Average Hourly Electric Usage – EV Households Versus Non EV Households


Late at night and during the wee hours of the morning, households with electric vehicles consume a lot more juice than a typical household.

This is not surprising at all to us, as time of use metering and off-peak reduced electric rates mean that most EV owners charge overnight, but still it’s interesting to see this on the graph.

According to Opower:

“Today we once again crack open Opower’s energy data storehouse (the world’s largest, spanning more than 50 million households worldwide) – this time to examine the energy usage behavior of an increasingly important segment of utility customers: electric car owners who charge their car in the wee hours of the night.”

“To fuel our analysis, we evaluated anonymous data from about 2,000 night-charging EV owners in the western US…”

“Our statistical findings suggest how vastly EV owners’ energy profiles can deviate from normal…”

In regards to the graphic shown above, Opower states:

“In the hourly usage curves, you can see that the EV owners in our dataset (light blue) exhibit a massive spike in electricity use beginning at midnight, shooting up to around 4 times the average level.”

Again, we’re not surprised by this, but seeing it on a graph shows how dramatic a difference owning an EV makes in regards to electric usage (provided you’re not on solar).

Source: Opower

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66 Comments on "Average Hourly Electric Usage – EV Households Versus Non EV Households"

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Nice. I’m glad to see that people are using the features that let them determine when the car will charge itself.

Stunned that no one has mentioned THIS 3,000lb elephant slinking around this forum! QUOTE BLAST/ “[…]”A conservative estimate is that we have an amount of electricity unused at night that’s equal to the output of 65 to 70 nuclear power plants between 6 p.m. and 6 a.m.,” Senator Lamar Alexander (R-Tenn) stated before the Senate Energy and National Resources Committee. “I suspect that’s probably our greatest unused resource in the United States. If we were to use that to plug in cars and trucks at night, we could electrify 43 percent of our cars and trucks without building one new power plant.[…]” “[…]U.S. power companies generate surplus electricity at night equivalent to the daytime output of 65 to 70 nuclear power plants, Alexander said, and that electricity could be charging batteries in electric cars.[…]” Crickets? I think not! Links Goes To Torque News And Forbes- 1)Torque News http://www.torquenews.com/397/senator-alexander-unused-electricity-our-greatest-national-resource 2 Forbes http://www.forbes.com/sites/jeffmcmahon/2011/05/20/lamar-alexander-uses-gas-prices-to-press-republicans-on-electric-cars/ Night time spiking? Loving it as Electric Fuel saves me over $200.00 a month in fuel costs vs gasoline by per unit costs. Based on the information provided above, if true, then $1 worth of waste Electric Fuel, off peak, that gives me 40 miles or so of daily… Read more »

What’s really intriguing to me is:

if you don’t charge an EV – why would your consumption at 2-3 AM be around 80% what it is at 7-8 AM? What do people do – blast the AC/heater all night? Throw a party? Or is this a hand-drawn curve?

I would say its the opposite – they turn the heat/AC down before going to bed. It then resumes normal cycle by 7am and flat base load through the day.

EV owners have a spike in the morning, likely from preconditioning.

The refrigerator, DVR, alarm clock, electronics even in sleep mode, etc. all take some power. The timer feature let me schedule the dishwasher to run at night. Also, these are averages and not everyone works 9-5.

Thanks Assaf for nailing it on the head.

The overly dramatic statement “exhibit a massive spike in electricity use beginning at midnight, shooting up to around 4 times the average level” is not needed.

People without EVs have occasional and irregular nighttime usage, that averages to a very low level. And EV owners use 4x as much.

Remember 4×0 = 0
and 4 x minimal = not much

Don’t make a mountain out of this molehill!!

The relatively high usage in NON-EV homes most likely comes from having too many refrigerators and dehumidifiers running, as well as fish tanks, and all those electronic gadgets which never really shut off.

My household consumption last year was about 3500 kwh/year or less than 300 kwh per month on average. This is in a 2200 sq ft house (4 bedroom) with central airconditioning.

13 watt Fluorescents and only 1 large energy star refrigerator puts my rather good sized house more into line with the typical European household, even with the 2 evs.

(And, almost all the other large energy consumers are natural gas – because its cheap in the states – besides its most efficient to use energy in as unmodified a state as possible)

It was a nice start with low electricity consumption but it get spoilled when you say beeing still burning fossil gas. Avoiding fossil fuels is the very first thing to do to green a house. For instance you can use a heat pump for heating or solar collector. In the worst case you can use wood pelets as fuel since it is cycling CO2 instead of adding ever more.

Uh huh…… How much natural gas is used by the “AVERAGE” electric consumer to fire a natural gas fired electric plant versus the little that I use? Currently, I’m making more solar power than I use, so I am powering my neighbors more often than not. My 3500 Kwh/year usage was in the year before, since I just turned up my solar system. Currently, I’m making 3 times the electricity I personally use, but this will change during the wintertime with the short days and the sun low in the sky. In any event, on a yearly basis I will use no utility power at all, statistically speaking.

My natural gas usage is also low by average standards, specifically an average of 85 centum cubic feet per month, and that’s here in very cold Buffalo, New York.

Since you are so ‘green’, tell us what your utility bills are.

Well what you do is good but you could eliminate gas with an heat pump.

For my own utility bill i am in between two houses, the present one which is bad and the new one which is full electric and has essentially no net grid consumption but where i will pay a power availability fee to compensate for the electricity going in at time and out at time.

If you lived where I live you wouldn’t make that statement. Unless the heat pump used geothermal ground water, but the installation cost of that is way way WAY too much for my property.

Perhaps someone in a more rural locale could make use of it, but not where I am.

You may have not investigated heat pumps thoroughly. I am on Lake Ontario and I ditched all my propane two years ago after installing Mitsubishi Mr Slims. I do also have a highly efficient secondary combustion wood burning fireplace insert. Check it out. Your Buffalo location is no reason to assume you must keep burning fossil fuels.

…ps. My dealer told me that last winter was so cold that even geothermal wasn’t cutting it (you have to put all that cold water into the ground and it effectively reduces what is available for heat). His geothermal customers were still kicking in the resistive heating elements. IMHO, better to have carbon neutral secondary combustion wood burning as the option over resistive heating.

Maybe since CO2 is mostly Oxygen we should change from calling it Carbon to Oxygen. Maybe I should drink less water since I want to be ‘Hydrogen Neutral’. 15 years ago everyone was worried about the oceans flooding ‘ by next Tuesday ‘ or other ridiculous claims, meanwhile I’ve just been through the absolutely coldest winter, and so far, a very cool summer. Of course, no one is worried about real environmental problems, such as the recent daily crop dusting of me and my neighbors of Barium, Strontium, and Aluminum Oxide. Thankfully though, Monsanto is an investor in the above program, no doubt so they can sell their ‘Aluminum Resistant Patented Seeds’. Or you west-coasters who recently encounter problems at the WIPP plant in Carlsbad, NM , and not to mention the Pacific Ocean animal die off, or the sardine, salmon, and herring colapse in Alaska, or the caribou die off (27 % last year), or the Polar bear’s Fur falling off, and the dieing cubs. Or dead starfish, or mutated orange crabs that are now blue. Of course, no meterologist mentions this any longer (they used to until they got fired), and no biologist will talk, they just mention… Read more »

Have you looked into the different kinds of geothermal energy + heat pump?

Bill – That may be a magnificent example of low power usage. My EV (super-off peak) usage exceeded 440 kWh alone, last month.

HaHa, its not superefficiency. Its the fact that I bicycle every time I can during the spring, summer and fall.

My EV consumption skyrockets during the winter months, mostly to run the electric heaters.

Actually, from now on since the installation of my solar panels, I’m running the central airconditioner alot more and i’m also driving more during the summer time since now there’s no reason not to.

I project a huge increase in my usage, probably up to 5000 kwh per year (quite an increase from 3500), simply because now I Have no reason to be quite so frugal.

Of course, the more money you have, the more you spend. A local friend here who has ten times the cash I do just built an additional garage for his Tesla Ev’s, with a showroom floor and a natural gas fired hot water heated subfloor to keep both Tesla’s warm during the winter!!!

(He probably uses about as much gas to heat his teslas as I do to heat my house).

Ok Unplugged, I admit ‘ you got me ‘.

I make liberal use of otherwise ‘unused’ free level 2 chargers (especially since I don’t have level 2 at my home anymore due to a nasty electrical inspector).

Have you shared that story? I’d like to avoid “nasty inspector” problems if you have any “lessons learned”.

Its still pending Anon…. Actually, the big money maker for me is the ‘net meter’ we have here in NY State. Theoretically, it is not supposed to be installed until the “town inspector” (in my selfimportant town – most other towns just use an inspection service)APPROVES the installation. O’Connell Electric (a Big electical Contractor in Rochester, NY – 70 miles from here) did the work. I chose a “BIG” contractor for 2 reasons, 1 their price was the best surprisingly, and, 2 they’d have the resources to fight any nasties my fascist town would come up with. A 9120 watt solar system was added to an existing 100 amp service. I do not have a Level 2 charger for either electric car (since the town would have required both a town permit and a town electrician to install it at a really exhorbitant price), and, the other thing is becoming more and more obvious each day, is that I cannot show more loading on this service than on the day I bought the house (previously passed inspection by the town), 3 1/2 years ago. To prove that I don’t use 1 watt more than the existing owner, I’ve offered to… Read more »
I smoozed the local National Grid representative to pull the standard meter and install a ‘net meter’ in its place 2 months ago. So from the billing period even before the solar system was installed to now, I’ve made about $300 of electricity. Now, O’Connell Electric and I signed a contract whereas, with the exception of $1000 earnest money that I’ve already paid, I’m not responsible for any late charges until the Job is completed, defined by passing all inspections. O’connell also will not get paid 80% of the $9120 until they have an inspection certificate from the town. So right now the fight as I see it is between O’connell and the Town. I want O’connell here anytime the inspector is here, since the inspector has already lied to my face and who knows what he might say if it was just my word against his. So, since O’connell was here for the last inspection I want O’connell here for the next inspection, something that i’ve explained is perfectly reasonable. Unfortunately for O’connell, this is rapidly turning into a volunteer job (not much profit for them), seeing as they’re spending much more labor and many more visits to my… Read more »

Just to clarify, the $9120 is dollar a watt ny state ‘NYSERDA’ incentive, and also an $18,080 balance that I’m responsible for When the Job is Completed, (which is not yet). I’ve told O’Connell I’ll pay them the day after they have emailed all the requiste completed inspection certificates to me, which might be a while. So, if they’ve been paid $1000 by me and $1500 by Nyserda, thats less than 10% of the money O’connell is due. So I would think they’d be getting antsy to get the job completed and will bring some form of corporate pressure on my town, a good thing, in my view. Now, as mentioned, I’m not supposed to be selling any electricity at this point, yet I’ve done it for the past 2 months and continue to do it. But the power company is unlikely to go backwards and remove the Net Meter they just installed 6 weeks ago.

I think the night time use of electricity is probably for air-conditioning and or heating.
simple really

A single household average graph of electric use is hogwash. At a minimum, quarterly averages should be compared … seasonal use varies substantially between winter heating months (with short days of light) and summer A/C months (with long daylight hours).

eg: in summer (Jun-Sept) BBQ is used more for cooking, but oven more used in Oct-Jan.

Would be interesting to see how average electric oven use, or electric dryer use compared to average electric car use. (ie: when hourly consumption, use occurs daily)

We (humans) don’t live average lives, so why compare averages? The patterns that are not average are what make living fun! 🙂

Because the average is what the utility sees at their end and thus defines what they need to plan for.

Utilities build capacity to peak and mix to average, and how they do it varies by location, because there’s different usage patterns.

I agree Brian but utilities could well worry about averages so that the US doesn’t experience to much “load shedding” like they do in India or Africa. Maybe not much fun but probably very useful.
but thanks for your thoughts

What would the graph be for gas car owners, if the electricity consumption required for refining the gas they burn was included in the graph?

The graph would be raised by an extra base load since reffineries run 24/7. So their line would start at about the level indicated by the start of the blue line.

You have a refinery in your household? Excuse me, I don’t, I am just one of the regular readers here 😉

Nix was meaning distributed average consumption over all the gasoline users coming from one refinery.

The only thing that makes us “slightly above average” in electricity usage is the plug-in car … we were considerably below average – in the 20% percentile – before. That surprises me; I thought a typical EV owner would generally invest in high efficiency appliances. Unless they’re averaging in EV owners without the TOD rate schedule, or those who do not have L2 chargers …

I find this graph very hard to believe. If I visually try to estimate from this chart, then it seems that EV households exceed regular usage by 50% at least.

And that is plainly not true.

Please weigh in on this, people following this blog with EVs, who ONLY charge at home, did you electricity consumption jump by that much when you started to drive electric? – I claim not

Now, people following this blog with EVs, who OFTEN charge at work, did you electricity consumption jump by that much when you started to drive electric? – Ha ha ha

Been collecting monthly energy data on our 1,800sq. ft. (no A/C) house in SF Bay Area since 1997. Milestones: Got a Ranger EV in early 2000, charge at home 99% of time, drove average 5,000 miles per year. Added 1,000 sq. ft. (and 2nd story) in 2005. Energy efficiency work in 2010. Added Leaf in July, 2011, also drive that 5,000 miles per year (in addition to Ranger EV). Added 6 kW PV system in August, 2012. 12 month kWh averages for each milestone segment: 1997-1999 8,601 kWh (1,800 sq. ft.) 2000-2004 10,073 kWh (added Ranger EV) 2005-2009 12,188 kWh (added 1,000 sq. ft.) 2010-2012 10,399 kWh (energy efficiency work) 2012-2014 4,872 kWh (+PV generated avg. 6,558 kWh) for total avg 11,430 kWh consumed from both PV & grid) NOTE: 2010-2014 data are actually August-July data beginning previous year) Conclusion: Looks like our first EV added about 17% to our annual consumption, and the second EV added about an additional 9% to the annual consumption (plus first EV). Just one household, but real data. BTW, the California Independent System Operator web site (caiso.com) has amazing charts on realtime energy consumption for CA’s 13 million homes and probably 1 million commercial… Read more »

I noticed an electric usage increase of about 50 percent (23.5kWh to 34.2kWh/d) since I got our iMiEV in June last year. We drove just under 10.000mi in the 1st year and all of it was charged at home.

If you drive 15000 miles ev per year, the extra electricity is realistic for a household. But the global picture for all the electricity consumption is an increase of only about 12% if 100% of the cars were to go electric. That is very different because we tend to forget that household electricity consumption is only a part of the global demand.

No, your statement is incorrect. According to http://www.eia.gov/tools/faqs/faq.cfm?id=97&t=3, the average US residential consumer uses 903 kWh per month.Doing 15000 mi in an EV at 4 mi/kWh, adds 312 kWh per month, or a 35% increase.

So if the extreme users increase their usage by 35%, there is no way the average looks like that chart, and this remains true even in every EV owners drives 15000 mi / year.

Lets look again at the anecdotal numbers presented here … 20%, 12%, 19% … then we know the chart is not an accurate representation EV usage in the USA. Period.

My Leaf added about 20% doing about 8000 miles per year.

There’s a bit more detail here:


which also shows some information for EV + PV households. I think it’s when you combine EV and PV that it really gets interesting.

It’s pretty boring actually. No electricity bill to pay, no gasoline bill to pay, very few maintenance issues with the EV, the PV system just sits there and works, no smog checks, no oil changes, etc. 😉

EV +PV is indeed the winning combination that eliminate gasoline use and don’t increase grid electricity use. It should be promoted with an extra incentive on EV car purchase if solar panels are also present or planned.

Thanks for the link to Opower’s research. I read it. if you scroll to the bottom and look at the third chart, it shows “typical households” use 15kWh per day, which is 450kWh per month.

Also the statistics according to Uncle Sam on http://www.eia.gov/tools/faqs/faq.cfm?id=97&t=3 states that the average US residential consumer uses 903kWh per month.

So I figure according to Opower the US does not have any typical households 😉

I do not believe the graph because the morning shower/breakfast spike is not there.

In my house, there is no ‘morning spike’. THe breakfast is cooked with natural gas, and the shower runs on natural gas, unlike electricity which I believe is commonplace in Britain.

In the states by far the most common method for running the ‘morning shower’ is a centralized ‘storage’ autonomous natural gas water heater. Which operates using no mains power at all ever.

Yes indeed the graph seems to have been smooth somewhat.

Looking at KenZ’s link, it would have been more illuminating if they had plotted the EV households with and without solar separately.

It is certainly interesting to find out that on average electric car owners live in bigger homes that use significantly more electricity for non-car uses than non-EV owners.

“electric car owners live in bigger homes”

What an amazing revelation that people who have enough discretionary income to afford a Tesla have above average wealth. Who could have predicted that!

More wealth doesn’t necessitate a larger house with higher energy costs. And not every EV owner buys a Tesla.

LOL Lindsay …

While not every wealthy person has a bigger house than a poor one, on average they do. Really!! And while not every EV owner has a Tesla, many of them do, and it pulls up the average.

And even somebody who buys a Leaf or Volt is above average in wealth.

To sum it up for you …
EV owners (on average) spend more than non-EV owners on vacations, wine, housing, restaurants, clothing, etc, but perhaps not on gasoline.

‘Tis true. Those who can afford an EV and PV likely have enough disposable income. We are guilty of this to be sure; aside from the wife’s obsession with her 1200W hair dryer, we have a musty crawl space and thus have two dehumidfiers, and frankly like our hot tub! Assuaging guilt via a 6kW solar array, which covers that and the wife’s Volt and we have a $500 credit so far this year for electric that we’ll never use up; donated to the grid I guess. Anyway, I digress. The simple fact applies to us: we definitely use more energy than the average home, even though our home is 1200 ft2.

“Assuaging guilt via a 6kW solar array”

too true KenZ, we say quietly to each other, ‘pay it forward’. we still don’t have our EV yet, but it will be covered, based upon our telecommute solar-straight-in vehicle usage, easily.

You are probably more likely to cook on electric induction plates instead of gas as well. EV car ownership goes hand in hand with a tendency to prefer certains systems rather high tech electric than low tech stoves and heaters.

The Y-axis should be in Watts or KW and not kWh. That is because the X-axis is time series.

That pretty much discredits the validity of this graph. I question the motivation of most utilities who from the get go have not been very supportive of EV adoption and have used it as an opportunity to push tiered schemes that benefit them. Throw in Honda and Toyota who have been working with the utilities to throttle and delay charging and the motivation crystallizes.


“…The Y-axis should be in Watts or KW and not kWh…”

Well they weren’t very precise, but perhaps they mean KWH usage during this ‘hour’, in which case you kinda have to look at the graph and ‘listen to what they mean rather than what they say’.

The graph more or less show both what my usage profile was before an electric car, and the other graph after purchasing 2 ev’s, so its accurate enough.

American Power, American Profit, American JOBS.

I realize this is Western US but the electric usage is wickedly low. Looks like an average of 300 kwh a month vs national average of 1000.

In the East, we use a lot of a/c and in some cases a heat pump in the winter. We also heat hot water with electric sometimes – not everyone has NG.

In my area of large homes and a/c requirement, most people use 2000 kwh a month. My neighborhood average is 3000. I bet those curves look a lot different than a Western US house.

Last 30 days 1850 total usage of which 250 EV, -700 PV. So about 15% increase in usage. My net probably has me in the bottom 2-3% for usage and about 30% of my neighbor’s usage.

So EVs around here are a tiny drop in the bucket and at least in the summer would represent less than a 10% increase in usage

36 000 kWh per year? Damn… there is some extreme room for improvement.

An enegry efficiency consultant would make a killing just by taking a 10% cut of the profits for that household of all the improvements he can do.

Unfortunately, no – brick house, under 2k sq/ft, new furnace/AC, new heavy insulation, LED lamps, 10yr or newer appliances, not perfect-but dual-pane windows and storms, new energy-efficient fiberglass entry-doors, new roof. Utility bill dropped only 20%, located in upper midwest.
We’re retiring under 10y, we Need those numbers to improve and Spent to do so, not thrilled with the performance to dollars, me.
Haven’t done the payoff math, cuz it doesn’t look like I need to, heheh. The solar is the only thing that may have a chance of paying us back.

EVs should not charge on the evening peak. After suppertime they could start charging on randomized intervals to level the cumulative load curve. This will be a great boon to utilities and customers cuz a flatter load curve means cheaper electricity in the long run – less idle capacity to pay capital costs for.

Totally agree, but that needs to be (and likely eventually will be) driven by the price incentives given by the utilities. For us, our utility drops to the lowest tier at 9pm, so that’s when our car is programmed to start charging, simple as that. Would clearly make more sense to be able to have it programmed to start at midnight, or better yet, have it start as late as possible to still achieve full charge by your set time, such as 6:30 am for us. In our case, that would mean a charge starting around 3am, which would clearly be better for the grid than 9pm. But as far as I know, our volt doesn’t have that capability to start charging to achieve a complete charge by a certain time, only the ability to set the start time.

Yes I understand your point. Only trying to suggest that easily programmable random charging in off peak intervals will be a good thing in the future as more EVs come on line. Peaks are only a load concern really at temperature extremes say below 20 or above 90. But leveling the load curve at all times on every day allows utilities to keep the most efficient generators on line – which will save all of us money. People that have them run the nukes all the time to take advantage of the low fuel cost once a unit is up and running. Nukes and EVs promise a bright energy future.

There could be a benefit to random starts, but many people (or maybe just me) don’t trust turning that over to the system. Where I am I don’t have time of use pricing, so unless I’m playing around with it for fun it’s always set to charge immediately after plug in. Depending on how much driving I had to do on that day it could be full be for I head off to sleep, before midnight. What I can’t abide is the fear of finding out it didn’t fully charge (or at all) by the morning because the system started me too late.

I have a 2011 Volt and charge this way every day. Check out your owner’s manual…

You have 3 choices on the center console:

1. Immediate charge

2. Charge by utility rate and departure time

3. Charge by departure time

All you need to do is go into the configuration screen and setup the departure time for each day of the week. Mine is set for 6am so it starts charging around 2am and completes around 5:45am when I need to charge from an empty battery.

I have TUO for my house and the increase for charging is not that big (charger timer set for midnight to 2 or 3 am). Here is my usage for the last few months: