Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.
Register

Lifetime Energy Consumption for my Model S in Boston Area after 4 years

Gene_nos

Member
Jun 6, 2020
12
0
New Zealand
Last week was the 4th anniversary of the activation of my home charging set-up at my condo, so I thought it would be interesting to see how much energy I had purchased from our local utility, Eversource. (I live in eastern Massachusetts.)

I charge the car (a 2015 70D) with a Tesla Wall Connector connected to a 240 Volts single-phase 50-amp circuit. The cable run from the meter to the Wall Connector is roughly 25 feet. I usually charge at 40 amps.

There is a separate service and electric meter for charging my car, so it is (almost) easy to see how much energy the car consumed. I say “almost” because there was a brief gap in my data for which I made an adjustment. Plus, I have a motion-activated security lamp on the same service. The lamp does not run for very long when it activates, so I decided to ignore the lamp’s energy use, as it would be very small compared to the car’s.

In those four years, the circuit consumed 17,827 kWh, while the car went 41,033 miles. So, based upon these raw numbers, we could say that the car charging (including charging losses plus precooling and preheating) consumed an average of 348.7 kWh/mile driven. That compares to the lifetime average consumption shown by the car in July 2019 as 326 Wh/mile. (I lost my historical data at that time because of a computer repair.)

Unfortunately, that is an incomplete picture, because it does not allow for charging elsewhere, such as use of Superchargers and destination chargers on trips. I do not have very good records of charging away from home. So, I made an estimate of the mileage driven away from home over those four years and decided to allow 1,000 miles per year as a rough but reasonable allowance. So that means the Eversource energy was used for about 37,033 miles. The average energy use then looks like 481 Wh/mile, a much higher figure, and a bit startling. I know that charging losses have been estimated at 10% or so, but this would be quite a bit higher.

Most likely, the largest source of extra consumption is preheating and precooling the car. I tend to use that function quite a lot, because my car is parked outside, winter and summer. The car does not consider the energy used for that in the displayed energy consumption, when the car is connected to shore power. Since the car's heater can operate at as much as 6 kW, prolonged use of preheating in winter can add considerably to total energy consumption. Air conditioning does not consume as much, but even that does add something to energy costs.

At my current average price per kWh of about 23 cents, that translates to approximately 11 cents per mile for energy. That is not much if any savings compared to my previous car, which was a Mercedes that got about 20-23 mpg on premium fuel. Which I why I tell people around here that they should not buy a Tesla, or any other EV, with the goal of saving on energy. (The exception might be if they happen to live in a town or city with a municipal electric department, which typically provides energy at a much lower cost.)

My numbers do contain some assumptions, the most important of which is my allowance of 1000 miles per year for travel charged elsewhere. That may be conservative, and I hope it is, but it is not too far off. In any case, it is worthwhile to realize that charging losses may add to the energy consumption reported by the car. And in my case, preheating and precooling probably contribute substantially to the actual total energy used and the cost of it.

One other point: The precooling and preheating would be a smaller factor in cost per mile if I drove more. But I am retired, so I do not commute. And of course, since mid-March we have been driving very little because of the Covid-19 shutdown.
I love the data - I live in New Zealand and my kWh from my utility is only 16cents (in $nz) which is 10cents $US and my utility gives 1 free off peak hour a day which is 7.5kwh into my 2015 MS Which covers all my usual daily drives - last month with any number of free destination charges and free public chargers I came in at 2.9cents ($NZ) ($US 2cents) a km for the 3321km I drove - in my old Subaru (gas/petrol) is expensive here I was 20cents ($NZ) (13US cents) a km so I’m getting big savings -
 

Les236

Member
Jan 20, 2018
223
104
Kissimmee, FL, Boston, MA
BTW I was just contacted by national grid to join a program to plug in a device to the car so they can better understand EV charging. I hope they are planning TOU billing as they charge .27 kWh now. Program name is SmartCharge.
I signed up for that yesterday as well, and requested the free "Y" cable so I can continue using my own app to monitor my MX. Turns out they also have the same program in Florida, but I signed up for the one in MA since I think I'll be there more.
 

Les236

Member
Jan 20, 2018
223
104
Kissimmee, FL, Boston, MA
I don't know any North American (not in Hawaii or Alaska), that pays $0.23 per kWh for electricity! You are getting ripped off by your utility/wholesalers who must have invested in the wrong energy sources or are regulated by a corrupt utility commission! Electricity should be falling in price in the coming years with cheaper solar and wind steadily increasing and expensive coal falling out of the mix. Maybe you are helping fund inefficient nuclear plants too. I would definitely look into roof top solar because the payback period would be very short (probably less than 10 years)!
My town in MA negotiated a slightly lower rate for the electricity, although we still pay national grid for the lines and distribution. Our rate fluctuates monthly, but averages right around $0.23/Kwh as well. Definitely planning on putting solar there first. Electricity is high in MA. My daughter whose town has their own power company is even higher.
 
  • Helpful
Reactions: StealthP3D

65sc02

Member
May 23, 2019
7
4
Germany
In those four years, the circuit consumed 17,827 kWh, while the car went 41,033 miles. So, based upon these raw numbers, we could say that the car charging (including charging losses plus precooling and preheating) consumed an average of 348.7 kWh/mile driven. That compares to the lifetime average consumption shown by the car in July 2019 as 326 Wh/mile. (I lost my historical data at that time because of a computer repair.)

How do you get to "an average of 348.7 kWh/mile driven"? I guess you mean 348Wh/mile. But even this number seems off:
17,827 kWh / 41,033 miles = 434Wh/mile
 

X-treme

New Member
Aug 25, 2020
2
2
CT
Last week was the 4th anniversary of the activation of my home charging set-up at my condo, so I thought it would be interesting to see how much energy I had purchased from our local utility, Eversource. (I live in eastern Massachusetts.)

I charge the car (a 2015 70D) with a Tesla Wall Connector connected to a 240 Volts single-phase 50-amp circuit. The cable run from the meter to the Wall Connector is roughly 25 feet. I usually charge at 40 amps.

There is a separate service and electric meter for charging my car, so it is (almost) easy to see how much energy the car consumed. I say “almost” because there was a brief gap in my data for which I made an adjustment. Plus, I have a motion-activated security lamp on the same service. The lamp does not run for very long when it activates, so I decided to ignore the lamp’s energy use, as it would be very small compared to the car’s.

In those four years, the circuit consumed 17,827 kWh, while the car went 41,033 miles. So, based upon these raw numbers, we could say that the car charging (including charging losses plus precooling and preheating) consumed an average of 348.7 kWh/mile driven. That compares to the lifetime average consumption shown by the car in July 2019 as 326 Wh/mile. (I lost my historical data at that time because of a computer repair.)

Unfortunately, that is an incomplete picture, because it does not allow for charging elsewhere, such as use of Superchargers and destination chargers on trips. I do not have very good records of charging away from home. So, I made an estimate of the mileage driven away from home over those four years and decided to allow 1,000 miles per year as a rough but reasonable allowance. So that means the Eversource energy was used for about 37,033 miles. The average energy use then looks like 481 Wh/mile, a much higher figure, and a bit startling. I know that charging losses have been estimated at 10% or so, but this would be quite a bit higher.

Most likely, the largest source of extra consumption is preheating and precooling the car. I tend to use that function quite a lot, because my car is parked outside, winter and summer. The car does not consider the energy used for that in the displayed energy consumption, when the car is connected to shore power. Since the car's heater can operate at as much as 6 kW, prolonged use of preheating in winter can add considerably to total energy consumption. Air conditioning does not consume as much, but even that does add something to energy costs.

At my current average price per kWh of about 23 cents, that translates to approximately 11 cents per mile for energy. That is not much if any savings compared to my previous car, which was a Mercedes that got about 20-23 mpg on premium fuel. Which I why I tell people around here that they should not buy a Tesla, or any other EV, with the goal of saving on energy. (The exception might be if they happen to live in a town or city with a municipal electric department, which typically provides energy at a much lower cost.)

My numbers do contain some assumptions, the most important of which is my allowance of 1000 miles per year for travel charged elsewhere. That may be conservative, and I hope it is, but it is not too far off. In any case, it is worthwhile to realize that charging losses may add to the energy consumption reported by the car. And in my case, preheating and precooling probably contribute substantially to the actual total energy used and the cost of it.

One other point: The precooling and preheating would be a smaller factor in cost per mile if I drove more. But I am retired, so I do not commute. And of course, since mid-March we have been driving very little because of the Covid-19 shutdown.

I also have Eversource in Northern CT and here are my figures after a few months of ownership.

From Eversource...
Eversource’s residential standard service customers will see their generation rate drop from 9.41 cents per kilowatt hour to 7.38 cents per kilowatt hour, according to Mitch Gross, a spokesman for the company
The standard service generation rates change twice a year, on Jan. 1 and July 1.

So, here are my calculations @ 20 cents / KW (includes delivery charge)

Electric 333 Wh / mile (w/ AC) = 3 miles per KW or 7-cents per mile

Electric 250 Wh / mile (w/o AC) = 4 miles per KW or 5-cents per mile

Gas @ $3 per gallon and 21 miles per gallon = 14-cents per mile

Gas @ $2.50 per gallon and 25 miles per gallon = 10-cents per mile
 
  • Informative
Reactions: David29

tga

Supporting Member
Apr 8, 2014
3,953
2,796
New Hampshire
My town in MA negotiated a slightly lower rate for the electricity, although we still pay national grid for the lines and distribution. Our rate fluctuates monthly, but averages right around $0.23/Kwh as well. Definitely planning on putting solar there first. Electricity is high in MA. My daughter whose town has their own power company is even higher.
5 years ago, Hudson Light and Power charged Hudson and Stow residents $0.14/kWh, and paid $0.05/kWh for excess solar generation (munis are not required to net meter, so they paid their wholesale rate).

With my new TOU rates (see here and here), I current pay $0.085/kWh to charge (summer, nights). At ~360kWh/mile, that's 3 cents/kWh. I have free lifetime supercharging, and about half of my miles are roadtrips, so I easily pay less than 2 cents/mile.

I'm lucky to get 10k miles off a set of rear tires (~$450 for Falken Azenis FK510) and twice that on the fronts. So 450*3/20000=$0.0675/mile for tires. The "official" tire is almost double that (Pilot Sports).

When people ask about how much it costs to run the car, I tell them I pay more in tires than fuel. If they want to drill down, I share the math.
 

Garyranderson

Member
Jul 10, 2020
15
6
Chicago
247?? Amazing. My May 2017 S D100 had a lifetime of 316 at 42000 mi. I thought that was pretty good given all the cross country I have done. Many of those miles were in mountains and at 80 mph when that was the speed limit.

I lost the data when I upgraded the MCU a few weeks ago. So now starting the meter over.

But 247? My car is rated at 300... so until now I felt 316 was decent.

I over produce with solar. So charging the car cost 3 cents a kWh, the price the power company pays me for the extra. A good deal for them since they sell it for 19-35 cents....

I was thinking of getting the bumper sticker: my car runs on sunshine.... when I am home... :)
That's the chief reason for my not buying solar panels. They sell me energy at premium prices, add in a "delivery and administration charge" and if I overproduce they pay me discounted rates, --so they can turn around and sell that energy again to someone else for the premium rate. I don't even get to charge them any delivery or administration fee! If my panels age or break, it comes out of my pocket. I wonder what Elon Musk would say about this.
 

Garyranderson

Member
Jul 10, 2020
15
6
Chicago
I also have Eversource in Northern CT and here are my figures after a few months of ownership.

From Eversource...
Eversource’s residential standard service customers will see their generation rate drop from 9.41 cents per kilowatt hour to 7.38 cents per kilowatt hour, according to Mitch Gross, a spokesman for the company
The standard service generation rates change twice a year, on Jan. 1 and July 1.

So, here are my calculations @ 20 cents / KW (includes delivery charge)

Electric 333 Wh / mile (w/ AC) = 3 miles per KW or 7-cents per mile

Electric 250 Wh / mile (w/o AC) = 4 miles per KW or 5-cents per mile

Gas @ $3 per gallon and 21 miles per gallon = 14-cents per mile

Gas @ $2.50 per gallon and 25 miles per gallon = 10-cents per mile
Those are GREAT numbers!!! But, don't forget, --as soon as EV's become predominant, our friends will outlaw home charging on the home circuit, and add a new power generation tax, and then add the roaduse taxes that all the ICE cars have to pay. Walking is still FREE!
 

ArcticStation

Supporting Member
Oct 10, 2018
175
262
Maine
You are getting ripped off by your utility/wholesalers who must have invested in the wrong energy sources or are regulated by a corrupt utility commission!

Yup. In Maine, we are so fed up with the cost of electricity (approaching $0.20 per KWH) and lack of customer support (one utility rated “the worst in America” by J.D. Power), there is an initiative by some of our state legislators to buy out the foreign owned utilities that currently supply our power and create a publicly owned utility serving the entire state.

We are a state of around 1.4 million facing an estimated acquisition cost north of one billion bucks, so it is a big deal. But more and more of us are becoming convinced that it would make a lot of sense to maintain oversight of our utilities by the new owners (us) and keep any profit within the state, rather than see it go to stock holders living in foreign countries.
 

StanT

Member
Jan 23, 2020
148
185
Fishkill
So here is the Hudson Valley NY- delivery plus supply and all the other crazy fees... $0.185/kWh This does include the $20/month just to have a meter and be connected.
2020-09-05_21-49-24.jpg
 

nomis_nehc

Member
Jul 9, 2018
207
153
Rancho Cucamonga
I

I don't know any North American (not in Hawaii or Alaska), that pays $0.23 per kWh for electricity! You are getting ripped off by your utility/wholesalers who must have invested in the wrong energy sources or are regulated by a corrupt utility commission!

Haha. You clearly are not familiar with the rates here in CA...
 

StealthP3D

Well-Known Member
Dec 12, 2018
9,408
73,455
Maple Falls, WA
That's the chief reason for my not buying solar panels. They sell me energy at premium prices, add in a "delivery and administration charge" and if I overproduce they pay me discounted rates, --so they can turn around and sell that energy again to someone else for the premium rate. I don't even get to charge them any delivery or administration fee!

While the rules need to be updated to favor the consumer rather than the utility, your chief reason for not getting solar panels is not sound or logical. What matters is the bottom line.

When your panels are producing enough to meet your needs, you are not having to pay the utility the "premium prices" for delivery OR anything for production. And when they are producing more electricity than you need, you still get some return on your investment.

The key metric is years to break-even. Because after that it's all gravy. If you want to take it a step further, a Powerwall will allow you to use electricity at night that you have produced during the day. That may not have a reasonable return on your investment in your case but for many it could. Rooftop solar has a positive return on investment for most while battery storage only does for a minority of utilities and situations.
 

David29

Supporting Member
Aug 1, 2015
2,237
1,877
DEDHAM, MA
How do you get to "an average of 348.7 kWh/mile driven"? I guess you mean 348Wh/mile. But even this number seems off:
17,827 kWh / 41,033 miles = 434Wh/mile

Oh, sorry, yes, referring to "kWh/mile" was a stupid error in units, my apologies.

As to the numerical value itself, I see I made another error -- it is 17,827 kWh divided by the mileage over four years, but I used the wrong figure. I should have 41,033 miles as the miles driven in that four years. So as you calculated, the correct value would be 434.5 Wh/mile. My sincere apologies! And thank you for catching the error.

The adjusted value, allowing for Supercharging, was correct at 481.4. So, the difference between 481 and 434 is less dramatic. That difference of 50 Wh/mile accounts for the losses in the charging system as well as consumption of energy for preheating and cooling, but remains an estimate.

Thanks again for catching my math errors!
 

David29

Supporting Member
Aug 1, 2015
2,237
1,877
DEDHAM, MA
Hi David -

Is the purpose of the separate service to get a special rate from your Utility? Not sure whom it is, but I know even National Grid (which I have in Buffalo, which charges, including taxes and fees, about 12 cents per kwh after around $18 for the billing charge) charges much more in New England - supposedly since all your electricity generation in the area is high-cost.

If this is a 'discounted' rate - how much is the non-ev electric service? Around my parts, those rates would be considered confiscatory.

The separate meter was a necessity because of the location of my car's parking space in my condo parking lot, quite a distance from my own building. So $7 of my monthly cost is the fee for that service, which most people would not need to pay if there car charging is on their home's service. That does add an average of about 2 cents per kWh to my average cost.

My utility is Eversource. I do not get any special rate for having an EV. The only discount rate Eversource is offering now requires purchase and use of an EV charging device that can be connected to the internet (via WiFi) so that Eversource can use it to manage load in times of high demand. My son has it for his plug-in hybrid. He happened to already have a WiFi-enabled meter (from ChargePoint), so there was no added cost for him to join the Eversource program. But in my case, I would need to buy the charging device, and i do not think the small savings would offset the added cost for some time. Plus, my WiFi barely reaches the car and is unreliable at that distance, so it might not work anyway.

Eversource did offer a Time of Use Rate when I first had the car, and that did save me about 10%. But they discontinued that rate in their last rate adjustment, to my annoyance.

I do have a small discount because my entire town is using a "community aggregation" service to purchase energy wholesale from a supplier instead of using the Eversource default suppliers. I have tracked the savings over the past four years, and they amount to about $100 per year for the condo and house together.
 

Bill25cycle

Member
Mar 31, 2011
103
69
So here is the Hudson Valley NY- delivery plus supply and all the other crazy fees... $0.185/kWh This does include the $20/month just to have a meter and be connected.
View attachment 584941

oK, so your marginal cost (ignoring the $20/month billing charge) is $0.153 (15 1/3) cents per kwh. Considering you live in downstate NY state, that is really not too bad. In Western NY (buffalo), I pay about 12-13 cents per kwh, (my true marginal cost including taxes), ignoring the $18.06 (billing charge and taxes) that everyone has to pay.

You should see how Con ED rapes Westchester County and NYC customers. Its more than double what you are paying now.
 

Bill25cycle

Member
Mar 31, 2011
103
69
The separate meter was a necessity because of the location of my car's parking space in my condo parking lot, quite a distance from my own building. So $7 of my monthly cost is the fee for that service, which most people would not need to pay if there car charging is on their home's service. That does add an average of about 2 cents per kWh to my average cost.

My utility is Eversource. I do not get any special rate for having an EV. The only discount rate Eversource is offering now requires purchase and use of an EV charging device that can be connected to the internet (via WiFi) so that Eversource can use it to manage load in times of high demand. My son has it for his plug-in hybrid. He happened to already have a WiFi-enabled meter (from ChargePoint), so there was no added cost for him to join the Eversource program. But in my case, I would need to buy the charging device, and i do not think the small savings would offset the added cost for some time. Plus, my WiFi barely reaches the car and is unreliable at that distance, so it might not work anyway.

Eversource did offer a Time of Use Rate when I first had the car, and that did save me about 10%. But they discontinued that rate in their last rate adjustment, to my annoyance.

I do have a small discount because my entire town is using a "community aggregation" service to purchase energy wholesale from a supplier instead of using the Eversource default suppliers. I have tracked the savings over the past four years, and they amount to about $100 per year for the condo and house together.


That's not such a bad deal... In my state - such an arrangement would be at commercial rates (non-demand since under 2000 kwh/month), and would be about 14 cents/ kwh plus a $25 billing charge. That is the non-residential rate here, which you'd have to pay since you don't live in that space. Residential rates are 12-13 cents plus a $18.06 billing charge (all taxes included).
 

About Us

Formed in 2006, Tesla Motors Club (TMC) was the first independent online Tesla community. Today it remains the largest and most dynamic community of Tesla enthusiasts. Learn more.

Do you value your experience at TMC? Consider becoming a Supporting Member of Tesla Motors Club. As a thank you for your contribution, you'll get nearly no ads in the Community and Groups sections. Additional perks are available depending on the level of contribution. Please visit the Account Upgrades page for more details.


SUPPORT TMC
Top