Hello, back to Energy 101, and today we're
going to talk about electric car carbon
emissions.
In my introduction somewhere on my, main
page for this course I made the statement
that electric cars do not save carbon
emissons.
I put that on there to be controversial,
and it certainly did create a lot of
controversy.
It got more comments than almost any other
topic, which was good.
That's what I meant for it to be.
And it is a controversial statement.
But the reason that I put that up there
and the reason I addressed this is, I was
always amazed that the electric car
manufacturers, this happens to be a photo
of a Leaf, got emblems on it that says
zero emissions.
And Ifelt like that might be a little
misleading.
The zero I feel is misleading, now it does
have zero tail pipe emissions because it
doesn't have a tail pipe.
No question, but, let's drill a little
deeper and see if when you buy an electric
car, if you really, when you drive it are
you really, producing zero carbon
emissions then like I said, I'm taking a
particular case, and you can debate the
zero statement.
You can always come up with a scenario in
which the zero is, is true.
But let's look at the one that I feel like
is, is the appropriate one from a public
policy viewpoint.
And when you look at it from an individual
viewpoint, it can be different.
But the question, do all-electric cars
have 0 emissions?
View from the US or, are, do they reduce
emissions is the probably a more nuance
question.
It definitely is a more nuance question.
But I want to take the view from a US
public policy viewpoint, not.
From a personal or regional viewpoint.
So, when I say public policy how much do
current tax incentives that put more
electric cars on the road throughout the
US, all over the US reduce CO2 for the US?
Because it's an, it's a international
problem.
So emmisions that are produced in
California affect New York and Florida
then vice versa.
So as a, we need to look at it from an
energy policy and global warming policy
viewpoint, from a national perspective.
So, not from an individual or regional
perspective.
You can get a different ansewr if you look
at a personal situation, where if you're
off the grid, for instance.
And getting all your electricity from
solar or wind, the answer is you burn damn
close to zero, okay.
No question about that.
Nobody can debate that I don't think, if
your off the grid getting it from
renewable energy.
But, that's not the typical situation I
would contend if I hadn't run the number
that is probably less than 1/10 of 1%.
And 99.9% are going to get it from the
grid.
So let's try to answer that question.
Well, number one we have to look at, where
does the electric car energy come from.
And, when you, you plug it in to recharge
it, and it gets no, no energy from
gasoline, you don't have a gasoline tank,
and we're talking about all electric cars
here, ones that run totally on electricity
like the Leaf.
The Leaf is a I keep using that example
because that's the first really
mass-produced electric car by a major
international car manufacturer, such as
Nissan, as the Leaf is.
But all the energy comes from the electric
grid.
None of it comes from electricity.
The Chevy plug in hybrid as we've talked
about is, is different.
It gets some from gasoline, some from
electric grid.
The Prius that's strictly a hybrid that's
been out for 10 years it gets all of it's
electricity from gasoline.
We'll talk about that.
But the electricity generated for charging
the batteries does create CO2 at the
electrical power plant.
In general when you're looking at the grid
as a whole some of that electricity going
into that grid has been generated by
fossil fuels that emit CO2.
So let's dive a little deeper in this, and
see, and see.
How we can calculate this number.
We've gotta make assumptions along the
way, and you can change the number of, of
different assumptions.
So, it's a great, great question for
discussion and calculation for a
discussion that depends on the assumption.
So I'm going to give you my assumptions
here, hopefully.
But how much if, we want to look at how
many kilowatt-hours are required to drive
the electric car one mile, that's the
first thing we need.
We need to know how much electricity has
to be generated, and put into the grid,
due to the fact that we now just bought an
electric car, or bought 1,000,000 of them,
and put them on the grid.
Well, the, the Leaf, according to US, EPA
it's, it's like fuel mileage that they
quote.
Usually is about 1/3 of a kilowatt hour
per mile, 1/3 of a kilowatt hour per mile
and that inverted means it, it gets about
three miles for every kilowatt hour used.
Three miles for ever kilowatt hour used.
So somewhere, when you generate a kilowatt
hour it will drive you approximately three
miles, and by the way, these kinds of
calculations, you can debate plus or minus
10% on any of these numbers.
You can debate plus or minus 20%, so...
I don't try, I try to stay out of the
fractions and decimal points and those
kind of things, because we're trying to
look at the big picture and reach a big
policy decision question here.
So, but the next thing, so the next thing
we need to know.
Is, how much CO2 is emitted for each of
those kilowatt-hours that is generated and
put into the grid, for that, battery to be
charged, in our, electric car.
Well, if you take the total CO2 emissions,
and the, carbon emissions from power
plants All power plants, and that.
You get that number.
I got that number, from EIA, Energy
Information Agency, the, off the web.
Then divide it by the total US kilowatt
hours delivered.
Then that gives you pounds or grams of, of
CO2 per kilowatt hour produced and put
into the grid.
And by the way, the, I, the number comes
out to about, to 1.2, approximately 1.2,
1.12, 1.3, 1.23, 1.818, is, is in that
ballpark, which by the way is 545 grams
per kilowatt hour.
So, so that means then that the pounds of
CO2 produced per mile driven in your
all-electric car, that gets a third of, of
a, I think it's three miles per
kilowatt-hour, such as the Leaf.
Is 1.2 pounds divided by 3 miles per
kilowatt hour, or .4.
So you've got about, the electric car, the
Leaf type, will get about .4, or produce
about .4 pounds of CO2 at the power plant
to generate the electricity to carry the
car about one mile.
Now, that's the sum total of the ceo2
produced by all the power plants that feed
into the grid that you're charging the
battery off of.
Now, we need to look at the gasoline
driven so we can compare it.
What's the gasoline driven car co2
emissions?
Well, you can look it up again on e-, e-,
Energy Information Agency, which is where
90 or 98% of my data comes from it's a
very dependable source.
And it comes out to about 19.6 pounds of
CO2 per gallon of fuel burned.
19.6 si, a pound per gallon of
fuel[INAUDIBLE].
It's kind of interesting, a gallon of fuel
wry, weighs only about 6 pounds but it
produces 19 1/2 pounds of C02.
And of course the reason for that is, the
gasoline is made up of C Carbon and
hydrogen.
And then you take the oxygen out of the
air and that oxygen reacts with the
hydrogen.
So, now you've added oxygen to the carbon.
And that, that mass is higher than the
original carbon and hydrogen that we use
to begin with.
But, That, now, if you, know the miles per
gallon.
That, that car gets, then we can calculate
the CO2 emitted per mile driven by the
gasoline car.
And so if you, you just take 19.6 pound of
CO2 per gallon and divide it by the miles
per gallon of that particular car.
So in order to get equivalent, you can
play around with it and calculate it
exactly, but essentially, if you take a
pri, prius hybrid that runs totally on
gasoline, it generates some electricty
for, for itself when charges a small
batteries when you come to a stop due to
breaking and uses it back.
When you, start back up, but it gets none
external, no electricity external from the
car at all.
It gets all it's energy to drive on gas,
from gasoline.
And you come out with about .4 pounds per
mile.
Well, I use the 50 because it's about
equivalent to the leaf to the electric
car, and so, So the, and they are similar
sized cars, similar performance.
There's not a heck of a lot of, I don't
think someone a person shopping for a, for
a Leaf, is going to be also considering a
GMC Yukon, or something.
A big SUV.
So you gotta, you gotta compare apples to
apples here, I think to have a rational
number in my mind.
So is US av.
The next question though to ask, is the US
average co2 emitted per kilowatt hour the
proper value to use?
That I came up with the 1.2, remember, I
just took the total CO2 produced by all
the power plants.
And divided by the total kilowatt hours
produced by all power plants.
Well, I claim that that's probably not the
right value, because it's too low, due to
dispatching issues.
In an electric car, it's mostly charged
overnight.
And there are lots, there's lots of excess
power capacity at night, probably.
And some people argue we've got to build
more power plants, to, meet, the cap, the,
charging need for all these electric cars.
But that's not true, since most of them
are going to be charged at night, and we
have low demand at night.
And there's plenty of power plant capacity
to, to meet the increase charging demand
from these new electric cars that we're
putting on.
But, the incremental electricity will not
come from renewables, is one strong
argument that you can make.
Because they're already being utilized
100%, so when you put an incremental load
of one electric car, or a million electric
cars, onto the grid, you're not going to
get anymore electricity renewal just
because you're using all that anyway.
The economics demand it.
The real operation demands it.
You just don't turn off wind turbines.
You take the electricity any time you can
get it.
Same way with Photovoltaic, and power
towers, and all that.
So, it's a dispatching issue.
So, I claim that, you can argue strongly
that you going to have to use the, and do
use the fossil fuel coal and gas plants,
which is the last ones that you turn on
and off, to meet the incremental demand.
In order to meet the increased demand due
to the electric cars that need to be
charged.
That's, certainly, an, an, a, debatable
position, and I think it's a position that
you can defend.
So the conclusion on this, and again I'm
going to look, I'm looking at it from the
U.S policy viewpoint, not for an
individual situation or an off-grid
situation.
But number one, I certainly think that's
it's a little unrealistic to talk about
electric cars, have zero emissions, and i
really don't think that statement in
general is true, and I think it's at least
some misconception.
It's true if you, you, just from the tail
pipe situation.
And if you just view it from a isolated
situation where you got solar equipment
just serving a car electric car charge it
yourself, but that's a pretty dumb
application for solar because it's sitting
there not being used unless you're
charging the car.
But anyway.
I'll let you debate that.
The CO2 mile per mile then depends on the
dispatching issue.
So, if and by the way if you just look at
the CO2 emitted from incramentally
cranking up the, the nonrenewable
non-nuclear.
Power plants you get about 1.7 pounds of
CO2 per kilowatt hour per use.
Not the 1.2 that I used in the example to
get 50 miles per hour.
Well when you use the 1.7 assuming that
the, the electricities going to come from,
because of dispatch reasons.
From the coal and gas power plants.
You come up with about 30 miles per
gallon.
So, I believe that there's no black and
white answer to this.
And you can change your assumptions and
get different answers.
But, I believe that the range of 35 to 50,
in my mind, is a pretty.
Good range to look at and consider that
the CO2 emissions from electric car, like
the Leaf, getting a third of a, of a
kilowatt per mile is will produce.
Now as I said, you can make your own
assumptions in the limitations and look at
different scenarios and come up with
different answers.
And you can look at where we might be 20
years from now, or 40 years from now, that
I think this applies for those being put
on today.
And it helps us to make some decisions
about what we need to do with our power.
Plant fleet that is feeding into the grid.
If we want to do something about CO2 we
need to deal with this issue.
But electric cars are good, by the way,
from the oil savings, so they definitely
save oil.
And we need them if for that reason alone.
And they certainly don't seem to produce
any more significant CO2 emissions.
But I'm not sure how much it'll help us on
the CO2 emissions.
You make up your own mind.
I tried to equip you in this course for
looking at the facts, and then using the
facts to analyze your questions and come
to your own decisions.
So thank you for listening and hopefully
that'll generate some more discussion.
Thank you.