If you look at a map of the US power grid, it looks like a spider web blanketing the
entire country.
It’s a patchwork that formed after communities that got their power locally were slowly stitched
together to create a massive network.
So could we scale that up even bigger?
Could we connect the entire world with power lines?
What would that do for us, and what would it look like?
The most obvious technological hurdle is transmitting power over extremely long distances, which
is something of a recurring theme.
Back in the 1880s, when the first power plants were coming online, Nikola Tesla’s alternating
current duked it out with Thomas Edison’s direct current in the war of the currents,
the original AC/DC.
Alternating current means the electrons in the wire reverse direction rapidly, while
direct current provides a steady stream of elections.
AC eventually won out because at the time it was easier to convert AC power to higher
or lower voltages, and higher voltages are needed to travel longer distances with less
energy loss due to resistance.
Direct Current has another disadvantage.
At higher voltages, DC could only be used to send electricity from Point A to Point
B. It couldn’t form the sprawling integrated grid networks we need for a stable electricity
system.
So in this match, it’s Tesla - 1, Edison - 0.
But fast forward to the present day, and DC is making a comeback.
Not just because it’s everywhere, since our phones, laptops, and anything with a battery
runs on it.
It’s also because it’s become a more viable method for long distance power transmission,
thanks in large part to China’s geography.
Most of China’s population is concentrated in the eastern part of the country, more than
2,000 kilometers away from most of the country’s sources of coal in the northwest and hydroelectric
power in the southwest.
Typical AC power lines with a voltage as high as 765,000 volts have a max transmission distance
under 500 kilometers.
To generate power in one place and send it across the country, the voltage would have
to go up.
So the government-owned utility State Grid of China collaborated with experts in high
voltage power transmission, like German company Siemens and the Swedish power group ABB, not
to be confused with the other Swedish power group, ABBA.
Soon State Group surpassed the other companies and started developing their own high voltage
transformers and power lines.
In 2009, they built a million volt AC line, and in 2010 they built the world’s first
800,000 volt DC power line.
By the end of 2017 they had 21 ultra high voltage lines crisscrossing the country, and
they’re thinking even bigger.
Right now they’re constructing a 1.1 million volt transmission line that can carry the
output of 12 power plants 3,200 kilometers.
Couple that with ABB’s development of high voltage DC circuit breakers that can allow
for a grid structure and Siemens’ claim that DC lines cost less than AC lines over
a certain distance, and you’ve got the foundations for a global grid and a Thomas Edison comeback
for the ages.
That would allow for some pretty nifty tricks, like taking energy from solar panels that
are in a part of the world that’s sunny, and zipping it to other parts of the world
where it’s dark.
It could actually make renewable energy that’s generated in remote areas more viable.
It’s not that outlandish, in 2016 the US actually had plans to send wind energy to
Tennessee that was generated in Oklahoma.
Why Oklahoma?
Because that’s where the wind comes sweeping down the plain.
Showtunes aside, State Grid even claims a global grid could harness wind power generated
at the north pole and solar energy generated at the equator.
And if it’s DC, we could ditch those AC/DC converters your electronics need that get
all hot and waste about 1/5th of your household’s energy.
A global DC grid is a green dream!
Will it ever happen?
Almost definitely not.
The cost would be astronomical, over 50 trillion dollars, and the politics are way too messy.
Control of a country’s power grid is a major national security issue, and any entity that
built, owned, or operated another country’s power supply would be extremely… um… powerful.
So a global grid is a really cool idea… that’ll probably never happen.
Resistance is a big problem in energy grids, but superconductors could solve that, Maren’ll
tell you all about them here.
Though a global grid is unlikely, State Grid has signed a deal with companies in Japan,
Korea, and Russia with the goal of creating an Northeast Asian “super grid.”
Think it’ll happen?
Let us know in the comments and subscribe while you’re down there.
Thanks for watching Seeker!