- Batteries make a lot
of modern tech possible. Everything from cell phones,
cameras, medical devices, a million appliances, to bigger
things like electric cars. You might get frustrated because your cell phone still
can't make it through the day on a single charge, but the fact is, battery technology as a
whole is leaping forward. It's improving so much that batteries aren't just powering
our phones and our cars, they're powering cities and even replacing entire power plants. But storing energy on the
power grid isn't a new idea. In fact, batteries are joining some really whimsical technology. Tech that might make you wonder what the definition of
a battery actually is. (light music) - Well, storage has been
sort of the Holy Grail of the electric grid
or electricity industry for a very long time, decades, really. - [Cory] JB Straubel is a
co-founder of Tesla and its CTO. Tesla, obviously, is big into
batteries for their cars, but they're also tackling
city-sized energy storage, which improves on our
very old school grid. - You know, the electric
grid hasn't changed that much from 100-some years ago
when Tesla and Edison were actually inventing it. Most people don't realize, but it's instantaneously matched. Every time that you turn on
a light switch in your house, instantaneously, a power plant, somewhere, connected to that same grid, has to ramp up a little more power output to make the light operate. - When you turn on that light, you're probably relying on a big old gas or coal fired plant. Fossil fuels account for about 60% of electricity in the U.S. and another 20% comes from nuclear. Big plants are steady, but
they're not very flexible. - Generally, to power something, you have these huge base load gas plants. - [Cory] That's The
Verge's own Angela Chen. - And these are running
kind of all the time, no matter what and they're pretty slow and you can't really adjust how much energy they're creating. - When demand is too low, these big, slow plants
actually lose money. And when demand is too high,
quicker, dirtier plants called peaker plants have
to switch on to keep up. And they're pretty wasteful. - So you kind of get dinged on both sides. You get dinged when you
don't have enough load and then when you have too much, you also get dinged inefficiently. - So, traditional plants
aren't super efficient, but they're consistent
and therefore predictable. Renewable energy can be another story. Solar and wind power is cheap
and clean and plentiful, but only when the sun is
shining or the wind is blowing. - So, inconsistency is the big worry, that, you know, it'll be a cloudy day or it'll be a still day
and then all of the sudden, your appliances won't work
and that's something that no one really wants. - What makes batteries so promising is that they can solve
all of these problems. When paired with big power plants, they can supply energy during peak times without polluting the way
that peaker plants do. And when paired with renewables, they can jump in when clouds
roll over a solar farm. Energy storage really is the
missing piece of the puzzle for renewable energy. But when we say storage, we don't just necessarily mean these. On a super broad level, a battery
is like a bank for energy. You deposit energy into
it when you don't need it and withdraw it when you do. We use electrical energy on the grid, but we can store it as any kind of energy. Exhibit A: the Hoover Dam
is in the news right now because of plans to turn
it into a giant battery. It would work by converting
excess electricity into gravitational potential energy. - So, essentially, you have two lakes. There's one at the bottom
and there's one at the top. And then, when the energy is cheap, you can pump water from
the bottom to the top and it kind of just stays
there in the reservoir. And then when you need the energy, you open up the reservoir
and the water goes crashing down and it turns this turbine and it creates this extra energy that you might need for high demand. - This is called pumped
hydro-electric storage and it's actually in use
all over the country today. But there are other options. Flywheel storage works the same way that this little toy car does. Engineers use power to start
a heavy flywheel spinning and that power gets stored via inertia. You can later harvest that inertia to generate electricity again. And weirder still is
compressed air storage. Cheap power is used to
force air into a cavern or a canister, building up pressure. When power gets pricey or scarce, you can release the air to spin a turbine and power a generator. But then, there's the big newcomer. Gridscale chemical batteries. In the past few years,
the price and durability of batteries have improved fast, making them suddenly useful for variable energy sources like solar. - That was kind of
unheard of 10 years ago. If you told someone that,
hey, a lithium ion battery could do that sort of
duty, storing solar energy every single day for 10 years, they wouldn't have believed it. - Batteries are still a tiny fraction of the energy storage market. This is roughly the market
share that pumped hydro waves. And this is everything else. But within that everything else, batteries are growing fast, partly because they work at any size. - Well, I think the biggest
thing is scalability. Batteries have this beautiful ability to vary economically,
scale from gigawatt hour size of systems all the way
down to 10 kilowatt hours in your house. - Batteries do have their weaknesses. They degrade over time,
which you've probably noticed about your cellphone. And you can't run them indefinitely the way that you can a fueled power plant. Once the charge is depleted, that's it. But their flexibility sets
them apart from pumped hydro which is really only practical
on the scale of a lake. The point is, big batteries let us do a couple of exciting things. They let us spread out the responsibility of getting power to where it's needed. And they help patch together
the mixed bag of power sources that we're juggling right now. - I think what you're seeing now is you used to have an entire city would be powered by, you know, two or three huge power plants. And now you're seeing
it's more distributed, so there's definitely a role we can have some of your energy from solar, some of your energy from the grid. It doesn't have to be one or the other. - Of course, the dream of green energy isn't a mix of fossil fuels
and other technologies. It's 100% renewables like solar and wind. But if we're going to go all the way, we're going to need a lot more batteries. Hey everyone, thanks for watching. If you liked this video, please be sure to check out all the other
videos on our channel and don't forget to subscribe.
(deflating) - Yeah!
(laughing) - So good.
- That was great.
Hopefully to get all those batteries we can start to recycle the old ones. It will bring costs down and as he said “cheap for mass market”
JB has gotten bigger...