>> Zhengyou Zhang: Welcome everybody coming to our What’s Hot lecture. We’re so delighted
to have Dr. Eric Sortomme come here to talk to us about the electric vehicles which are very hot
these days. And Eric has Ph.D. from the University of Washington. He got the Chairman’s
Award when he was at the University of Washington. Now he works at Alstom and he is also the
chair of electrical vehicles working group at IEEE. So he’s an expert I always think for electrical
vehicles. Please welcome Dr. Eric Sortomme.
[applause]
>> Eric Sortomme: Thank you. And it’s Sortomme by the way; it’s a bad name. No one can
pronounce it right. So, yeah. My name is Dr. Eric Sortomme and I’m going to be talking about
the ABC’s of EVs because it kind of rhymes and it’s a catchy title. What I’m going to be talking
about today, just a brief little introduction on electric vehicles in general; talk a little bit about the
two best-selling electric vehicles as well as plug-in sales; and then I’m going to go into a long
story about taking a road trip in a Tesla and use that as a vehicle to introduce the various issues
that there are with electric vehicles in ownership, charging and some of the grid stuff. So first
EVs. Look at them as they all drive in. Ah, they’re awesome. Why do we want electric cars in
the first place? There are three big camps, reasons why people would want an electric vehicle.
The first is the energy independence and security. Electricity is produced almost entirely with
domestic energy resources. Some from Canada; we import some lovely hydro from there. But
for the most part it’s all locally produced. And also, it’s not dependent on any one particular fuel.
So if there’s a price spike in coal for some reason, it’s not going to terribly affect the price of
hydroelectric or natural gas. Maybe natural gas a little bit, but with a diverse mix of fuels you’re
not beholden on any one particular region or any one particular industry to set the prices like
you are with petroleum. The other one which is sometimes debated is reduced environmental
impacts. At least locally where the electric vehicle is used there is significant reduction in
emissions because the electricity doesn’t make any exhaust at the point of consumption.
Depending on how the electricity is produced, it could be cleaner or dirty. However, the
efficiency of large plants is still much better than smaller distributed engines. So yes, I posit that
there is a better positive environmental impact of driving an electric vehicle even if you are 100
percent coal which no grid in the nation is 100 percent coal anyways; it’s a moot point. And
then, the third reason is the improved driving experience which in my opinion is kind of almost
the most important. There is instant torque available in an electric vehicle from a full stop which
makes it extremely responsive and gives some amazing acceleration. There’s also no engine
noise which gives a much quieter drive. There’s no engine vibration which gives you a smoother
drive. Those are all premium features that people will pay a lot of money for. And with an
electric vehicle that’s just the base; it’s standard. So what types of plug-in cars then are there?
There are city-type electric vehicles such as the Nissan Leaf, the MiEV, the Honda Fit EV, Ford
Focus Electric and a whole bunch of others from a host of auto makers. There are electric
vehicles that can go farther than 80 miles and they only happen to be made by Tesla. 200 plus
Mile EVs I like to call them; there’s not really an official term. And then, there’s plug-in hybrids
which get the sort of high range and the electric vehicle part. So they can go short distance on
electric vehicle mode and then they can extend with gasoline backup generator. They’re sort of
like the bridge in between these two. And technically these are not official categories; it’s
important to differentiate these two as you will see. How do sales look for plug-in electric
vehicles since 2009? And I say 2009 because it was a very important year. Our fine president
made a pronouncement that by the end of 2015, this year in thus 8 months, there would be one
million electric vehicles on the road or one million plug-ins. And we’re sitting right now at
approximately 312,000 so we’re not going to get that goal. Sorry. It’s not going to happen. But,
we’ll get probably about 400,000-ish which is 40 percent. It’s still very good when you consider
that every year more plug-in sales than the year previous. Now the electric vehicle portion –
Dang it. The font has changed on this computer – is 47 percent our pure electric vehicles, and
of that the majority is just of two: the Tesla Model S and the Nissan Leaf. And interestingly over
80 percent of all plug-in sales are just 4 different models: Plug-in Prius, Chevy Volt, Nissan Leaf
and the Tesla. If you were to do this pie chart in terms of money spent, you would find the Tesla
would be closer to around 40 percent because it costs like three times as much as the others.
You could argue that there’s a big market in terms of money to be spent on electric vehicles that
can travel far or you could also argue that there’s a big market for electric vehicles that are just
for high-performance cars in general irrespective of whether they’re electric. So let’s talk about
the two best-selling electric vehicles because it’s sort of an interesting breakdown of the stats.
The Nissan Leaf 24 kWh battery has passive thermal management which means they don’t
have any fans – I think they have fans. They don’t have any sort of liquid cooling. The battery
just radiates heat out into the world and just hope the ambient temperature is cold enough to
have that make a difference. If you’re in Arizona or New Mexico, you could have problems. It
gets 84 miles EPA range which if you’re driving in 70-degree weather on a nice, flat stretch of
road that’s very attainable. If it’s hotter, you do worse. If it’s colder, you do much worse because
heating is more a tax on the battery than air conditioning. It has 3.3 or 6.6 kW AC charging
depending on the option you get. So that just plugs in sort of any wall socket. It can get an
optional quick charger for 50 kW DC charging, and we’ll talk more about that. It seats 5. There is
something else, but once again as I said the font is on a different computer. Must not have been
important. Oh, it was how much it cost. It cost like 32,000 bucks. The other second best-selling
is the Tesla Model S which is 60 kWh or 85 kWh. And if you’re a Tesla fan, you know that this is
dated by like a week because they just discontinued their 60 and replaced it with a 70 kWh allwheel drive. But I didn’t take my road trip in a 70; I took my road trip in a 60 so I’m leaving it up
there because it makes more sense of what we were using. It can go 208 to 265 miles
depending on whether you got the smaller or bigger battery. It can charge from 10 to 20 kW AC
depending on your option. So, much faster. It has an optional 135 kW DC charger which can
really recharge you. It seats 5 plus 2 if you get the option. You can have 2 rear-facing child
seats so it’s bigger. It’s faster. It goes further. But it starts at 78,000 dollars which is also raised
by 5 grand now because they discontinued the cheaper one. It’s still a good deal. Well if you’ve
got that kind of money, it’s a great deal. So now I’m going to talk about how life works with one
of these electric cars in the context of my wonderful awesome road trip to a thing called TMC
Connect. It was once called Teslive. There was some legal spats. So the Tesla Motors Club. It
is a web forum where a bunch of nerdy people that like electric cars, specifically Teslas way too
much, spend too many hours per day chatting about things on the web. One day they decided
that they were going to have an official conference and so, we started going down because,
hey, Elon Musk was going to talk. Who wouldn’t want to see him? Also they were having some
cool panels and they wanted to invite technical people and so, they invited me to give a
presentation. It’s not officially affiliated with Tesla Motors. It’s just a bunch of fan boys going
down to talk electric cars. So that is our context. I am not a person that can afford a seventy
thousand-dollar car and thus it’s very difficult for me to justify bugetarily taking trips down to
California for a web gathering to talk about expensive cars I probably won’t be able to afford any
time in the next decade. So I posted a thing on the forum saying, “Hey, anybody want to
carpool? I will pay for all the electricity for the drive down.” And that’s a funny joke that you will
understand a little bit later in the presentation. And some dude by the name of Paul from
Vancouver BC was like, “Yeah, I’m driving through there. I’ll give you a ride.” And thus, our trip.
We had Paul’s beautiful dolphin gray, 60 kWh Model S to drive us down there. Our route – Well,
the total route of the car was Vancouver, British Columbia, all the way down to TMC Connect in
Monterey, California. And we did Bothell, my house, to Sacramento, California in a single day,
760 miles. And we left at 6:00 AM. We stopped at every Tesla Supercharger, the little T symbols
on the map on the way down there. And we’ll talk a bit more about those. And we calculated our
charge for each leg using a tool called EV Trip Planner. And this is a really cool thing that
somebody just made out of the goodness of their heart. They said, “It’ll help electric vehicles
travel further if you know how much energy you need to get in between any two points.” So it
helps kind of solve the range anxiety. “Let’s route you through chargers. Here’s how much
charge you would need.” And you input your EV type, your average speed that you’re going to
be driving – Be honest because it uses more energy. No law enforcement are looking – what
you want your internal temperature to be, what the weather forecast is supposed to be along
your route, different elements, and it looks at your route and finds the elevation changes and it
calculates how much energy you will need for each leg. We verified. We always gave ourselves
an extra 10 percent buffer, and we found that we were always within the 10 percent. It was a
very accurate tool accounting for like mass, weather, temperature and everything. It was a really
good thing that somebody put a lot of physics into just to give it away for free so we can make
our road trips easier. Supercharging: a free service for all Tesla owners. When I offered to pay
for all the electricity --. He joked. He’s like, “I want you to write a check to Tesla for all the stuff.”
I was like, “No, I’ll pay you for the electricity you had to buy.” There’s a picture of me standing in
front of a Supercharger. The charger itself is hidden behind the fence there, and these are the
bays. They are spaced every 120 to 170 miles along the freeway, so if you’ve got a car that can
do 200 miles you can hit every single one of them. They have 2 to 5 chargers at each site, but
there are twice as many bays. Each charger is 135 kWh and the first car that plugs in to a
charger gets the maximum the car can handle. And then the next car that plugs in gets
whatever is left. And as one car ramps down, the other car ramps up. And so, if two cars
plugged into the same charger with the same battery state of charge, they would hit full at the
exact same time but the first guy would hit 80 percent probably 15 to 20 minutes before the
second guy did. So if you want to charge fast, you see everyone spaces because the chargers
are numbered, 1A, 1B, so on. So we all spaced out so we could charge quickest as possible
and then go. How long? I’m getting to that. I mentioned about ramping up and ramping down.
There’s a little bit Lithium Ion battery charging physics here. As you charge a cell it starts out
with a constant current over time until, as the voltage rise, it hits a certain voltage of the battery.
And then, the current drops off exponentially as it charges faster and faster. So with the first
person that plugs in at the Supercharger, they get this. And the next guy gets the dregs. And as
he starts to ramp down, the other guy ramps up exponentially and they finish at the same time.
But you don’t want to be the guy that – After 80 percent you’re pretty much good to hit the next
Supercharger. So the guy that’s plugged in after has got to wait an extra 15 minutes. But, you
know, it’s free; you can’t complain too much. Technical aspects of supercharging: DC to DC. It
bypasses the car’s onboard AC charger and the Supercharger itself talks directly to the car’s
battery. And it bypasses even the car’s onboard battery management system. The
Supercharger decides how to manage all the cells and everything in there. It is 330 volts and up
to 375 amps. You see the car actually tells you. So we were charging. We were getting 332
volts, 301 amps because we had a 60. If we would’ve had an 85, we would’ve been getting
around 385 amps. But the 60 kWh battery has fewer cells so it can’t handle the same maximum
charge rate as an 85 kWh battery. It’s got a really big, heavy cord because, you know, 300-volt,
400-amp cable with a lot of insulation. It’s also really short and stubby, and there’s some
interesting conjecture about why. And I posited to the people that it was so you couldn’t loop it
up and make a gigantic inductor while you were charging your car. Which now, there are some
people that say, “Maybe we could coil it and see if we could like suspend paper clips in
between?” Who knows? I gave them bad ideas. Yeah, and it’ll charge faster with an 85 than
with a 60. Experience of a Supercharger: so how does it work? How much time? About 15 to 40
minutes depending on how much charge you need which is back to the EV Trip Planner.
Whenever we stopped we knew exactly how much we needed to charge the car up to, so some
of our stops were only 15 minutes. And we really could have even skipped that Supercharger all
together, but we wanted to get the experience of charging at all of them. Some of them were 40
minutes because we needed a lot. The biggest one was when we were going over Grants Pass
in Oregon all the way to Mount Shasta because you go up really high and over. So 15 to 40 for
every 1 to 2 hours of driving depending on. On average about half an hour of stopping for every
2 hours of driving which was sort of nice, relaxing. It’s not terribly slow but at the same time it’s
not super fast either as far as your trip. All of the Supercharger locations have restaurants and
places with bathrooms, mini marts. And some of them had some really interesting places with
local foods. We found a brewery next to one of them that had its own house-made craft root
beer and that made me really excited because in my spare time I also run a blog where I write
about craft root beer. I was taking a picture and drinking their root beer and putting it on my
blog. And they’re like, “Yeah, Tesla-root beer: it works together.” And then you meet lots of other
Tesla owners and you can sit and chat while your cars charge. Somebody’s asking a question.
Do we want to save questions until the end?
>>: 80 miles an hour. At 2 hours you’re 160 miles. Was the car at 200 or 260 range?
>> Eric Sortomme: So ours had 200 range. We were going 70-80 miles an hour which we did. I
mean, we didn’t. So our functional range was about 180 miles. After 160 we would want to stop.
For the bigger cars they could hop in between every other Supercharger. And so you could then
kind of do some optimization to see, well, if I charge at a certain rate, I can put that rate as far
as miles per hour that I gain into my battery. And then, I can look at how more frequently I have
to stop as I drive faster to try and see is it worth it to drive faster to the next Supercharger or
drive slower so I can bypass a Supercharger. And for the most part: drive fast and Supercharge
because Supercharging is faster than you can legally drive. So you’ll like charge it 200 miles per
hour adding mileage to your car. But, you know, we’re engineer nerds. So as soon as we were
like, “Oh, two different rates. Optimize it.” And meeting other Tesla owners to share our stories
can be fun and it can also really annoying because we got stopped at one where the guy just
wouldn’t stop talking. And we’re like, “Okay, our car is charged. Can we go now? Oh, yeah,
great story. Anyhow, we’re off.” So that can be good and bad. I found it overall to be fun. But
Tesla is not the only DC Supercharger network. There’s a CHAdeMO network and there’s me
pretending like it’s a cannon because it’s a huge cable. It has like a huge connector and it had
like a trigger on it. You do weird stuff on road trips. But anyhow, CHAdeMo: it’s supported by the
Nissan Leaf and the Mitsubishi MiEV. No other car manufacturers currently support that
standard. Okay, the EV still does. It didn’t at the time because it wasn’t out. It can do up to 60
kW charging. This is from the West Coast Green Highway; it goes through Washington and
Oregon. And they stuck these like every 50 miles along the freeway. It just happened that one of
the Superchargers across the parking lot was this and they also have another J1772 charger in
there. And there’s also the J1772 Combo Plug which we, on the Tesla Forum, affectionately call
the Frankenplug because it looks like some sort of Frankenstein monster of the original AC.
They just tacked on some big stuff and it’s large and bulky instead of sleek and smooth like
Tesla’s design. You know? Tesla is superior. It can do up to 100 kW charging, so it’s better than
CHAdeMO in that respect. And it’s supported by the Chevy Spark and the BMW I3. So we’ve
got three rival charging networks, charging standards and various cars that do that. However
with every car other than the Tesla, you’d have about 30 minutes of charging time for every 60
minutes of driving which starts getting really annoying really fast if you wanted to take any long
term trips. Technically it is possible; you could drive from Seattle to Southern Oregon in a
Nissan Leaf quick charging the whole way. But you’re at 50 percent charging to drive time so it’s
not a very good ration; whereas, Tesla’s more like 20 to 25 percent charging to driving ratio
starts to get more manageable. But other than those Leaf – Which we didn’t really see any
Leaf’s once we got past Portland because they weren’t out there on the freeway. But we did run
into one other long range EV, a fellow from this area by the name of Tom Saxton who is also
going to the same conference. But he was in a Roadster and they don’t have Supercharging, so
he was going hard core. He had to charge at the J1772 AC which at most is up to 80 amps so
20 kW charging. And it would take three hours of charging for every hour and a half to two hours
of driving. Because, he’s got a cool car. He wants to show off his Roadster at the gathering
along the web. We passed him in Grants Pass, Oregon. I was going to throw a candy at him
and try and get it through his window but I couldn’t find the candy in time. Kind of sad. Let’s talk
about Level 1 AC charging. So I’ve mentioned Level 2 with 240-volt up to 80 amps and the DC.
So after 17 hours of driving and Supercharging and having way too much fun we ended at
Sacramento where my grandmother happened to live at 11:00 PM. She was going to let us stay
the night because, once again, I’m budget-minded and I didn’t want to go for a hotel. Although,
the other guy would’ve been fine. But I was like, “Hey, we could meet my grandma.” And you
have to be polite when you’re traveling. You don’t stay in a hotel when you grandma lives in the
same city, right? It’s disrespectful. Anyhow, we showed up there and we had only 17 miles of
ideal range because I had been driving that part and I had been driving a bit spirited because
it’s a fun car to drive. Big highways late at night. There was a Supercharger in Roseville,
California about 10-ish miles away so that was cutting it a little close. So we plugged in to just
the regular old outlet like you see on the wall over there in my granny’s garage and start
plugging in overnight. She’s got a really old house so the wire is not so good so the voltage drop
was pretty heavy. The car actually detected that the voltage drop was severe and dialed down
its charging current to peasly 9 amps which would’ve taken us over 2 days to fully recharge had
we done that. We charged for 12 hours and got 30 miles of range. So, yeah, to get our 180
back? So 6 times 12 – It would’ve been a long time, a couple days. But that’s okay because it
gave us just enough buffer to make it to a Supercharge and it would’ve been fine. So we’ve got
three different types of charging you can do with an EV. You’ve got just your wall sockets.
You’ve got your nice connectors and your high powered DC. Of course we wanted to go meet
up with some other members in the Sacramento area, so we were going to have a barbeque at
some other rich person’s house that owned a ranch in – Oh, where was it? It was some place
near there. They owned ranch and they called it affectionately Picnic Creek. And she’s like,
“Model S’s can charge at the Supercharger but anybody else that’s got an EV,” like Tom Saxton
who’d be coming in, barely make it in time; he needs to charge. “Anyone else that’s got a
Roadster and anyone that’s got a Leaf or anyone that’s got BMW electric or the Fiat, they can
all charge at my place.” And there was a lot of people that started responding on the forum that
said, “We want to charge.” And being a power engineer here, I said, “Well, wait a minute. If
we’re going to all charge, what’s going to happen to the distribution transformer if everybody
starts plugging in an awful lot of load?” And that got her concerned as well. And she’s like,
“Well, I only have two chargers: an 80 and a 40-amp that’ll be running simultaneously.” I said,
“Well, that should be okay.” And then, just to make sure we called PG and E and said, “Hey,
here’s what we plan to do. Will our transformer handle it or are we going to blow up?” And the
engineer said it would be okay so we said it would be his fault if we blew up the transformer. We
could’ve probably put – She had a 50 Kva transformer; we could’ve thrown another two
chargers at it. But that would’ve been max. There are a lot of people as you see from the drone
photo that someone took of all of our – Even if a quarter of those cars or even if ten percent of
those cars had want to try and charge simultaneously, it could’ve all blown up. And it begs the
question: if someone, not a power engineer, happened to be – Like if there wasn’t somebody
that cared at the gathering and everyone was like, “We’ll just charge,” what could’ve happened
to the grid?
>>: Are they two-phase or single-phase sourced?
>> Eric Sortomme: I don’t know. I think she might’ve been single-phase. It could be either. It
was sort of half rural-residential out there. Yeah, it was big enough. The next day we decided
that we were going to go to Monterey for the conference. We Supercharged our way there. And
then, there was another group of people saying, “We’re going to drive along the Pacific Coast
Highway for 100 miles and it’ll be really scenic and it’ll be really fun.” It was 131 miles. I don’t
know if anyone has ever gone on the Pacific Coast Highway but it goes up and down and up
and down and up and down. And we kind of did our EV Trip Planner but sometimes you had to
pass those slow RVs. Model S corners really well because it’s got all its battery weight on the
bottom. Those curvy roads we wanted to take at high speed and go up. Suddenly we found
ourselves with 18 miles of actual miles to go to our next Supercharger and our car said we only
had 9 miles left. And at this point we were going up a hill because, you know, in between the
coast and the interior there’s sort of gentle hills in California if you know the geography. So we
were going up that and we realized that, “Oh my gosh. We’ve got a problem.” So we had to start
doing something called hyper-miling. Your air resistance from drag goes up with the cube of
your speed. So by slowing down, you can actually reduce a lot of the energy that you need.
Going uphill: well, there’s nothing that could be helped. Though we did know that we had
another hill on the other side, so the car has regenerative breaking so we could gain some back.
And another thing you can do is you can draft off of big semi-trucks because when they go over
they make this huge curly air pocket behind them. And if you can stick your little Model S right
behind there, suddenly you have almost no wind resistance and you can just drive along nice
and slow like the semi until you start going downhill. And we made it with 6 miles to spare. And
the interesting thing about this is we had had breakfast at an IHOP or something while we were
Supercharging and then, we went back. And he was like, “Let’s give it an extra 10 miles just to
make sure.” And I was like, “Oh, I’m sure we’ll be fine.” And the guy was like, “No, I’m going to
give it this extra.” So we sat in the car for an extra 10 minutes for it to get that, and it’s a good
thing we did. If it had been up to me, we would’ve probably died just right before we pulled in.
So even supposed EV experts, there’s a bit of a learning curve. You may think you can do it all;
you can’t actually do it all. Well, you can if you’re careful. And then, we ran into another problem
because we were south of conference that day. We showed up at the Supercharger and this is
what we saw. There were two open slots and our little caravan had three cars driving. So one
person had to wait while everybody plugged in. And then, because we were having a
conference to the north so a bunch of people from LA kept driving up that day and more cars
were showing up. And we were all queued up there. There happened to be another 80-amp
charger offscreen. But it brought an interesting issue of, well, what are you going to do as EVs
start becoming more prevalent? Because, you know, half of these people were going to the
same conference so it was all friendly. We were all good and we’re all Tesla owners. But what
happens when they have multiple makes and models of cars all trying to queue up? Who gets
priority? It could be a problem in the future. It’s something to think about as you do
infrastructure. Maybe there needs to be some sort of – In addition to free Superchargers there’s
like gas station-type ones where you have to pay to get it because some people might look at
the long wait and just say, “Yeah, I’ll pay 10 bucks to charge my car right now so I don’t have to
wait with that.” Either way, they’re going to have to be a lot of them. We finally got to the
conference. I gave my presentation, and my goal was to educate lots of EV owners about the
engineering community has been doing with the research in electric vehicles and how it relates
to the grid. Most of the Tesla owners are not electrical engineers and those that are, aren’t
power systems engineers so they kind of have an idea but they don’t know. First a little
overview of the power grid for anyone that doesn’t know. We’ve got generation which is
renewable because our electric cars are clean. Nice wind power. And we’ve got our
transmission grid, all the big towers that everyone sees. And then we’ve got our substation to
our primary to our secondary distribution to give our full distribution system. And I focus on this
because we get some wonderful electric vehicle problems on our distribution system that the
transmission system doesn’t really have. For our generation I taught them how is our generation
broken up? There is a daily load curve and it’s served by three types of plants that are called
base load, intermediate load and peak load. So our base load is big plants that are very
expensive to build that are very cheap to run but they don’t like to change their output very
much. They’ve got a lot of inertia so they can operate at a fixed rate very cheaply. It’s coal and
nuclear for the most part and hydroelectric up here because, go dams in Washington. But
everywhere else, hydro is not so much used for base load but they don’t have big rivers like we
do. Intermediate load is stuff more like your smaller plants so they’re cheaper in the sense of
capital cost. They have less inertia so they’re more able to change their output as the load goes
up and down. They’re more expensive to run, so these are sort of your natural gas, combined
cycle plants. In some areas they’re actually smaller coal plants. In the Northwest it’s still hydro
because, go hydro. And then for your last little bit you’ve got these very cheap plants. Because
they don’t very often, they’re cheap to build. They can turn on; they’ve very responsive. But,
they’re really expensive to run. That’s things like combustion turbines or in some cases
reciprocating engines. This is the really expensive, dirty power. This is the cheap power,
intermediate power and in the Northwest it’s all hydro for the most part. Though, Puget Sound
Energy has got some natural gas as well as some of the other utilities. We’re still 70 percent
hydro. So what sort of issues do electric vehicles cause when they start charging for the bulk
generation? As you saw with previous Supercharger things: when you get a line of cars at 135
kW a piece you’re starting to run 0.5 megawatt to 1 megawatt of power. It starts becoming a
very serious load. As you have that distributed all over the state you’re going to need a lot more
energy, not just for the Superchargers but just cars in general. As you transfer a type of energy
usage from one fuel source to the electricity, you’re just going to have more energy. You’re
going to burn more fuel in the plants that you’ve got. Sadly, if you’re hydro, you only have a
finite amount of water that comes down your river. You’re going to have to spill a lot more of it
and that could be an issue. Also, you can add a lot more load levels, higher loads, because this
stuff could happen coincidence with demand. You might need to build more peaking plants, or
you’re just going to have to run your other peaking plants for longer so it could be less efficient
to charge your electric cars. So, there are some issues with that; though, it’s not the main one.
And then, some people say, “Well you know, electric cars, they can pair well with renewables
and we’ll just charge them when renewables are going and then it will solve all the problems.”
Well, sort of the problem with that is just when are your renewables generating? In some places
you get lots of rooftop PV that are changing your load curve. Here is what’s actually happening
in Hawaii on lots of distribution feeders where they’ve backfeeding in the middle of the day
because they’ve got so much solar on their rooftop PV. And they expect that California’s total
load to start looking like the Hawaiian load in the future. So if you wanted to sort of charge in a
way that’s friendly to bulk generation for your electric cars you say, “Well, I guess charge them
in the middle of the day,” because if you want to pair with renewables that’s what’s happening.
But what if you live up here in the Northwest or just any place where you’ve got a lot of wind?
Here’s BPA load curve for one day in January and here’s the actual wind generation. And you
notice that the difference between load and wind is really tiny at night where it’s very big in the
day. So in this case you’d want to charge your electric car at night to be friendly to the grid
which is opposite of some other places if they’ve got solar. And that doesn’t consider our
distribution grid. So what happens when we charge electric vehicles on the distribution grid?
You can have line over-voltages. We can have voltage sags because we keep adding more
load. On our secondary distribution we can have transformer overloads. We can have the
secondary triplex lines also overload and catch on fire because they’ve got rubber insulation on
them. Members of our club forum had posted about different events where they had met up, a
bunch of EV owners, and there was wonderful stories about secondary distribution lines
catching on fire and burning down and suddenly the entire block going dark because they blew
up the transformer. And, oops. Or, they went to a mobile home park and they blew up the
mobile home park’s – the RV park’s transformer too. And the beauty was that these failures
didn’t – some of them happened in the middle of the day. Some of them happened while they
were trying to charge overnight, so there wasn’t really any sort of hard fast rule of, “If you want
to be friendly to the grid, when should you charge your car?” And so the solution that’s sort of
being – Yes? Question.
>>: Why wouldn’t the house breaker break first or main to protect it?
>> Eric Sortomme: Because it wasn’t quite enough overload current to be seen as like a short
circuit, so it was just barely enough to overheat the insulation and light on fire in that case. And
with the d – That was when the secondary line caught on fire. The one with the distribution
transformers blowing up is because it didn’t overload their house but all the houses were heavily
loaded and that was just the final straw.
>>: If everyone in my neighborhood drew 190 amps on a 200-amp panel, the line would start
burning?
>> Eric Sortomme: Yes. Sure, absolutely. Yes, definitely. If you and all of your neighbors max
out your loads of your house but keep your breaker not overloading, the transformer will blow up
unless your utility really liked to buy extra large transformers.
>>: That’s because the utility is not required to follow [indiscernible].
>> Eric Sortomme: It’s also because the probability of that happening is extremely small, where
you don’t usually have all of your loads synced up.
>>: And they size their wire [indiscernible] which they’re small.
>> Eric Sortomme: Yes because you want to be cheaper. So, how could we solve this
problem? So the current research and the stuff that I’ve been looking at is one solution is a
charge valet that would be offered by what I call an electric vehicle aggregator, somebody that
collects the information from a lot of electric vehicles and can tell them when the best time to
charge is. They would have global knowledge about the system conditions. They would be able
to ensure that the car got charged when they needed it. And they could match the owner – They
say, “How do you want to charge your car? Do you want to charge it with the lowest CO2 on the
grid or do you want to charge it at the cheapest price? Or do you want to charge it with the
friendliest to the grid because you’re a power system nerd and you just want the grid to be
happy?” And they can match your charging objectives for you, and they can give you periodic
reports showing you your savings as far as CO2 saved or money saved or transformers saved
from an untimely death. They could also couple this stuff with more advanced Vehicle-to-Grid
solutions. Vehicle-to-Grid? What is that? That is the provision of energy and-or ancillary
services from an electric vehicle to the grid. So your car would be sitting there charging into the
grid. You would know its location through GPS. Wireless provider would be able to talk to your
car over the Internet. Driver’s usage profile and preferences would be known by this aggregator.
He would sell the car’s ability to change its output to the grid operator for money and some of
that money would come back to you. Why does that work? First we need to understand
something about energy markets. Here is a daily load curve. Every hour they do something
called Economic Dispatch of their generators and set their generators to generate in nice fixed
blocks of power and there’s pricing for that. But you’ll notice that doesn’t quite fit the curve and
so they have what’s called Frequency Regulation which takes out that higher frequency
component and smoothes it out as it out as it travels within the Economic Dispatch. And then,
you have the case where what happens if suddenly one of your generators trips offline for some
reason? You need emergency reserve or responsive reserve in some markets. Be able to turn
on a bunch of extra generation to meet that or drop a bunch of load. And these in places not in
the Pacific Northwest where they have lots of cheap hydro but other places, they have a market
for all of these solutions. And participating in these markets can be extremely profitable
especially if your dispatched cost is negligible like it would be for an electric vehicle. So some
aggregator would go into the market and bid all sorts of cool capacities using sweet algorithms
like the ones that I came up with. And then, how would it look for you, dear owner of your Tesla
Model S? You would have your car. This is the display of the car while charging and it says
what your charge current is, your battery state of charge. And your car can be set up to
automatically – The telemetry in this case I said was Twitter because it can be done, but you
can have a more advanced telemetry. It says, “Bob’s Tesla is currently charging at 40 amps.
Battery level 75 percent.” And then, the EV Aggregator says, “Oh, the system tells us we need
to charge more.” So suddenly it sends a command, your charge rate adjusts and then, telemetry
comes back, “Oh, he changed his charging rate.” And then, suddenly they need you to do less
so it goes down to 30 amps. The next instance it would go down to 23 amps, etc. And so they
could make your car charge all jagged instead of smooth which doesn’t affect your car’s battery
or anything but gives the grid nice smoothing, gives the aggregator nice money, gives you nice
money and you can still be doing that within your Charge Valet preferences. And that starts
getting a beautiful electric vehicle ecosystem, and that’s the cool research that I’ve been doing.
And everyone in the Tesla thing was like, “That’s amazing. Where can we sign up for that?”
And, “I don’t know.” It looks good on paper. For some reason no one’s yet made a commercial
project. Someone in this area had started making a commercial product out of that and then,
they sold it to Grid Point. Who knows what they did with it? But anyhow, when it was all done we
decided to go back. At 2:00 PM we left Monterey and we drove all night to get back so I could
go to work the next day which actually was – Before all night driving could be sort of a pain. If
you have to stop at a Supercharger for 20 to 30 minutes suddenly the whole, “No, it’s okay. I
can do it,” and falling asleep at the wheel is less of an issue because, “Oh, I’ve got to pull over
the car.” And then, the passenger is like, “Well, let me take over.” So it was very easy for us to
switch drivers, get naps, get more caffeine; there was no impetus to keep driving through all
night and go past your limit. It really couldn’t happen as easily in EV, so suddenly there was a
big plus from driving an EV all night. We got home at 10:00 AM the next morning. So, it was a
long trip. And then, we plugged into my garage which has better wiring than my grandmother’s
so we could get 12 amps, 33 percent more, for 3 hours while we took a nap because we were
tired. And that got him enough buffer so he could head off to the next Supercharger up in
Burlington and then head off to Vancouver. And that was our wonderful trip about EVs. And the
conclusion was: EVs could actually work as your only car if they came with 200-mile range and
they’ve got some sort of quick-charging solution. You don’t need another car. You can do it.
“Oh, I need to drive down to California in a day,” at like a moment’s notice: done. I think roadtripping in an EV is actually more relaxing than regular road-tripping. Because of my grandma
that lives in Sacramento, as a child growing up in Eastern Washington, we made that trip all the
time. And my dad was the sort of fellow that stopped for breakfast and stopped for lunch, and
we were going to be in Sacramento for dinner time. And as a kid it gets really boring in a car.
Whereas with the Supercharger, you have to stop and you can run around. You can stretch your
legs. You can see some cool stuff. I had no idea about some of the cool restaurants and things
that there were along that path, even though I’ve driven there before like 10 times back and
forth, because we always skipped it. However, as we learned on our PCH drive there is still a
learning curve even for the experts in the field. We almost got stranded. And also that EV
charging issues for the grid can be solved through intelligent charge management and Vehicleto-Grid solutions. And that’s it. Thank you. Any questions?
>>: Yeah. How would that trip have been if you were going from Billings, Montana to
Minneapolis, Minnesota in January?
>> Eric Sortomme: Well, if the Tesla Supercharger network were there – I don’t think it’s quite
completed along I-90.
>>: Ten degrees below zero and you’re stopping for a half-hour to charge your car. Would that
extend – The heater has to go, right?
>> Eric Sortomme: Yeah, it would probably extend your charging time a bit. And thankfully the
Superchargers just aren’t off in the middle of nowhere so you’d get inside a building and warm
up, which is what we did anyways. So, yeah, cold weather can make it more difficult. Yes?
>>: You mentioned there was a bigger issue to the batteries by [indiscernible].
>> Eric Sortomme: Yes. If you’re discharging, there’d be degradation. But if you’re just charging
it, like…
>>: But you can vary your charge, definitely not having issue with the warranty?
>> Eric Sortomme: Yes, you can.
>>: Do you think they’ll ever allow you to discharge?
>> Eric Sortomme: Nissan, as a result of the earthquake tsunami, added an option on the Leaf
called Vehicle-to-Home because a lot of Japanese customers were stranded without power for
like a week. But they had Leafs full of charge and they thought, “You know, I’ve got enough
kilowatt hours; I could run a rice cooker for a while and eat dinner.” And that was specifically
their use case, run a rice cooker from your Leaf. And so they’ve got it as like a couple thousanddollar option. If they do allow discharging under warranty, it’s going to be an expensive enough
option that it will cover the fact that you’re going to wear out your battery faster most likely.
>>: Yeah, my understanding is that the Leaf has that built into that as a technology but it
requires some sort of modification at the house level to dump into the grid. But the biggest
concern is the degradation and artificial cycling of the battery. Have you done any research?
>> Eric Sortomme: I haven’t done – I’ve use other people’s research as far as pricing for
optimization within markets of battery degradation; I haven’t done that myself. So, yeah, Nissan
has it as an option that you can enable. You would still need to make stuff in your house where
you’d make sure to disconnect from the grid so you’re only powering your house, just as you
would with any sort of backup generation. So you’d have to pay money for the Leaf to do it and
then you’d have to upgrade your house to be able to handle.
>>: Explain the degradation you’re talking about, that when you drive the car it exhausts the
battery.
>> Eric Sortomme: True. Car manufacturers give you a warranty in terms of time and mileage.
And if you are charging and discharging your battery into the grid to make a bunch of money
then you’re wearing out your battery in ways that are faster in time and not at all related to
mileage. So suddenly, “Oh, I only drove my car 20,000 miles and the battery doesn’t retain
charge.” Well, yeah, but you were discharging it 5 times a day to take advantage of local energy
spikes. We’re not going to warranty that if you’re going to do it. That’s sort of the issue with that.
>>: Actually, the Minnesota example in the winter. I’ve read that range can be reduced as much
as 40 percent.
>> Eric Sortomme: It can. Not as much with the Tesla because of the active thermal
management and the battery insulation they have. As well as if you live in a place with
extremely cold weather, you can add additional insulation and thermal management to your car
with a cold weather package. So there is that. But, yeah, if you get super, super cold it will affect
your range. It also affects a gas car, though, not as much because most of the waste from an
internal combustion car is heat. In the cold weather, suddenly that wastefulness comes in
handy. With an EV, not so much.
>>: That 40 percent is actually using your heater, though. If you don’t use your heater…
>> Eric Sortomme: The biggest problem is resistive heating in the cars because in a gas car
you’ve got the heat so you can just turn on a fan and blow it into the cabin instead of having it
radiate. Whereas an electric car, you have to run resistive heating elements which are a huge
power draw. They might pull 5 to 10 kilowatts. And so if you’re driving then that – If you drive for
2 hours, that’s 20 kWh of energy that you’ve lost out of an 85-kWh battery. So there goes…
>>: Two hours at thirty below. You want heat.
>> Eric Sortomme: Well, I’m just saying that’s the problem. If you bundle up in your parka
and…
>>: No way.
>> Eric Sortomme: The one guy – For mass market, no. But, you know, for our crazy
enthusiasts like the guy that drove from Seattle to Monterey stopping for three hours at every
charge point --. Yes?
>>: So in your research what you came up, [indiscernible] is basically you’re just talking to the
car and telling it – so you can level the grid out there.
>> Eric Sortomme: Yes.
>>: As to when it’s really high peak hours, lower the amount of charge so you can even out in
the area.
>> Eric Sortomme: Well, really the research that I did said, “I don’t care about the grid
conditions. I care about the market conditions and pricing.” And the grid operator tells me what it
wants and I told the grid operator what sort of flexibility I have in the car based on all of the user
preferences and where I expect them to go and what their battery states of charge are and how
fast they could potentially charge based on their connection. And I say, “Here’s my flexibility.”
And the grid operator just sends me a dispatch signal from the market things and I --.
>>: [inaudible] use as much as possible because he makes less energy at the peak hours.
>> Eric Sortomme: Well, it depends on how the market dispatches. A lot of times they dispatch
all of their resources equally. Yeah, there are a lots of different things and that starts getting into
sort of the optimization dynamics and market stuff. But, yeah. There are lots of things.
>>: How much is your round-trip efficiency on the Vehicle-to-Grid? So charging the battery then
bumping it back to the grid. What’s the overall efficiency?
>> Eric Sortomme: I think it’s about 80 percent for all batteries. I don’t know, someone that
works with battery stuff might know better. It’s about a 90 percent charging efficiency, so
assuming that your bidirectional inverter works about the same and your internal battery losses
aren’t terribly much. So, around 80 percent round trip.
>>: 80-90.
>> Eric Sortomme: 80-90, yeah. It depends on a lot of different variables. When I did my
modeling I said 80 percent round trip efficiency because I wanted to be inefficient so I was
making a conservative guess on the amount of money you could make by doing this.
>>: Are there any tow trucks out there that’ll bring charge out to you?
>> Eric Sortomme: AAA actually now has in certain areas a CHAdeMO, the Nissan Leaf one
where they’ve got a 10 kWh battery or something connected to the CHAdeMO thing so they can
pull over to a Leaf and give it a quick charge blast. Or they can have a J1772 connection so
they can give you enough to limp home. In certain areas, yeah; AAA has got your back. Yes?
>>: How about battery swapping?
>> Eric Sortomme: Well, Project Better Place was really into battery swapping and they went
bankrupt. So there’s that. Tesla has said the Model S is capable of battery swapping and has
built a battery swapping station at Harris Ranch and has done a few pilot battery swaps.
However, that’s large – We speculate that it is more because they get more California Air
Resource Board Renewable Credits for selling a car that is capable of swapping its battery even
though none of them do. So they built the station, swap a couple people’s batteries so they earn
more credits with every sale even though 99.99 percent of all the Teslas in the State of
California will never swap their battery. It’s possible. Some of the economics get interesting with
it of, you know, like where do they store all these batteries? What if I get a bad battery when I
used to have a good battery? And as a said, Better Place tried it. It failed. Tesla may try it if they
find that people – that they can make money off of this battery swapping solution; I imagine that
they would go for it. But the logistics seem difficult if all the cars are owned by different people. If
you have a fleet of cars, say 200 cars, and you own them all and you own the batteries, battery
swapping is a wonderful solution because whenever they pull up into their bay you swap out the
batteries and you go. So battery swapping can work. Yes?
>>: So I see a lot of fires from the Teslas.
>> Eric Sortomme: No, no, no, no, no, no, no. There were not a lot of fires. There were three
fires. Two people ran over trailer hitches which speared into the battery. And if you take your
laptop battery and you drive a screwdriver through it, it’ll probably catch on fire and explode. So
there was that. And then, there was also some guy in Mexico that was driving 100 miles an
hour, flipped his car, crashed through a brick wall and the car lit on fire. And he walked away
from it rather unscathed for being an idiot and wrecking his car in Mexico. There was that fire.
So one was an idiot and two were big old trailer hitches that got hit and then driven impaled by
the car. Then Tesla added a big bunch of titanium sheeting, armor plating underneath it to make
sure that would never happen again. And then, they released some wonderful videos of them
like driving over three ball trailer hitches and the hitch getting destroyed and driving over a
cinderblock with the new battery armor and the cinderblock getting destroyed. So, yeah, there
were some fires and it generated some bad press so they put some ballistic armor on it.
>>: Something tells me Tequila had something to do with that last one.
>> Eric Sortomme: Yes, the one in Mexico – Yeah. That’s not fair to say it’s about car safety.
Anytime someone rams a car through a brick wall at 80 plus miles per hour, you can expect bad
things to happen to the car. Yes?
>>: Is Tesla planning to continue build out the free Supercharge stations and is it sustainable?
>> Eric Sortomme: Oh yeah, they – Well, so Supercharging – If you buy their most expensive
car, it would come standard. If you bought the cheaper, 60 kWh one, they made you pay 2,000
dollars for the software unlock of the Supercharging hardware, which really meant that you’re
paying 2,000 dollars for the ability to charge. So, I doubt you’ll be using more 2,000 dollars
worth of energy in that. So it’s really – The pricing of Supercharging is built in with the car. It’s
pay upfront instead of pay as you go. And also Tesla justifies Supercharging out of their
marketing budget because it’s instead of running advertisements they have Supercharging
because people can go. And most people don’t actually use Supercharging that often. But,
yeah, it’s an interesting question. As you start getting more and more people, could something
like that be sustainable? And my personal opinion is that just because you’re going to get
saturation of not enough Superchargers for free that you’re going to see people build a
Supercharging station that’s a pay-per-charge like 10, 20 bucks your Tesla. And they’re going to
build them probably close – either completely away from where existing Superchargers to
bridge a gap or they’ll build them close to a heavily used Supercharger. You get there and it’s
already completely full and two other Teslas just pulled in the lot and then you see across the
street, “40 bucks. Charge your car now.” And, you know, if you can afford a 100,000-dollar car,
do you really want to wait a half an hour just to charge? So, you can get on your way. Currently,
Tesla hasn’t licensed it to be pay because they want to say free Supercharging but I think it’s
going to happen. It’s going to happen eventually. They’re not going to give away free charging
forever.
>>: It seems like if one of the Supercharging stations went offline, it’d be a major problem. Has
that happened yet?
>> Eric Sortomme: It has happened. The entire charging station has happened a few times. I
don’t know the specifics. A lot of times because there are multiple chargers at each one there
have been times when entire chargers have gone offline. And they actually have a little number
that you can call if the Supercharger is not working. And sometimes there’s a problem with your
car and they can actually talk to your car remotely. Like, someone needed a firmware upgrade
to use the Supercharger and so they got it hashed out in like 15 minutes and the person was on
their way charging again after that. So their very much trying to diagnose and get all the
problems --. But yeah, right now the entire network is only Tesla. And if the distribution
transformer for the Supercharger blew up then everyone is stranded and out of luck. So I would
like to see in the future pay charging solutions alongside free charging solutions, premium
membership.
>>: How about hybrids like Toyota Prius? [indiscernible]…
>> Eric Sortomme: Yeah, I talked about that at the beginning that they’ve sold a lot of those.
With the plug in Prius if you don’t have a place to plug in, you just go and buy gas which is what
it is with all the plug in hybrids.
>>: So there’s more flexible…
>> Eric Sortomme: I personally say no because I’m one of those purists where I like an EV to
be an all EV and I like a gas car to be an all gas car.
>>: [indiscernible] adventure you talked about in the beginning, the three [indiscernible].
>> Eric Sortomme: So the plug in hybrid is essentially an EV that can’t go as far or in some
cases as fast at like its maximum top speed when it’s all EV mode. It’s like two cars mushed into
one; instead of having a Nissan Leaf and your Asics, you’ve got a Chevy Volt or something. So
you can do both. Some people say it’s the best of both worlds. I like to say it’s the worst of both
worlds. But it gets dogmatic. But, yes, they’re very practical and they have a lot of advantages of
plug ins.
>>: [indiscernible] cost as high as pure EV?
>> Eric Sortomme: Battery. The biggest expense of the electric car is the battery. So if you
make a smaller battery --.
>>: In the future because you still have your gas engine to be repaired like normal gas engines.
>>: Oh, I see.
>> Eric Sortomme: There are pros and cons. It is easier to transition from a regular internal
combustion car to a plug in hybrid car because if you forget to charge it, you can always just fill
it up with gas.
>>: Just to add, another nice thing about PHEVs is that most people drive like 30 miles in a
day. Most of the PHEVs that are usable have like a 30 to 40 mile range on electric. So you
could very well drive around the city as an electric car and never touch the gas. And then, when
you wanted to go on a road trip, like a Tesla road trip or whatever, you could just fire up the gas
engine. It would instantly engage and you’d keep driving.
>>: Yeah, much better.
>> Eric Sortomme: No, no, that’s terrible. We need to all go EV. Because then you don’t get to
Supercharge and you don’t get to drink root beer. You only get to drink root beer at the
Supercharger. Yes?
>>: You talked about all the fun things you did while the car was charging, but doesn’t
somebody have to stay with the car to move it as soon as it charges?
>> Eric Sortomme: No, it was fine. As long as there were extra bays – In the time where we
were overloaded then you can look at your smartphone app – Everyone has the Tesla app for
their smartphone and it can tell you exactly the state of charge and so you would know when it’s
going to be done. And you can even estimate how long it will take based on what you’re at when
you plug it in.
>>: Last one.
>> Eric Sortomme: One more question. Jason, you can ask it?
>>: Second-life batteries: how could those be used for the grid?
>> Eric Sortomme: You set that one up, didn’t you? Yeah, so there’s a lot of talk about after the
EV batteries are technically dead for a car, they would still be able to retain like 60 percent of
their capacity, that then they could be bundled into some stationary energy storage product and
then cycled until they’re completely all dead. And that could be a much cheaper solution. And
potentially if you had some sort of modular architecture for batteries that were chemistry
agnostic and vendor agnostic, you could really integrate things like second life batteries into the
grid. Don’t know who would be doing something like that. No, that was the last question. Sorry.
We have to…
>>: We are over. We have an [indiscernible] coming up so if you would like join us, please
come. Thank you very much.
[applause]