The nation is getting its head around all-electric powered cars by 2035. It sparked me -haha- to wonder if electric cars really generate a carbon footprint smaller than gas-driven cars. My research confirmed it: in a “well-to-wheel” comparison, an electric car generates about one-third the level of carbon compared to the gas guzzler. So case closed on that.
But what troubles me is the generally held notion that we will just plug our car into an outlet every night, and be ready to drive by daylight. Where is the electricity coming from? That is a thornier question, and it doesn’t appear to have a satisfactory answer yet.
Here are some numbers worth knowing.
- The US annual consumption of electricity in 2020 was 3,800 Twh. A ‘Twh” is a terrawatt hour. Because I know you really want to get into this, a terawatt is one trillion watts. That’s with 12 zeros.
- The US annual production of electricity for the same year was 4,009 Twh.
Understanding these two numbers, you see we have a margin, say, a surplus of 209 Twh. Just for fun, that’s 209,000,000,000,000 watts.
What is interesting though is that the US also sells and buys electricity during the year, based on peak demands and capacity levels. But net, we imported 47 Twh last year. So we did not actually have enough to go around, based on our own production capacity.
Not having enough is generally a foreign concept in America, but there you have it.
So: will we have enough electricity for the car in our garage come 2035? That troubles me. Here’s why.
In 2016, American automobile mileage was 3.22 trillion miles. We are “trillionaires” for everything, it seems. Assuming that electric cars replace all the gas guzzlers, and that we still drive the same distance, happily guilt-free of carbon fears, will we have enough electricity?
I am not so sure. Tesla’s 2018 Model 3 has a commendable “mileage” rating of 26Kwh. That is, it can drive 100 miles using only 26 kilowatt hours of electricity. This is the best there is, today, beating out the Chev Volt, VW Golf, and BMW i3. By the way, 26Kwh is the equivalent of burning a 40-watt light bulb over your stove for 27 days. Doesn’t seem so bad, really.
But the total mileage of 3.22 trillion divided by Tesla’s 26Kwh/100 miles will require a total of 837Twh of electricity. That’s additional energy over what we use today. And we only have a margin of 200Kwh.
We do get one break. By shutting down the unnecessary gasoline refineries, we will save 47Twh. So our actual new requirement for electrical power is only 790Twh. That’s 790,000,000,000,000 watts.
Meanwhile, the State of California is enduring periodic black outs. Why? Because in the effort to be a good environmental steward, they have been closing their coal and nuclear power generating stations in favor of wind turbines, solar and hydro-electric power, aka, power dams. Unfortunately, when there is no wind, no sun, and no water, there is no power. Local cynics refer to the disruptions as ‘Green Outs”.
It turns out that the engineers in public and private sectors have been noodling on this. Some of the more common solutions are wind turbines. Did you know that today there already 67,000 turbines thrumming the winds in America? And solar panels? There are 2,500 such farms today. Of 80,000 dams in the country, some 2,400 are hydro-electric power generators.
These solutions generally fall under the heading “renewable energy” sources. In total, renewable energy supplies 20% of all the power generated in the US.
There is another solution which is being developed, and that is the reversible battery charger. It allows for energy to flow both ways from your electric car. You might plug it in for one night last week to charge for six hours, and then you left your car undriven, and cooling in the garage for several days. During that time, if you have a permit, the power company may take electricity back from your car to top up the grid. You would get a credit, and maybe an empty battery, but you would be a good person.
The lack of surplus electrical energy is not top of mind for many right now, but as we approach the next decade, the subject will arise much more frequently. Stay tuned, and as usual, turn out the lights upon leaving.
Thanks for reading and sharing! Will you get an electric car? Will you get the charger too?