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Aren't hydro-batteries more popular and efficient than rail storage to store energy as gravitational potential?

Train storage is the only gravity-powered battery? Well, dam.

Another type of gravity storage involves pumping water uphill and storing it behind a dam. Then, when needed, releasing it through turbines to generate power on-demand.

I recall a college Economics class back in the 1980's. The topic was a lake in the Alps, created by a dam. During the day, they drained the lake and generated hydroelectric power, and during the night, they ran those same impellers in reverse and pumped the water back into the lake. Our instructor asked us, "How could this possibly make economic sense?" (Students: Blank looks.) Well, electricity was cheaper overnight when most of the households were asleep and factories quiet, and more expensive during the day with everyone going about their business in homes, factories, offices and schools. So it earned money during the day generating the power, and cost far less overnight "recharging the battery" overnight and consuming power. I was surprised at that.

You missed pump-stored hydroelectric, a technology that's already used in a couple places and is very efficient.

"modern flywheels use space-age materials like carbon fibre composites and spin in a vacuum, while levitating on superconductive magnetic bearings" That sentence is so sci-fi 😂 love it

What about filling a room with treadmills and kids , waiting until you need power , then supplying the room with red bull and brownies.

I can't tell whether he used "capacity" instead of "power", or use "MW" instead of "MWh". Either way, that is wrong. And the video missed pumped hydraulic storage, which is already in use now. And lead-acid batteries are not "bad for the environment". They work for many years without releasing any chemicals at all, and at the end the lead is easily, economically, and totally recycled. They are just more expensive, per capacity, than some of those other alternatived

Thank you for having captions right away! Us HoH and Deaf viewers appreciate it

Great video! The first part really had me pumped! I was bursting at the seams! The second part was quite the thrilling roller coaster with all the ups and downs! That last part put a real nice spin on the whole piece!

Something about Michael's presentation skills makes his videos seem really short. Love it!

At 3:00 "With a capacity of about 50 MW ..." - what you mean by "capacity"? MW is unit of power. Energy storage capacity is usually measured in energy units.

Great video! You seem to have made an error. You talk about capacity in units of Watts which... simply doesn't make sense. Please do not add to common confusion about electric power and energy and use the right units

In case someone is wondering why carbon fiber, something light, is a good material for storing rotational energy. It's because kinetic energy of a system increases with the square of velocity and only half of its mass. Carbon fiber has a high ratio of tensile strength to mass, allowing it to spin really fast, making up for any loss of it being so light by being so fast.

- This video needs to be 10x longer. Modern techniques of compressed air storage account for the problem with heat loss and bring that efficiency rating up to 70-80% (Adiabatic CAES). - Then there's also LAES with an efficiency of 60-75% BUT it can be placed anywhere. No caves, inclines, dams, or super expensive facilities needed. - Flywheels are no good for massive grid storage. They're not only price prohibitive and dangerous if things go wrong, but they don't scale up the way other storage solutions do. They're good for small systems. Not for powering a city. - Then pumped hydro. This is a pretty big one. Very great tech that's in use today. Location prohibitive, and also not ideal for the environment since you need to potentially wipe out an ecosystem to build one. But a great tool to have along with the others (except flywheels, so far) this is a topic I hope to see many more videos about. Not just from you but from all KZfaqrs

2:52. Man, you triggered thundef00t. In fairness, the train storage seems to be more practical than the crane one: simpler and less problem of wind.

you can also wind or solar to pump water to fill a reseviour amd then use hydro

0:56 Talking about pneumatic tools, shows electric breaker.

One gravity battery you didn’t mention: hydro! Turbo-generators can work in reverse and pump water uphill for use later.

Love that you measure stored energy in watt and not joule or watt-hour like a normal person, and, you know, they are actually units of energy, not power

Regular flywheels don't seem to be a bad idea for "power shifting" solar power. Spin it by day, let it rip by night. The 20% per day won't be much of an issue here, as you're only needing the power some hours later rather than a whole day.

A big one you missed is pumped hydro which Australia is spending a bit of money on at the moment.

"Capacity" in Watts? C'm on guys, you can do better than that.

You guys should have included the gravity storage option where they raise and lower a huge weight in a mine shaft or purpose drilled hole. It's almost a combination of rail and flywheel storage.

Let's pressurize a chamber underground... yea, that's a great idea lol

"That main gravity storage" - forgets dams are a thing.

I spent all the the 2010's developing and building large scale energy storage for grid applications. I reviewed under NDAs probably every technology described here, a total of over 200 different companies by the time I retired last year. For the next few years the answer is definitely lithium based batteries. Billions in investment has lowered costs and improved reliability to the point where my latest projects were paying ~$125/kWh for battery modules in the ~50MWh quantities. ~90% efficient, very low standby losses, and extremely compact. Also, the primary companies here (Samsung, LG, BYD, CATL, Tesla, etc.) are large companies that can financially back long term warranties, which is a real requirement for storage projects that can cost 10's to 100's of $millions. There is a need for longer term energy storage, and that is an ongoing area. Compressed air would be great, but the problem of extracting the heat of compression during compression, storing it, and then reinjecting has been one several smart companies have tried and failed at. Aside from the "train" noted here, there are many non-water gravity storage systems, but few if any can provide needed services at a low enough tech risk and cost. Flywheels have made great strides, but stand by losses are too great to bear, and Li batteries now beat them at $/kWh by a wide margin. Also, the edge of a grid storage flywheel may be traveling at equivalent to Mach 2, and if the mag bearings fail, the sudden energy release is a sight to see. As many people noted, pumped hydro storage is a mature tech and widely used around the world. the USA hasn't built any new pumped storage in about 30 years, but that's mostly because of the politics of water in the Western USA. China was under construction on 20GWh of pumped storage a few years ago. I believe a lot of current efforts for long duration storage are about creating some energy-dense chemistry using off-peak wind and solar, such as H2, Methane, Ammonia, etc.

I can think of a combination of fly-wheel, air *&* Gravity. The Wheel is at the Base. It is horizontal. From it center, going up, you have what amounts to a sack, the top is heavy. The center is a poll to keep it standing, as well as let air enter from the top, and out through the bottom, to accelerate the wheel. In hear you actually want the air to cool while at storing mode, and heat while releasing power. A fairly easy way to do that. Having the sack be multi layered. The inner sacks being heat conducive. Thus the air cools, and there's room for more. When the fly wheel slows, the outer sack slows too. The heat sink for the inner sacks is capped (the minimum speed keeps it of, slower, capped) By slowing it's weight raises the pressure. Some of the power made by the wheel is used to heat the inner sacks. This raises the pressure. So the air coming out, is speeding the wheel.

2:50 Thunderf00t made a video about that called: Energy Vault -BUSTED!

Water pumps instead of air pumps, put a solar panel on a fountain pump. Pump the water uphill or into a tank Have a gate/valve, open as you need it, and use turbine power generation as the water falls back down. (there's even a means for capturing energy from falling water using magnetic flux, if you wanna get fancy)

There's another example of a battery here in the UK: two lakes, one situated far higher than another. When there's a surplus of energy, water is pumped from the lower lake to the upper lake, and the water flows down when they need to syphon energy.

Are we about to learn about flywheels?

In Missouri, we have Tom Sauk Reservoir. It dumps it’s water through the dam whenever power demand gets high in the heat of the day, and then at night water is pumped into the reservoir for the next day.

2:50 I bet you if an artist made a moving sculpture out of the weights it would not only look awesome it would bring more attention to reusing this old technology.

We had to design a mechanical battery as part of our senior design project in college. One of the downsides they didn’t mention is the enclosure required around the flywheel. To get the most energy storage out of the wheel the speeds are in the range of 30000 rpm and you have to worry about the wheel bursting.

Awesome video. I hope we renewable energy here pretty soon. I learned a lot watching this.

Personally, I wish there were more interest in developing nickel-iron (edison) batteries for utility-scale energy storage. Really old technology with a low energy density, but they're made of inert, safe materials and they last for ages.

What about pumping water uphill behind a damn then releasing it when needed.

"Regenerative braking". Thank you. Finally. I've been looking all over if cars use their potential energy when descending to recharge their batteries.

Just so happens that i watched Tom Scotts video about a related topic just earlier lol :)

That limestone cavern is under my home town. They've been talking about using it for energy storage for probably 30 years, originally using water. Lots of studies, not a lot of progress.

My first thought of "physical batteries" was a giant spring being compressed by electricity.

Always a pleasure to hear his mellow voice

Compressed air storage and the heating problem use vacuum insulated water storage tanks, the heat from compression is transferred to the water you can augment this further by having solar water heaters on the facilities grounds and rooftops. edit electrical solar panels being dark heat up rapidly and work better when cooled yet another synergy that can be used.

I loved this video. Thanks for videos like this one.

I always find it interesting how often overlooked one of the most common mechanical batteries is, granted this is probably because most people see it as a form of energy generation, not storage, but strictly speaking hydroelectric reservoirs are giant stores of energy, thus making hydroelectric dams lake sized batteries

Another few issues with flywheels: 1. Like dams, Catastrophic failure projects their energy output straight in bad directions. 2. If they're not aligned with the Earth's rotation, they will lose energy unless they can keep their alignment independently of the Earth.

centrifugal force limits energy storage capacity of flywheels by limiting rotational inertia. flywheel explosion occurs when a certain linear velocity is exceeded at the circumference of the flywheel. composite materials can bare higher velocities compared to steel. there are recent scientific studies on this subject. (yes in germany:) besides magnetic bearings, electromagnetic clutches are also needed for flywheel energy storage. I was searching em clutches from stromag and keb for my project. I saw in one of these catalogs a flyeheel storage tecgnology product (probably keb's) there was also a company dedicated to this tech. (don't remember the name) daylight excessive solar energy production is stored in a flywheel in this company's technology. I hope this comment might help on the subject.

This is an awesome video great work man

I believe the Williams F1 team were looking into the flywheel battery around the deployment of the original ERS / KERS systems too

Compressed air, powers things like jackhammers (clip of electric jackhammer being used)

If you know anything about supply chains, you know it's generally considered a good thing to have a minimal amount of inventory acting as a buffer, since it inevitably slows the whole system down and makes it less efficient. Power is the same way. If we need to store energy for when supply cant keep up with demand, it probably isnt a very good solution on large scales, in this case, for cost reasons. This makes things like nuclear and hydro power vastly superior, since an energy "inventory" doesnt need to be maintained. Like fossil fuels, power output can be scaled up or down as needed, since we have full control over the output of these types of power plants at all times.

Michael is the best!

The rail energy storage animation showed a steam locomotive! Such systems actually use electric traction: electricity in, electricity out. The illustration should have been an electric locomotive. Although they are more likely to use only rails to conduct the energy, it would be clearer to show the technology with overhead catenary.

Those flywheels sound useful. Maybe they could be put to other use on the side? Perhaps sorting atoms with different masses?

One of the first US mechanical batteries was Candlewood Lake In CT. It was used to store water for off-season power generation for nearby NYC. The original scheme would fill the lake when water was in excess and drain it when it was needed would cause the lake level to vary. This is not very popular now as a lot of people live on the shores of the lake and it is used heavily for recreation; thus, though the power generators are still used today, they act less like a battery then they used to.

The UK uses a water tower gravity battery. In order to have quick energy to cope with sharp increases in demands after certain TV programs, they store store water in towers and have a person monitoring the programs. Once one is concluded, they flip a switch to send the water through a turbine and feed that local part of the grid. It is faster to ramp up power than the power plants and can focus on certain regions based on demographics.

"Flywheel batteries are pretty expensive" later "clean CHEAP and reliable energy sources like these......"

Gives me hope for future generations.

An uncommonly associated use of flywheel energy storage is dumping the clutch while you are moving to restart your engine after it stalls out

My favorite retro energy storage is called pumped hydro. Its similar to the railcar example but using pumps to raise the elevation of water and then turbines on the way down similar to hydroelectricity. High round trip efficiency as well since it is based on pump and turbine efficiency which we have nearly mastered.

Cole mines used to use compressed air to run everything. Its kinda a cool process. Hydro electric dams are involved. Its crazy engineering.

We could also use steam power for electricity generation better by using water in a vacuum in a closed-loop system only needing 30c rather than 100c to boil a significant reduction of energy requirements and as the expansion rate is the same no matter how you boil the water the same energy generating potential exists as in standard steam using systems. Solar water heaters could be the new solar cells and water tanks as batteries for most of the world.

This is an awesome video!!

Don't forget about pump storage. Duke Energy uses a man made lake and dam. During the night, they pump water up a mountain to this lake, then at high usage times, they let it back down through a few stages to generate energy through turbines.

How on Earth can one not mention Hydro storage, they're the biggest batteries on Earth, BY FAR. It seems like a huge oversight from the writing team this episode.

One of the best is probably the one where you pump water uphill and then let it flow out into a lake when u need energy

Sounds like flywheels would work great in space

It's really amazing how much energy we use just to heat and cool things. Imagine if we could find a way to use heat pumps to transfer heat efficiently and effectively to where it's needed rather than burning fuel to accomplish the same task. The issue seems to be transmission. Infrared radiation would just get absorbed, and brownian motion requires a contact point or heat exchanger of sorts. Essentially we do this everyday by using an intermediate like electricity, but conversion losses lower it's efficiency. We use energy to generate power to run an air conditioning system, and we heat living spaces where the climate is too cold. To put it simply: I wish we had a better solution.

There is another gravity assist "battery" that is being used successfully in Europe and Japan: pumped-storage hydroelectricity. The idea is that you use renewable but intermittent energy sources -- wind and/or solar -- have some power diverted to pump water into an elevated reservoir. This mass of water in a high potential energy position effectively stores the generated electricity. When the intermittent energy is too low to fill the need, water is drained from the reservoir through electricity generating turbines, exactly like hydroelectric power production.

The UK grid water-powered gravity fed works a charm.

Reminds me of the excellent novel by Paolo Bacigalupi, _The Windup Girl._ It's a postapocalyptic book after global warming and the depletion of fossil fuels, leading to "energy wars" which devastates the world already suffering from rising sea levels, plagues, and famine. In the novel, one of the main technologies are "kink springs" which are basically windup springs that store elastic energy. They are "charged" by animals turning a wheel or people pedaling a bike. It converts calories from food into energy that can be used by machines.

I could see the compressed air one working on large scales

You forgot another ancient battery tech that's already being used, water storage. It scales up better than compressed air, it has decent round trip efficiency and is already an established way to store energy for peak times of demand. Besides,it also creates recreation, economic, and ecological opportunities that would otherwise not be available.

I also like pumped-hydro storage. Those systems are in use today in a few locations so it's a proven technology, and it seems like more could be relatively easily. I think they have problems too (land area used) but nothing perfect and I think their efficiency exceeds 80%. As for retro, it's as old as the water wheel.

Solar and wind, renewable energy that uses unrenewable materials. Sounds great!

You could cover using pumping water into dams up hill and releasing the water when the power is needed. England has been using this method of years.

Did you forget about pumped-hydro?

Yes, make a giant pressure pot, those have never exploded before.

There seems to be pretty smart people here. Would some of you mind helping me out? This may be a dumb question, but I’m actually curious. Why don’t we just make giant springs and wind them up to store energy? Other than the risk of catastrophic failure, I’m unsure of why this wouldn’t work. It seems like it would be fairly cheep just a long coil of steel or something and you’re good to go.

Science fiction used to be fond of having municipal buses powered by flywheels. And regarding gravity-based power storage - you left out pumped water, which is widely used.

I think water pumping is worldwide the #1 source of energy storage. It has a round trip efficiency of less than 80% but it's probably the cheapest to make.

I love this topic, thank you for your hard work

Oooooooor we could just go more Nuclear

I did a research paper in grad school for the energy storage systems class I was taking on flywheel energy storage systems. Honestly, SciShow could do a whole show just on flywheel energy storage systems. All the grad students were required to give a 5 minute presentation on the topic. I was had to go rather fast to be able to fit it all in the allotted time. just food for thought

the train stuff was neat, but i think pumped hydro would be considered large scale, and also gravity powered.

The Pink Bunny returns beating his drum.

I can't believe you talked about flywheel without mentioning those handcranked flashlights! Those have existed for over a century.

What about gear spring or mainspring technology?

I am surprised that they didn't cover pumped hydroelectric storage. It's not quite as old, but has a lot of potential, especially the underground weighted piston type which could to remove the geographic limitations.

A surprisingly interesting and informative video.

Dinorwig power plant uses water, pumps the water up when there’s an excess and uses the water to turn a turbine on the way down using gravity ~70-75% efficiency and produces 9.1 GWh according to wiki

Best channel ever. Keep up the great content.

I had a dream about this concept last night, weirdly. More using water pumped up-hill then letting it flow.

there is a bus that ran using a flywheel. I think at some of the stops they had induction coils to power a motor to reup the flywheel energy.

And for the house-hold use ..Anything!

Flywheels used as backup power in CERN where loss of power can cause beam go straight instead of bending and make a hole in expensive equipment

Years ago I had the thought of a combination storage device for a bicycle that was a heavy disc and batteries. Simply before getting on it, or during riding, you could rev up the disc or start with charged batteries since the energy has to start somewhere, and put very little effort into keeping these 3 energy sources bouncing around. Sound crazy or am I missing something?

Oh, I thought you'd use the maxim: "Everything old is new again" :)