How much electricity does it take to power the world?
You flip a switch.
Coal burns in a furnace,
which turns water into steam.
That steam spins a turbine,
which activates a generator,
which pushes electrons
through the wire.
This current propagates through hundreds
of miles of electric cables
and arrives at your home.
All around the world, countless people
are doing this every second—
flipping a switch, plugging in,
pressing an “on” button.
So how much electricity
does humanity need?
The amount we collectively use
is changing fast,
so to answer this question,
we need to know not just how much
the world uses today,
but how much we’ll use in the future.
The first step is understanding
how we measure electricity.
It’s a little bit tricky.
A joule is a unit of energy,
but we usually don't measure
electricity in just joules.
Instead, we measure it in watts.
Watts tell us how much energy,
per second, it takes to power something.
One joule per second
equals one watt.
It takes about .1 watts
to power a smart phone,
a thousand to power your house,
a million for a small town,
and a billion for a mid-size city.
As of 2020, it takes 3 trillion watts
to power the entire world.
But almost a billion people don’t have
access to reliable electricity.
As countries become more industrialized
and more people join the grid,
electricity demand is expected
to increase about 80% by 2050.
That number isn't the complete picture.
We'll also have to use electricity
in completely new ways.
Right now, we power a lot of things
by burning fossil fuels,
emitting an unsustainable amount
of greenhouse gases
that contribute to global warming.
We’ll have to eliminate
these emissions entirely
to ensure a sustainable future
for humanity.
The first step to doing so,
for many industries,
is to switch from fossil fuels
to electric power.
We'll need to electrify cars,
switch buildings heated by natural gas
furnaces to electric heat pumps,
and electrify the huge amount of heat
used in industrial processes.
So all told, global electricity needs
could triple by 2050.
We’ll also need all that electricity
to come from clean energy sources
if it’s going to solve the problems
caused by fossil fuels.
Today, only one third of the electricity
we generate comes from clean sources.
Fossil fuels are cheap and convenient,
easy to ship,
and easy to turn into electricity
on demand.
So how can we close the gap?
Wind and solar power work great
for places with lots of wind and sunshine,
but we can’t store and ship sunlight
or wind the way we can transport oil.
To make full use of energy from these
sources at other times or in other places,
we’d have to store it in batteries
and improve our power grid infrastructure
to transport it long distances.
Meanwhile, nuclear power plants
use nuclear fission
to generate carbon-free electricity.
Though still more expensive
than plants that burn fossil fuels,
they can be built anywhere
and don’t depend on intermittent
energy sources like the sun or wind.
Researchers are currently working
to improve nuclear waste disposal
and the safety of nuclear plants.
There’s another possibility we’ve been
trying to crack since the 1940s:
nuclear fusion.
It involves smashing light atoms together,
so they fuse,
and harnessing the energy this releases.
Accidents aren't a concern
with nuclear fusion,
and it doesn't produce the long-lived
radioactive waste fission does.
It also doesn’t have
the transport concerns
associated with wind, solar,
and other renewable energy sources.
A major breakthrough here could
revolutionize clean energy.
The same is true of nuclear fission,
solar, and wind.
Breakthroughs in any
of these technologies,
and especially in all of them together,
can change the world:
not only helping us triple
our electricity supply,
but enabling us to sustain it.
