars Well-Known Member

    Another very common cause I neglected in my list above: Air source heat pump failures, often undetected by homeowner and resulting in home heat system running on backup resistance heat, instead of heat pump heat. ESPECIALLY this time of year as we recently entered heating season.

    Much depends on how alert and aware a homeowner is about their home’s systems and their proper operation. Some are very keen to what their house is doing, many are completely clueless. And many are somewhere in the middle.

    I still firmly believe the car/charger configuration is irrelevant, as it is highly unlikely to be the culprit for what is being described here.

    I will also point out that COVID has notably increased electric bills for many, especially if a commuting family is now a stay at home family. This can easily add $100/month to many households.

    Look elsewhere in the home for the problem. I am confident it’s not the car or charger.
     
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  14. turtleturtle

    turtleturtle Active Member

    I’m inclined to agree. Trying to track it down, as the math doesn’t add up.

    We have a non-believer in the house that is convinced it’s the car. Isolating that outlet with the kilowatt meter is the next thing to prove it’s not the car.
     
  15. rodeknyt

    rodeknyt Active Member

    If you have the capability to retrieve your bills from a year ago, look at the actual KWh usage and the rates that were being charged at that time. My bill is noticeably higher than last year, but it is because the rates went up. They have a way of slipping rate hikes in without telling you.
     
    HarryP likes this.
  16. PHEVDave

    PHEVDave Active Member

    Another example of something that would cause the 120V charging to be less efficient is the voltage drop on the wires which is not as significant at 240V.

    https://www.researchgate.net/publication/272377451_Assessment_of_Level_1_and_Level_2_Electric_Vehicle_Charging_Efficiency
     
    Last edited: Nov 28, 2020
  17. And you sit in a dark room during that time?

    Is the rest of the family at home during time they would normally be at school? Do you have incandescent lights?

    If they are really convinced it's the car, here's an experiment--starting on the first billing day, for a month, don't charge the car. Run it on gas for a month, then look at your usage.
     
  18. turtleturtle

    turtleturtle Active Member

    That’s interesting. I could try the negative case to rule it out.
     
    David Towle and insightman like this.
  19. Keith

    Keith New Member

    I used a Tp -link kasa smart plug with energy monitoring to measure my clarity charger useage in the past.
     
  20. I am with craze1cars on this question. We own 2 full electric vehicles here, our electricity costs about the same as the OP (we live in Québec so it's flat rate at 0.10$/kW tax included) and we drive our cars daily with regular charging needed, but our overall bill is only about 50$ to 60$ more per month. I have a feeling that something else in the house is causing a drain.

    If you really want to monitor your exact charging use then I would suggest a quality L2 smart charging station. I have the Flo X5 that e-mails me detailed charging reports and includes total power used down to the thousandths. My wife's charger does not e-mail reports, but the Station Verte charging station displays all of the metrics on the screen. Both are made in Canada and of very high quality. If you already have an L2 charger then you could look into a power monitoring device that hooks into your panel, but those are not always very precise regarding which devices are pulling power (according to what I have read).
     
  21. ticker47

    ticker47 New Member

    Not sure if the OEM charger you have is the same that comes with the BEV (What I have), but the max draw rate on it is 1.38 kW as measured by the smart plug I use with it. Even if it was drawing max power all day (it doesn’t as it ramps down when getting close to fully charged) you’re still looking in the realm of 33 kWh/day. Some quick and dirty math puts the max increase with your rate at 92(with the charger running 24 hours daily in a 31 day month). I’m with others here that its not the car.
     
  22. papab

    papab Member

    Something doesn't jive. Average daily usage is up by only 20%, but bill went up by $100??
    If you want to see what's going on in your whole house elect system, get an iotawatt system.
     
  23. DerekA

    DerekA New Member

    Did you have the charger installed by a professional? I drive ~25 miles a day and we've seen ZERO increase in our electric bill. I'd get that wiring checked out...
     

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