What happens when millions of
electric vehicles meet the U.S. grid?
by Bob Waterstripe
Electricity consumption in the US is
enormous, over 4 trillion kilowatt-hours
(kWh) last year. That’s 12,068 kWh for
every one of about 334 million
Americans including little babies,
enough power for each one of us to run
a 1,500-Watt electric space heater 22
hours a day for 365 days. Or to drive a
Tesla Model 3 for 50,200 miles (kids can
use the autopilot feature).
Today there are over 2 million electric
vehicles (EVs) driving around the U.S.,
consuming some 7.2 billion kWh, or
0.18% of the electricity used last year in
America. At that rate, it would take over
10 million EVs to use only 1% of that
electricity.
So what happens when we plug 10
million EVs into the grid? Not much —
yet.
However, there are over 280 million
fossil-fuel burning cars, SUVs, and
pickups in the U.S. today. 18 million such
vehicles are sold in the U.S. in a good
year. Now, with major automakers
committing to 100% EV production in
coming years, we will soon see millions
and then tens of millions more EVs
tapping the grid each year. Still, 18
million EV’s would still use only about
1.6% of that 2020 electricity
At 18 million new EVs per year, we could
replace all those 280 million vehicles
with EVs in less than 16 years. 280
million EVs would use 25% of all the
electricity we had in 2020.
The good news — for now — is that the
grid is built to handle peak power
demand, normally in the hottest and
coldest mornings, during business
hours, and in early evenings. The rest of
the time, demand for electricity is lower,
so there is plenty of excess capacity for
EVs if we charge them at night. This
situation can hold us long enough to
replace fossil fuel plants with
renewables and batteries, and to build
the additional clean power generation
capacity we will need.
Total utility-scale power generating
capacity in the U.S. today is about 1.12
billion kW. Theoretically this capacity
could generate overall more than twice
the total electricity that we use today,
although in many areas hot or cold
weather can already strain the grid
during peak hours. The ratio of peak
demand to average demand is some 1.7
to 1.9, depending on the area. In fact,
we would only need about 10% of that
extra capacity for even 280 million EVs
charging at night.
The U.S. Energy Information
Administration (EIA) predicts
2
that
electricity demand will grow by less than
1% per year from now until 2050.
However, even only 1% annual growth
compounds to 35% more demand by
2050. This prediction does not allow for
much growth of EVs and says that
electricity used for transportation (EVs)
will remain below 3% of total electricity
demand even in 2050. Released in
February, 2021, this otherwise brilliant
analysis of our overall energy situation
does not contemplate the now-
inevitable rapid adoption of EVs.
Besides building 35% additional
generating capacity needed by 2050, or
more for all those EVs, we also need to
replace existing fossil fuel sources that
account for 66% of our power today
(20% coal, 43% natural gas, 3% oil) with
clean solar and wind. Today, renewables
deliver 25% (16% non-hydroelectric, 9%
hydro-) and nuclear provides 9% of our
total power.
I conclude that one way or another the
existing grid can power as many EVs as
we can build, while we convert our
electricity output to zero-carbon and
add capacity for the future. People in
most areas can take advantage of the
economic and environmental benefits of
EVs as fast as they are produced.
As for building a zero-emission grid, the
fastest way to add clean power is solar.
The cheapest way to add clean power is
rooftop solar on homes, businesses, and
carports. This is called “distributed
generation”.
When a utility goes solar, the customers
pay for the solar power plant, then they
pay for the power forever. When you
add solar to your home or other
building, you pay once and get decades
of free energy in return. If you have
enough solar to cover the needs of the
home and your EVs, too, this can
amount to hundreds of thousands of
dollars in long-term cash savings.
Using solar to offset your home’s electric
bill is great, but the same amount of
solar eliminates more emissions, and
saves a lot more money, when you
power your EVs and avoid the emissions
and the cost of burning gasoline or
diesel.
References:
https://www.eia.gov/outlooks/aeo/pdf/A
EO_Narrative_2021.pdf
https://www.eia.gov/energyexplained/el
ectricity/electricity-in-the-us-generation-
capacity-and-sales.php