Electricity Costs in Massachusetts/New England

So, while I was getting ready to figure out overall costs before ordering the Model S, I developed a spreadsheet to track all costs (now and anticipated). I may not be a prime contributor to your question as I don't actually have a Model S and I also have 8.4 kw of solar panels on my roof, however, I figured I would toss in my 2 cents. I've been asked if solar is worth it. The answer: absolutely!

I have a "grid interactive" system that uses batteries (much bigger then the Model S). So I had to do a lot of math to determine my run time and other battery metrics (like bulk, float and absorb charge settings). There's is MUCH more to charging batteries then just throwing some juice at them. I also have to keep accurate records so I get paid to make the power (I get paid whether I use it or not thanks to SREC credits).

I've developed a pretty good nack for getting really close to actuals, so... In calculating my costs I computed it by taking the anticipated mileage and dividing it by the 220v 40A recharge rate on the website. The math is as follows:

220 (volts) x 40 (amps) = 8800 watts or 8.8 kw. If I draw 8.8 kw for 1 hour that's 8.8 kwh.

If I drive 800 miles/month @ the 29 miles per hour charge rate, I would theoretically take 27.6 hours/month to charge the car not assuming the inefficiencies (I would draw 242.8 kwh/month). You might think that reduced charge rates as it tops off the batteries would play into this, however, it really does not.

If a kwh would cost $0.13632 I would multiply that by the 242.8 to come up with $33.10/month.

Now to directly answer your question, the highest I paid for power is $.16786/kwh and lowest would be $.14516 (WMECO) this is largely due to a higher cost for using more power then the "average home". Yeah, right! In case anyone was considering getting solar, my effective high kwh cost is $.15140/kwh after solar offset and my lowest is $.01015/kwh.

I concluded that, based upon last years power costs and mileage, my lowest cost would be around $2 and the highest would be around $37. I would say that it is MUCH better then the $200+ I spent in gas.

Andy

My rate is $.0819 generation and $.0747 distribution.

Take miles driven and divide by 3 to get a reasonable approximation of kWh. So if you drive 12,000 miles a year, it would be 4,000kWh or $626 at my electric rates in CT. If you expect to use a supercharger, you can deduct the miles that you will replenish there.

By comparison, my Prius gets 48mpg and gas costs about $3.80 a gallon. That same 12,000 miles in my Prius would cost me $950 in fuel. My Acura at 21mpg (more comparable to the MS) would cost me $2,171.

Wow I could swear I was paying .17 here.. I'll have to check my bill.
That said, when I moved to my sister's place for 6 months in the summer, her electric bill increased by $160 -- $40 of which was my A/C and other "me" stuff.. So $120/mo for a 76 mile/day commute, plus whatever other driving I did which was probably another 150 miles a week.
We do have TOU rates here from what I understand but when I went to see about implementing that at my house, I chose not to incur the additional capital expense (vs. just increasing my service to 200 amps). Plus my commute is 8 miles a day now

I'm at about .15/KWH, the simplest way is to just take your entire bill and divide it by the total KWH consumed, that factors in the customer charge, taxes, and all of the "other fees" you have to pay. My bill went up $35/month, but that's when I had a 35 mile roundtrip commute to downtown Boston, now my commute is just 10 miles roundtrip, so even less per month with the new job

Ben, you going to update your location?

I'm $0.167/kWh based on my last bill (excluding the static $7/mo "customer charge"). MassX -- who's your energy supplier? Are you signed up for any special rates? Your rate's awfully high (for this area) ...

mitch672 said:

Ben, you going to update your location?

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Oops! So many places to update my location ...

I have every bill since 2006 entered into a spreadsheet.
In July 2011 I got solar panels installed and in early January 2013 I took delivery of my Model S.
I've gone from a low of $0.141/kWh to $0.21/kWh, thanks to fracking I'm paying about $0.17/kWh
for the past 3 years.

From 2006-2010 (no solar) I averaged $2177/year
2011 is not counted because I have solar part of the year.
In 2012 (pre-Tesla but with solar panels) I payed $510 for electricity.
In 2012 (Tesla + solar) I paid $1498 for electricity. If the delta is completely attributable
to my car that is about $988.

I drove almost 21,000 miles in 2013 Around July I got access to a charger at work (I still charge at home).

If I was paying about $60/week for gas and driving about the same mileage (I have a 30 mile commute one-way
among other things). $60/week * 52 weeks is over $3k...


year billing days cost/year average rate/year comments
2006 360 $2,326.27 18.75 cents/kWh
2007 371 $2,545.94 18.20
2008 364 $2,101.25 19.19
2009 365 $2,115.46 19.05
2010 369 $1,796.56 16.61 Start of the fracking???
2011 363 $1,430.24 16.61 partial solar
2012 366 $510.41 16.91 solar whole year, no Tesla
2013 366 $1,498.40 16.69 Tesla shows up in early January!!!

Also note that when comparing to other performance cars, you'd be using premium gas, not regular.

cinergi said:

Also note that when comparing to other performance cars, you'd be using premium gas, not regular.

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Correct, I was coming from a minivan which got about 22MPG but took regular.

EdA said:

I have every bill since 2006 entered into a spreadsheet.
In July 2011 I got solar panels installed and in early January 2013 I took delivery of my Model S.
....

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That savings from solar is quite nice... how much PV did you install?

I pay roughly $0.16pkwh with NStar, and I drive about 2000 miles/mo. With my previous ICE, I spent about $500/mo on gas (17mpg @ $4/gl premium). Now, with my TS I spend about $100/mo in extra electricity... So my fuel cost is now about 20% of what I used to spend on gas!

772 said:

That savings from solar is quite nice... how much PV did you install?

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It is an 8.2kW system (36 panels, 225W/panel).

Note: I have a 4BR house with 2 fridges and 2 dehumidifiers and central air...pretty much all the fixings.

@EdA, have you determined what you're actually paying for electricity? 8.4 kw here.

andydoty said:

@EdA, have you determined what you're actually paying for electricity? 8.4 kw here.

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Not sure I get your question, do you mean the effective rate I'm paying? Haven't calculated it.

The difficulty is comparing like-to-like. If you bicycled everywhere before, then your transportation fuel cost is going to go up quite a lot! The Model S is comparable to an Audi S7, which gets a combined 20 mpg on premium fuel.

It takes 30kWh to travel 100 miles in the Model S; at $0.21/kWh, that's $6.30.
It takes 5 gallons of premium fuel to travel 100 miles in an Audi S7; at $3.57/gal, that's $17.85.

So I see the Model as costing roughly 1/3 in fuel costs relative to a comparable gas-fueled car. If you compare it to a Prius or a minivan, you're not fully accounting for the step up in the vehicle class. A villa in St. Moritz costs more to maintain than a two-bedroom in Melrose, but you can't put down the entire cost difference to the prices in St. Moritz.

I have a dedicated 240v line with meter for my charger because we have a shared garage in our small condo. Got the car in early March, meter two months later due to various delays.

My effective rate including sales tax and other charges is 15.2 cents/kwh, and my consumption has ranged from 338 kwh to 633 in a month when I made multiple long distance trips, usually I'm in the low 400s. So the monthly bill has ranged from $50 to $100 but is generally in the $55-65 range. In the first 10 months I put 12,000 miles on the car. I went from a 2011 Audi A4 which I was filling up 2-3x per month at about $45-50 per fill up (premium fuel). But I am putting about twice as many miles on the Model S, because with its greater people and luggage capacity than the A4 I take it on many trips that previously would have required our minivan. I haven't checked, but the minivan's mileage and fuel consumption have likely dropped considerably. And if we get a few more superchargers in places like Sturbridge MA, Albany NY, West Lebanon NH and in Maine it will drop even further.

You folks are giving me some perspective on what I pay.

For the month of December, 2013, I consumed 1480 kWh and paid $253.78 (based on the town power plant's data). That's $0.1715/kWh.

But.... that includes a "residential renewable 100%" fee that I also pay, at the behest of my wife, for the power company to invest in renewable energy to offset the non-renewables we are using in their power mix. That was $59.20 for December. Subtracting that back out, I'm down to $0.1315/kWh.

There's a step function hidden in the formula, where the company charges a penny or so more per kWh each time I hit a break -- at 401 kWH, 1001 kWh, and so on. The numbers I've quoted above are the totals on the bill.

I'm at 360 wh/mi over 8000 lifetime miles. I compare against a hypothetical luxury sedan @ 25mpg (a generous estimate!) and premium gas @ $4/gal, and figure I'm paying somewhere around 30-40% of what I'd pay for gas, depending on how efficiently I'm driving and whether I factor out the residential renewable charge. Of course, I would have also changed the oil once or twice by now in a comparable ICE, and probably done those changes at the dealer rather than Jiffy Lube, and the dealer probably would have charged me dealer rates rather than just giving me those oil changes and oil for free. So a few more dollars of hypothetical savings chalked up.

Alan

cinergi said:

Oops! So many places to update my location ...

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I updated my location as well, since I'm hardly ever in Boston any longer (and have a much better commute now)