smoke and mirrors

My friend Ken gave me a ride in his new Tesla (model Y (1)). the other day.  Pretty fine car: beautiful deep blue, sleek clean lines, simple spacious interior, and plenty of power (though Ken says those surges are tough on the battery).  Ken’s position as a UCSD professor places him square in the service class of La Jolla but with enough dough to keep him in nice cars.  He says his Tesla was cheaper than his previous ride, a Beemer.  Of course, he enjoys driving right by those $6/gallon California gas stations.  Ken’s a lib, but not a mouthy one, so of course he gains satisfaction from his low carbon footprint. This week, the temp in LJ has not crept past 65 and the sun is rare, so we could use a little global warming around here, but it’s not coming from the likes of Ken.

Or is it?  I remember Rush (God rest his soul) calling electric cars “coal-fired”.  Although such cars don’t even have tailpipes, the energy that powers them comes from generators that have to burn something to make that electricity.  I’ve wanted to get into the nitty-gritty of how those putt-putt plug-ins are powered, and Ken’s Tesla provided the impetus.  So here’s what I found out about the costs and consequences of this ever more popular way of driving.

Fueling up

The full recommended charge for a Tesla on a home unit (which Ken paid $2500 to install) goes as follows.   The home unit provides 240 Volt, 80 amps of current.  This charges a Tesla much faster than the 20 amp 120-volt charger.  With a 240-volt connection, you can charge a Tesla Model Y completely in between 6 and 30 hours. The 240-volt charger adds between 9 and 52 miles of range per hour of charging.   Power companies charge per kilowatt-hour.  Watts=voltage X current (amps).   An installed 240 volt Tesla home charger running at max uses 19,200 watts, or 19.2 kilowatts.  Running that puppy the 6-30 hours it takes to fully charge a Tesla will then consume 115.2 – 576 kilowatt-hours.

San Diego has the highest electricity rates in the country (2), but few actually pay them.  Residents have 3 tiers of rates depending on time of day, with “off-peak” 9-midnight and “super off peak” midnight to 2 PM.   So you plug in as late as possible.   Standard residential rate is $0.39206/kw-h.  So that “fill-up” will cost ya $45.17 – $225.83 in San Diego.  My Michigan rate from DTE is $0.041760/kw-h, so my costs will be less than a 10th what I’d pay in LJ.  And our gas is only ~25% cheaper.   Per the Tesla web site, the Model S gets 396 miles on a full charge, which comes to 11.4¢ – $1.754/mile.  To compare, my rickety but beloved ’11 Jeep Patriot gets ~18 mpg, so with the $4.20/gallon Michigan gas that’s 4.29¢/mile.  Even with California gas, I think you can see the vinner here.  Plus, my Patriot was paid for long ago and I don’t even want to think about Ken’s car note.

San Diego Gas & Electric offers 3 special packages for electric car owners (2).  The best deal, at least as regards base rates, for a mere $16 month will lower your charges to 66¢/40¢/11¢ for basic, off-peak, and super off-peak.  So you still have to wait till 9 PM to plug in to even get close to the standard rate.

But there’s other ways to juice up your Tesla.  Virtue-signalling municipal governments everywhere have thrown up “free” charging stations (guess who’s paying for the juice?).  Where’s my free gas pump?  But such stations are ever less useful as more embrace electric cars and demand for those plugs expands.  The short charge is never more than a top-off.  Commercial charging stations have popped up all over in Southern California (4), but are already overtaxed.  Ken keeps a map of all the charging stations in the region, but as the market for juice remains fluid, stations come and go.

Tesla has its own changing stations which promise to add 200 miles in 15 minutes.  For commercial and municipal charging, they recommend carrying around a couple adapters in your trunk (5).  Commercial chargers do not yet have uniform fee schedules, but are moving from charging by time plugged to charging per unit of energy.  Right now, drivers in California can expect to pay 30 cents per kWh to charge on Level 2, and 40 cents per kWh for DC fast charging.  So that’s a little higher than what they’d pay at home.  And way higher than what I’d pay in my home state of Michigan, where electric car drivers pay 17¢/kWh (6).

But electric cars were never touted for their economy.  Uncle still subsidizes every electric car purchase with a tax credit that starts at $2500 and can reach $7500 (7).  As it’s usually the upper crust that buys these things, this sure ain’t addressing “income inequality”.  Of course, California signals its virtue by offering an additional $1000-$7000 per electric vehicle bought or leased, although they no longer offer that for a Tesla purchase (8).  In Michigan, our Governor Bimbo has proposed a $2000/car rebate plus $500 for a home charging station (9).  Fortunately her January proposal has gone nowhere in our Republican led congress.

Whatever the rebate, these electric cars are way more expensive than your trusty gas guzzler.  But you can’t put a price on the warm and fuzzy feeling you get by signalling your virtue.  Getting behind the wheel of one of these means you’re doing your part to push back the climate catastrophe our betters are always telling us is barely 10 years away.

But are you really?  For the sake of argument, at least for the rest of this post, let’s assume that CO2 emissions actually do influence climate and maybe it’s a good thing to reduce them.  Does driving an electric car further those ends?  Remember, those kilowatt-hours have to come from someplace, and I’ve yet to see an electric car bearing solar panels.

Ken’s source of juice, San Diego Gas and Electric, prides itself on its “clean” profile.  They claim to derive 40% of their generation from “renewable” resources, wind, solar, and likely a bunch of hydroelectric.  Plus they boast they have no active coal contracts.  Whether there are some power plants with big paid-for piles of the black stuff outside, they don’t say.  They are obligated by law to report their emissions, although the latest year covered on their web site is 2011.  No telling what their fuel mix was then, but they put out 1,266,649 metric tons of CO2 as direct emissions and an additional 299,785 tons in indirect emissions (10).  Once I’ve burned up the 6 cords of firewood out front of my house, I’ll have contributed 15 tons of CO2 to our climactic demise (11).  But then, I’m not working to keep the lights of millions on.

To do that, for its 4,327 industrial customers, 104,875 commercial accounts, 4 transportation customers and 1,287,811 residential customers,  SDG&E generates 5,320,873.84 megawatt-hours/year, proudly producing 5,276,870.41 of those from natural gas (12).    (What happened to the 40% from “renewables”?).  During the same timeframe, San Diego Gas and Electric generated 3,113,925 megawatt hours in power generation facilities owned by the supplier and procured 22,546,881 megawatt hours through wholesale channels.  So SDG&E moved a lot of electrons.  The relevant number for my next calculation is that 3 million plus number.  That’s the juice they generated from the plants that spewed 1,566,434 metric tons of CO2 upward in 2011.  In the decade since, you’ve gotta figure more, but those numbers aren’t available.   So now for the grand equation.  To generate 3,113,925 megawatt hours of electricity, SDG&E spewed 1,566,434 metric tons of CO2.  That comes to half a ton of CO2 for each megawatt-hour (0.5030).   Now take that down to Ken’s Tesla level.   Recall that fully charging a Tesla S consumes 115.2 – 576 kilowatt-hours.  With 1/10th of a half a metric ton of CO2 – 110.25 pounds – generated with each kilowatt hour, that charge is responsible for anywhere from 12,700.8 to 63,504 pounds of CO2.  Taking it back to units in which CO2 emissions are usually measured, that’s 5.8 to 28.9 metric tons of CO2 per charge.  Doesn’t that seem like a lot of CO2 for one car?  And the owner is surely going to be charging it up several times a year. With Tesla’s 303 miles per charge, going 10,000 miles a year will require at least 33 charges.  I’ll do the math for you: that’s 191 to 954 metric tons of CO2 per year.  What about my little gas guzzler?  While I don’t have stats for my dear Patriot, the EPA has kindly calculated that a car getting 22 MPG driving 11,500 miles/year emits 4.5 metric tons of CO2 (13).  So for my part, I’m going to work to save the earth by bellying up to the pump every week.  Each gallon of gas I burn will generate about 8,887 grams of CO2. With a million grams in a metric ton, I’ll have to burn a lot of gas before I ever come close to any Tesla.  Elon Musk should put fake tailpipes on his cars and make them belch smoke just to keep things honest.


  1. TESLA.
  2. energyeage.  Cost of Electricity in San Diego California.
  3. SDGE.  Electric vehicle pricing plans.
  4. CalTrans.  Electric vehicle charging stations.
  5. TESLA.  Charging your Tesla.
  6. LaReau J.  Study compares electric vehicle charge costs vs. gas — and results were surprising.  Det Free Press 10/21/21.
  7. IRS.  IRC 30D New Qualified Plug-In Electric Drive Motor Vehicle Credit.
  8. California Clean Vehicle Rebate Project.
  9.  Governor Gretchen Whittmer.  1/26/22.  c–whitmers-plan-to-lower-the-cost-of-electric-vehicles
  10. SDGE.  Greenhouse gas emission reporting.
  11. Ike B. Behold…WordPress 4/2/22.
  12. San Diego Gas and Electric.  Electricity rates, plans, and statistics.,Electric%27s%20energy%20loss%20due%20to%20business%20operations.%20-3.41%25
  13. EPA.  Environmental Protection Agency.  Greenhouse Gas Emissions from a Typical Passenger Vehicle.,A%20typical%20passenger%20vehicle%20emits%20about%204.6%20metric%20tons%20of,8%2C887%20grams%20of%20CO2.

Published by rike52

I retired from the Rheumatology division of Michigan Medicine end of June '19 after 36 years there. Upon hitting Ann Arbor for the second time (I went to school here) it took me almost 8 months to meet Kathy, 17 months to buy her a house (on Harbal, where we still live), and 37 months to marry her. Kids never came, but we've been blessed with a crowd of colleagues, friends, neighbors and family that continues to grow. Lots of them are going to show up in this log eventually. Stay tuned.

6 thoughts on “smoke and mirrors

  1. Bob, You really do get into stuff. We are getting old. Time to chill. What do we care. Rajiv

    Sent from my iPhone



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