20230611

Electric Versus Gasoline

 After the previous post, I got to wondering: since I said we weren't burning gasoline to make electricity (and so the comparison was not exactly fair), what would the real CO2 comparison actually be?

Let's crunch some numbers!


Basic Figures

For the purposes of this calculation, we'll make the following assumptions:
  • We're going to send our gasoline and electric vehicles 50 miles.
  • The electric will consume 350 watts per mile.
  • The gasoline vehicle will go 15 miles per gallon (3.96 miles per liter).
  • The electric will use coal-powered energy, at 2.32 lbs of CO2 emitted per kWh consumed.
  • The gasoline vehicle will produce 5.09 lbs of CO2 per liter of gasoline consumed.
Why these numbers?  Because of the two vehicles I own, these are not outlandish and actually quite common consumption figures.  We'll play with numbers below.

The First Calculation

Given the above assumptions, our electric vehicle:
  • will consume 17.5 kWh for the trip
  • produce 40.6 lbs of CO2 (if powered solely by coal-generated energy)
Our gasoline vehicle:
  • will consume 12.62 liters of gasoline
  • produce 64.3 lbs of CO2

Some Codicils

Bear in mind these are estimates.  If the gasoline vehicle were to get closer to 20 MPG, it's CO2 output for the same trip would drop to 48.2 lbs.

There is also the reality that gasoline vehicles and electric vehicles operate almost opposite of one another: whereas an ICE engine increases efficiency as it runs at higher RPMs (such as when driving highways), electric vehicles benefit more from in-town driving (where they can use regenerative braking and are not going fast enough to incur meaningful air resistance).

If our electric is able to run at around 250 watts per mile, its CO2 cost drops to 29 lbs.  A comparable gasoline engine needs to attain 33 MPG to match that.  250 watts per mile is honestly rather low, but it can be achieved (as can 33 MPG or greater).

Conclusion

Bear in mind that all mileage ratings are based on very specific EPA standards, which are designed not to tell you how far you can really go on a tank of gas or a charge, but how one vehicle compares to another given certain standardized conditions.  These can include not running the air conditioning - and for those who live in hot climates, we all know how absurd that expectation is.

If we can power our electric vehicles with energy sources less-polluting than coal, our CO2 footprint drops.  For instance, if all our energy comes from natural gas, the same trip at 350 watts per mile will cost only 16.8 lbs CO2.  To get near that with gasoline, you now need to run at 57 MPGs - good luck with anything but the most fuel-efficient vehicles and the most careful driving!  If we switch to nuclear or renewable sources, game over.

While there is much left to be done to truly make electrics as functionally capable as ICE vehicles, the fact remains that in terms of power-options and their ramifications for the environment at large (which, of course, comes with a ton of assumptions we won't deal with here), electrics are quite literally the here-and-now future.

P.S.

I personally don't drive an electric because of environmental considerations.  I believe the interactions and inputs involved in our climate are significantly more complex than anyone is willing to discuss in open forum.  If we traded out all ICE vehicles for electrics tomorrow, we'd simply have a different set of problems, environmental and otherwise - not the least of which would include untold millions of tons of volatile lithium batteries in various stages of degradation.  Like I said, there is still far more work to be done on electrics, but we should not discount them or mock the people who own them.  There are economic opportunities afoot - the greatest fools are those who refuse to take advantage of them.

There was probably a time with everyone who owned horses scoffed at the new Model T rumbling down the road, and look at where we are today.

20230610

Electric Cars and Coal

 It's funny to me when people talk about filling electric cars up with coal.  Like so many other conversations these days, such simplistic statements and views obfuscate reality.  Are electric cars "no better for the environment than gasoline?"  Should we all go back to internal combustion engines (ICE)?


The Simplistic View

If we just run a few numbers, we can compare powering our vehicle with gasoline versus coal.

In order to have some common basis of comparison, let's say we need 50 kWh of power to drive somewhere.  That's actually a pretty long trip, or a not so long trip on a very hot day.

Sparing the actual calculations for now (the curious can try to replicate my math with some choice web searches), we find that powering our vehicle will cost us in lbs of CO2 as follows:
  • coal: 116 lbs of CO2
  • gasoline: 28 lbs of CO2
  • natural gas: 48 lbs of CO2
So it seems that everyone who is puttering around in ICE vehicles is actually doing the world a favor!  Down with electrics!!


Not So Fast!

Our above calculation assumed that the gasoline was going to the generation of electricity, not to actually driving somewhere.  At best, you're cruising down a highway with your vehicle's engine at optimum efficiency.  At worst, you're sitting at stop-lights and chewing through your gas tank.  Anyone who has recorded their each and every fill-up and mileage can attest that in-town, slow and poke driving is significantly less efficient than highway, and so this wonderful estimate is already highly misleading.

There's also another problem.  A gasoline engine can take only one kind of fuel.  Anyone care to guess what it is?  (Variations on a theme don't count - almost no one fills up on 100% ethanol.)

The Alternative Conundrum

An electric vehicle doesn't care where the power comes from.  That's really one of the beauties of it.  

According to some sources, only 23% of the electricity generated in the United States during 2021 came from coal-fired plants.  The rest were... not coal-fired.  To make the argument that electric vehicle owners "fill up on coal" is like saying that people who eat meat "fill up on Burger King."  Surely we can all see that the not all meat comes from Burger King, and not all power comes from coal.

Let's see what our electric car can use, as opposed to an ICE vehicle:
  • Electric
    • coal
    • natural gas
    • oil
    • nuclear
    • wind
    • solar
    • tidal
    • hydroelectric
    • geothermal
  • ICE
    • gasoline
    • diesel
    • ethanol
    • (propane, if you're driving a forklift)

If we're looking to rid ourselves of dependence on a limited selection of fuel sources, then certainly ICE engines can't compete.


But... The BATTERIES!

Yes, we all know the batteries are environmental disasters.  And what was the Exxon Valdez?  What is it that inspires people to protest and complain loudly to their representatives about on-shore and off-shore drilling, fracking, the transportation of oil via pipelines, oil exploration in general?

The battery situation is not a fixed one - it is subject to the evolution of the technology.  While ICE engines have evolved, their fuel has really not.  It's been made less harmful (i.e. no more lead in our gasoline), to be sure.  But it will always be gasoline.  Even ethanol, which is costly to produce, is not an improvement.  Just think of it in terms of the crops and the environmental impacts of growing them, then the refining, and finally the reality of ethanol's efficiency (or lack thereof) as a fuel.

We have made some great strides with battery technology, but more certainly needs to be done.  Whenever that happens, however, the batteries still won't care where the power comes from.

It should also be noted that the coal mining, the drilling, the fracking, the fuel refining are all very horrible activities, environmentally-speaking.  These don't go away because you're not using coal to power your ICE vehicle.  They're simply built into the price of gas, and cannot be avoided.


Speaking of Batteries...

One of the ironies I realized while typing this post is that gasoline does not have a long shelf-life.  It does go bad.  For this reason, I converted my little generator to use propane.  Propane may not produce as much power output as gasoline, but it doesn't go bad.  However, people don't use propane in their cars.  Sometimes you see it on forklifts.

Power, once produced, can be stored in a number of ways.  Everything from mechanical to chemical, and new methods are being developed every year.  One such recent initiative was taking place in Italy, where a company was developing a "battery" that consisted of a closed-loop CO2-based pressure system: CO2 would be compressed by way renewable energy sources.  The compressed CO2 is stored, then released later through a turbine to generate power.  The released CO2 enters another holding tank, so that it can be re-compressed once renewable energy sources come back online.  This is a kinetic battery, no harmful mining or chemicals required.

In my mind, our biggest inefficiency today is our inability to produce energy optimally.  We currently have to guesstimate our production, and often we overshoot it.  That yields waste.  Any sort of battery system that could buffer the varying load demands could reduce our current generative outputs.  Such systems could also capture significantly more benefit from solar and wind producers. 

Don't Forget Transmission

One other thing often forgotten is that every gas station needs power and fuel delivered to it.  The pumps don't operate without power, and neither do the cash registers or the lights in the station.  So if electric cars are burning coal, so are the gas stations.  The gasoline also doesn't arrive by pipe.  It arrives by tanker truck.  They burn diesel to get it there - a lot of diesel.  When gasoline in an area runs out (such as after a natural disaster), it can take a while for the trucks to get in and refill the stations.

We'll forgo talking about the transport of crude oil, the energy taken to refine it, and so forth.

Electric vehicles take electric power from electric lines.  The lines don't move.  They need no delivery trucks, and whatever power losses are incurred in power transmission, I would not believe them to be greater or even near that spent on tanker trucks.  In a natural disaster, people with solar on their homes or sufficiently beefy generators can still get charged up and go.  There is no need to wait for the gas station to get refilled.  Power lines can last years - possibly decades - without needing replacement.

In Conclusion

All of these options and technologies feed neatly into electric vehicles.  While electric vehicle tech still needs - in my opinion - quite a bit more refinement, it will get there.  But it can only get there if there is a market for it.  No market can exist where people are prevented from buying it, and we shouldn't be denied the option to use alternative energy sources.

Now, I've written all of this and probably sound like an electric car evangelist.  I'm not.  I own an ICE truck for hauling and long-distance travel (and because of having a sufficiently large family - long trips need extra room).  That said, the ICE truck's battery goes dead if I don't run it once a week.  That's how little we drive it. 

I've tried to keep what I've stated above limited to just the facts.  There are many instances where there is overlap between ICE and electric: the costs of drilling, refining, transporting, and burning of fuels for either energy production or to power an ICE engine, tend to be close to the same.  The cost of manufacturing the complex engines, cooling systems, catalytic converters, and so forth are replaced by the costs of manufacturing rare-earth-magnet motors, battery systems, and all the requisite electronics.  It's difficult to say if the cost exchange rate is 1-to-1.  I'm not sure anyone can accurately account for it all, and it's honestly silly to argue over it.  

What isn't disputable is the fact that an electric car offers far more choices in power source, than an ICE.  An ICE will never be able to make use of nuclear, whereas an electric can.  Energy underpins our modern world, and that is a fact that - barring an apocalypse - isn't changing any time soon.  The more efficient we are in transferring and storing it, the more we can do with it.

As a bit of inspiration, I watched a video of a US Congressman's Tesla battery upgrade for his house.  His house was completely off-grid, and he even wired up his Tesla charger to only operate when the sun was out.  When was the last time you could refine your own gasoline when the CO2 production in your local area was minimal?