Gravity Storage 101 Or Why Pumped Hydro Is The Solely Remotely Actual Gravity Storage

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In my latest article celebrating the nice month that pumped hydro had, between the Loch Ness Crimson John facility promoting to Statkraft, the UK lastly selecting cap and flooring for the expertise and China having 365 GW of energy and 4 to eight TWh of vitality storage underneath development, I included a throw away line.

As a reminder, pumped hydro is the gravity storage answer that really works, not like concrete blocks, elevators and hillside rail programs.

This triggered the entire individuals who assume Vitality Vault has a remotely wise expertise and the tiniest likelihood of delivering something of worth, the individuals who just like the ARES rail-based gravity storage nonsense and possibly those who assume unused workplace elevators, water towers, and mines and large piles of sand are an enormous supply of untapped storage as nicely.

So it’s time, as soon as once more, for the fundamentals and a bunch of examples so that individuals can cease fantasizing about elevator, cranes or trains and concentrate on water and present hills as a substitute.

Let’s begin with the fundamentals of the physics. Gravity storage works due to potential vitality. That’s merely a mass increased up. Because it goes down, the potential vitality turns into kinetic vitality, the vitality of motion. Because it goes down, we are able to harvest that vitality. It takes vitality to maneuver the mass upward, and may get various levels of vitality again from it on its method down.

That is all topic to the legal guidelines of thermodynamics. Let’s use British creator and scientist C.P. Snow’s model:

• You may’t win (that’s, you can’t get one thing for nothing, as a result of matter and vitality are conserved).
• You may’t break even (you can’t return to the identical vitality state, as a result of there’s at all times a rise in dysfunction; entropy at all times will increase).
• You may’t get out of the sport (as a result of absolute zero is unattainable).

What meaning is that if you happen to put 100 MWh into an vitality storage system of any sort, you’re going to get lower than 100 MWh again. That’s often vital, however not with vitality storage programs that aren’t pumped hydro utilizing present hills. There’s no method across the three legal guidelines, there’s no reinterpretation of them that lets them be sidestepped (as one remark I noticed just lately mentioned for his or her expertise) and everybody has to play by the identical guidelines.

Okay, so it’s vitality and we’re going to get much less out than in. How can we determine how a lot vitality? That’s simple. Multiplying the mass occasions the pressure of gravity occasions the peak will get the potential vitality, the utmost quantity you may get again. That’s in joules, which isn’t useful for the common one who by no means makes use of joules, however one million joules is 0.277778 kWh. The opposite method round, a kWh has 3.6 million joules.

As a result of that is metric, we use meters, kilograms and gravity is measured in meters per second squared, 9.8 of them to be considerably exact. Let’s begin with a hypothetical scenario, a one metric ton or thousand kilogram block we transfer up 100 meters. Good spherical, easy numbers.

1,000 kg * 9.8 m/s^2 * 100 m = 980,000 joules. That looks like an enormous quantity, however that’s solely about one million joules which implies it’s equal to about 0.277778 kWh.

A Tesla wants about 14.4 kWh to journey 100 kilometers, so this one ton block transfer up 100 meters is sufficient to drive a Tesla slightly below two kilometers. One other method to think about it’s that it is sufficient to boil a pot of water.

For these unfamiliar with metric, that’s near the size of an American soccer subject however straight up and a couple of,200 kilos. To boil a pot of water. Electrical vehicles are actually environment friendly.

Okay now that we’ve the fundamentals, let’s take a few examples. Let’s begin with the ARES rail system. I haven’t bothered to take a look at them intently as a result of they’re clearly nonsense and nobody has irritated me about them an excessive amount of, however I’m pretty acquainted with heavy freight rail and know that ARES has to play by the foundations similar to everybody else.

Metal wheels on metal rails signifies that heavy trains require lower than 2% grades in any other case they’ll’t go up hills. Which means you want a really lengthy set of rails to get very a lot peak. The size of the prepare signifies that it might probably’t get all of it up or down the hill, so you’re working with a portion of the slope.

Let’s load the rail vehicles as much as the utmost 130 metric tons for heavy freight rail every. Let’s use comparatively commonplace 18 meter vehicles. Let’s use 50 vehicles for a good size and mass prepare. That makes it 900 meters, nearly a kilometer lengthy.

At 2% grade, you’d want 10 kilometer of monitor to get 200 meters of head peak. However the trains size truly means you’d be solely getting about 9 kilometers of rise of the middle of gravity, so it’s truly 180 meters.

50 vehicles * 130 metric tons is 6,500 metric tons complete mass.

Mass * gravity * peak = 6,500,000 kg * 9.8 m/s^2 * 180 meters = 11,466,000,000 joules. That’s about 3.2 MWh.

The present Tesla Megapack is commonplace transport container dimension peak and width, 29 toes lengthy and shops 3.9 MWh. You may put them within the nook of parking heaps.

Yeah, an nearly kilometer lengthy prepare with ten kilometers of monitor has quite a bit much less vitality storage than a transport container stuffed with Tesla’s batteries.

There are funicular railroads that go up steeper pitches, however they’ve vastly much less mass as a result of the pressure on the cables will get so excessive that they snap. Shorter distances up steeper slopes contain related heights however vastly much less mass, so vitality storage drops by one or two orders of magnitude.

I don’t know what ARES is definitely claiming it’s doing as a result of it’s not price studying its web site, but it surely’s actually this stupidly dangerous.

That is bleedingly apparent to anybody who has spent any time doing mass and vitality calculations, one thing taught in Grade 7, which is why folks like me assume that issues like Vitality Vault will fail and disappear with out a hint, forgetting the gullibility of enterprise capitalists, the venality of SPAC pump and dumpers and the credulity of retail traders. Fools and their cash are quickly parted. Hopefully this may inoculate just a few folks.

Since we’re speaking about Vitality Vault, let me repeat my calculations from a couple of articles I wrote when the aforementioned gullibility, venality and credulity truly meant it had a market capitalization and getting a number of press.

Their first design, which they managed, remarkably, to make worse, had the crane within the heart and a bunch of concrete blocks that it will choose up and stack on prime of one another. The concrete blocks had been imagined to be 32 metric tons and the utmost stack dimension was 120 meters.

32,000 kilograms * 9.8 m/s^2 * 120 = about 37 million joules or about 10 kWh. That’s for one block going up the utmost distance.

However keep in mind, they had been stacking them. The typical block was solely going up half the gap, so each block was solely about 5 kWh of vitality. With 100 blocks, a notional and certain most quantity attainable in a round system like that, that’s solely half a megawatt hour (MWh) of electrical energy storage in the very best case situation.

The typical dwelling makes use of twice that a lot electrical energy yearly. It’s solely sufficient to cost 5 lengthy vary Teslas, and isn’t sufficient to cost a Tesla Semi.

So lengthy earlier than you get to the effectivity drawback — pretty poor — and the operational challenges like wind and cracked blocks, Vitality Vault is extra like Vitality Paper Cup.

Their second design solved for the wind drawback by making all the factor shorter and into an enormous, 25 story, 75 meter heavy metal framed constructing with completely large winches on prime, with barely smaller 27 ton blocks on rolling carts.

They’re stacking blocks on the underside so lose some peak from that. They’ll’t get all of the blocks to the highest of the constructing. 50 meters might be an affordable common per block.

27,000 kilograms * 9.8 m/s^2 * 50 = about 3.7 kWh per block.

Let’s suppose they managed to get 5 hundred of those large blocks working within the system. Unlikely, however let’s faux. That’s just one.85 MWh of storage, about half what’s in a single Tesla Megapack. In a 25 story excessive, thick metal framed constructing with mining grade winches on the roof.

They declare, in fact 40 MWh of storage, which might require lifting about 11,000 of their blocks to the highest of the constructing, the place there’s completely not sufficient room for them. There isn’t room for that many blocks in all the inside quantity of the constructing more than likely.

Hmmm, I haven’t accomplished that calculation. How a lot area would 10,800 blocks weighing 27 tons every of bolstered concrete take up? It’s 2.5 tons for a block a meter on a facet. Which means the 27 ton blocks could be three meters on a facet, which for the People studying alongside, slightly below 10 toes on a facet. You’d want a few meter between blocks at minimal for gear, carts and people large help metal girders, so let’s lengthen that out by half a meter in all instructions, making the area requirement 4 meters on a facet, or 13 toes.

Let’s make an enormous sq. of 10,800 blocks. How large is that? The dice root of 10,800 is round 22. That makes a sq. stack of those blocks with a little bit of room between them 88 meters excessive, 88 meters large and 88 meters lengthy. Does anybody discover something incorrect with this? Maybe that 88 meters is 13 extra meters than the Vitality Vault constructing is tall, and with zero room for the blocks to maneuver anyplace? Take away the spacing between them, and simply the blocks that may retailer the vitality that they’re claiming is sort of as massive as all the constructing. But somebody they’ll match all that into the highest couple of flooring? Magic area compression anybody?

As soon as once more, everyone seems to be pressured to play the identical sport as a result of that’s the legislation of thermodynamics and the sheriff is actuality. Vitality Vault’s storage claims are full and utter fabrications which fail absurdly easy physics exams. Let’s ask a query. When is these items taught in merely sufficient faculties. Reply? Grade 7.

That is actually a check a Grade 7 scholar may discover on a check, but folks put some huge cash into it.

Oh, and even with their absurd effectivity, lifespan and uptime claims, all that concrete and metal would have meant each MWh for 40 years would have had a carbon debt greater than burning pure gasoline.

There’s a purpose why as soon as the mud settled after the pump and dump SPAC, Vitality Vault employed a lithium ion battery website developer and began promoting nearly totally lithium ion batteries in transport containers as grid storage to shoppers. That some Chinese language individuals are apparently additionally gullible and credulous and have truly purchased and are establishing a few of these issues doesn’t imply that it’s a remotely helpful vitality storage system. That what funding cash was left over after the SPAC Wall Road folks took their large lower is generally going into the pockets of the 2 … eermmm … “inventors” of this nonsense goes with out saying. After attempting for 20 years to promote this sort of nonsense to credulous idiots, they lastly succeeded.

Okay, that’s sufficient kicking Vitality Vault — though actually, I don’t assume that they’ve been kicked practically sufficient, it’s simply that I’m bored with doing it proper now. Let’s discuss water towers.

By now, what the questions are. How tall is the middle of gravity of the mass? How a lot mass is there? Be at liberty to make use of that extremely tough scientific instrument, Google, that can assist you reply these questions.

Nah, I’ll simply do it. They vary from 40 to 50 meters. In case you’ve learn this far, your spidey sense shall be tingling already. That’s simply not that a lot. What about mass? On common, about 3,800 metric tons of water. Nicely, your spidey tense have to be ringing alarm bells proper now. However nonetheless, let’s do the maths. Let’s give it a break and assume a 50 meter water tower.

However that mass isn’t all 50 meters off the bottom. Water has a thousand kilograms per cubic meter, which is an instance of why the rational elements of the world use metric. Which means 3,800 cubic meters in a ball. How massive on a facet is that with the shell? About 16 or 17 meters in diameter. My guess earlier than calculating was 15 meters, which is 0.6 meters off the diameter if the ball of water was simply floating in area. Not a nasty guesstimate, and par for the course for anybody who spends any cheap period of time with this sort of factor. My being shut isn’t a function or one thing particular in different phrases, it’s simply an occupational hazard.

Okay, so the middle of gravity of the water is simply 37.5 meters off of the bottom. Large purple lights and sirens ought to be going off now.

3,800,000 kilograms * 9.8 m/s^2 * 37.5 = round 390 kWh. That’s possibly half a Tesla Semi battery again and a tenth of a Tesla Megapack.

However wait, there’s extra. Why do water towers exist? To offer water stress to communities in order that water truly comes out of faucets and fireplace hydrants when wanted in adequate volumes. What’s water stress? Vitality. Oh, wait. If we take the entire vitality out of the water because it comes out of the water tower, meaning there’s no vitality left for water stress. Dribbling showers and fireplace hoses aren’t any enjoyable in any respect.

What haven’t I ripped to shreds with Grade 7 physics but? Oh, yeah, mines and sand. I actually want folks weren’t severe about this, however they’re.

There are a few concepts, however the looniest one is sinking sand into an empty mine in massive buckets with regenerating winches, dumping the sand out on the backside and having massive autos push the sand down facet tunnels. To ‘retailer’ vitality, the autos working underground would scoop up the sand and dump it again into the buckets which might be raised to the floor.

Cease and take into consideration that for a minute. Utilizing loads of vitality underground to push sand round when the purpose is to retailer vitality. Why is that being accomplished? Nicely, sand isn’t a liquid, it’s only a bit liquidy among the time. Sand flows, however not like water. Pour water right into a mine and it’ll fill each nook and crevice as a result of it’s molecules of dihydrogen monoxide.

Water molecules are 0.275 nanometers. Sand grains common a millimeter. Nanometer, millimeter, what’s six orders of magnitude amongst buddies? Water molecules are about 4 million occasions smaller than sand, and so they aren’t all lumpy, coarse and spiky. They slip previous each other higher than the best high-thread depend Egyptian cotton or silk sheets it’s attainable so that you can think about.

So that is clearly a deeply silly concept, and but I’ve seen individuals who severely proposed it. The inefficiency is off the charts, and simply think about even autonomous electrical entrance finish loaders driving continuously by a mud cloud of smaller sand particles, getting of their gears.

The choice concept is to place loads of sand on a single elevator with large winches that simply goes up and down in an enormous, deep mine shaft. This one not less than has the potential to be viable. Let’s faux we are able to discover a kilometer deep mine shaft that’s deserted and hasn’t crammed with water as much as the 30 meters beneath floor degree mark. Oh, wait, we are able to’t discover one thing like that as a result of floor water? Ignore actuality for a minute.

Mine shafts have a diameter of 5 to twenty meters. Let’s faux we’ve an enormous 20 meter mine shaft that’s a kilometer deep and never stuffed with water. Okay, how massive a load of sand can we placed on an elevator in a 20 meter diameter shaft? Let’s assume we are able to put it in an enormous bin ten meters tall. In order that’s 20 meters in diameters and 10 meters tall of sand. That’s quite a bit. For People, that’s 66 toes throughout and 33 toes tall.

The quantity of a cylinder that dimension is 3,142 cubic meters. By the way in which, calculating that’s taught in eighth Grade. We’ve superior all the way in which to 13 12 months previous kids in primary faculties in our math and physics.

Sand has a density of about 1,600 kilograms per cubic meter. That’s about 5,000 tons of sand. Hmmm. Do we’ve winches that may raise 5,000 tons? Errr. No. That’s nearly precisely ten occasions greater than large winches for deepwater development. Okay, let’s pare that again. Perhaps a 1,000 tons of sand? Lower the depth to 2 meters as a substitute? Certain. Let’s try this math, as soon as once more, for this fictional, large, water free, deep mine shaft, certainly one of which could exist on the earth.

1,000,000 kilograms * 9.8 m/s^2 * 1000 meters = about 1,360 kWh. That’s 1.4 MWh.

That isn’t very spectacular. A kilometer deep shaft with an enormous elevator stuffed with two meters of sand labored by a few the most important winches ever constructed and it’s solely as a lot as a 3rd of a Tesla Megapack that’s 29 toes lengthy and eight.5 toes tall.

By the way in which, sand is filth low cost and the physics of winches signifies that it actually doesn’t matter if you happen to make the burden denser, for instance by utilizing lead. Doubling the burden nonetheless solely will get to 2.8 MWh, which is an terrible lot of engineering and development for a return nicely beneath one thing you’ll be able to order and have dropped within the nook of a parking zone.

Are we accomplished but? Not an opportunity. There are a bunch of people that assume that workplace constructing elevators are an untapped useful resource of vitality storage.

They assume that at night time, massive dollies of heavy stuff might be shoved into freight elevators within the basement, lifted as much as the seventy fifth flooring, and rolled into govt places of work and board rooms, then within the morning, dropped down once more to generate electrical energy.

I actually want folks weren’t saying this severely. I actually, actually do.

Okay, let’s make consider for a bit. How a lot weight can workplace constructing freight elevators raise? Large ones can handle 9 tons. What’s that sound? The sirens of spidey sense whooping. What’s that noise? The multicolored lights of spidey sense flashing. 9 tons? We’ve been speaking about 1000’s of tons. 9 of them? Actually?

Okay, however 75 tales. That’s quite a bit, proper? That’s like, actually excessive? Certain. Perhaps 225 meters. Okay, Grade 7 math time once more.

9,000 kilograms * 9.8 m/s^2 * 225 meters = about 5.5 kWh.

Some sweaty lackey goes to load 9 tons of paper or sand or stale birthday cake onto an enormous dolly, grunt it right into a freight elevator, then grunt it into board room, then reverse this course of the following day, and that is an vitality storage answer?

Let’s simply throw an enormous bucket of ice water onto this already absurd nonsense. Have you ever heard of counter weights? Elevators have these large weights that go up when elevators go down and vice versa to counteract all the burden of the elevator, cable, friction and the workplace staff. The purpose of that’s effectivity in transferring weight up and down. All of these elevators don’t have even 5.5 kWh to spare as a result of they’ve been designed to keep away from needing it.

The individuals who assume this concept is sweet have zero data of vitality, Grade 7 math or absolutely the fundamentals of elevators. Maybe they had been dwelling schooled within the prairies by Luddites or one thing. Decide your purpose why this fully absurd concept was truly gaining traction.

So let’s discuss closed loop, off-river, pumped hydro storage. Because the article headline says, it’s the one actual gravity storage possibility. Why? Nicely, as a result of it has billions of kilograms of mass a whole bunch of meters of distance between prime and backside. Geography creates the peak free of charge, simply requiring a ten meter diameter tunnel be dug by it, which admittedly is pricey and dangerous. And water’s tiny molecules don’t want any assist to arrange themselves. None of these sweaty confused workplace staff. None of these large front-end loaders pushing sand down tunnels. Simply pumps.

The mass and peak are each massive numbers. The mass particularly is a extremely massive quantity. And water is filth low cost. This isn’t filtered, bottled, purified, chlorinated water. It’s simply lake or river water. The water isn’t consumed. It goes up. It goes again down. It goes up once more. Advert nauseum. If water may get bored, it will. A few of it evaporates yearly, so the system must be topped up. Nothing burger.

Okay, let’s do some math. Let’s go to the Australia Nationwide College inexperienced subject GIS examine of potential paired reservoirs that weren’t on present water pathways, that had been near transmission, that weren’t on protected land and that had over 400 meters of distance between prime and backside reservoir. It discovered 100 occasions the potential capability for vitality storage as all the world requirement for vitality storage ultimately sport.

Just one% of the websites must work out with a view to present all of the vitality storage for a totally electrified world powered by renewables. And some blockers have already been eradicated. Near transmission and never on protected land, keep in mind? Somebody complained to me just lately that precisely certainly one of 616,000 websites recognized had 14,000 folks that may be displaced. So go to the following website already.

Math although. Let’s choose a 500 meter head peak website. Let’s choose a billion liters of water, a gigaliter weighing a billion kilograms, one million tons. Wait, what’s not taking place? Your spidey sense isn’t flashing lights and blaring alarms. These are massive numbers on each side.

1,000,000,000 kilograms * 9.8 m/s^2 * 500 = 1.4 GWh of grid storage.

Oh. GWh. Important grid storage. Okay, now we’re speaking!

Let’s take the three Clever Land Funding websites in Scotland, together with the Loch Ness Crimson John website that was just lately bought to Norway’s Statkraft. They’re designed to make use of lochs as their decrease reservoir and turkey’s nest reservoirs on overlooking hills as higher reservoirs. Plenty of water. Plenty of peak. Free water as a result of it’s simply sitting there within the lochs, ready to be pumped uphill in a really low environmental influence method.

2.5 GW of energy capability. 60 GWh of vitality capability.

Tesla Megapacks can ship about 2 MW of energy. That is like 1,250 of them. They’ll retailer about 3.9 MWh of vitality. That is like 15,000 of them.

Nicely, these have to be massive reservoirs, proper? No. A sq. kilometer up prime, a sq. kilometer on the backside. Ponds.

Pumped hydro is the one actual gravity storage answer as a result of it makes use of a mud low cost, excessive mass, simply pumped mass and makes use of present geographical function to create massive peak variations. Each different gravity storage answer is youngsters enjoying round in a sand field.

I’ll repeat this. Grade 7 math is all that’s required to determine this out. Entitled Hollywood belief fund youngsters Chad and Buffy, who get gold stars for attending class, are anticipated to have the ability to do that actually primary math in exams to move and get to Grade 8, maybe with examples of caviar on facet tables falling on the ground. Anybody who thinks that something apart from pumped hydro is remotely wise is a number of of some issues. They’re silly. They by no means made it by Grade Seven. They’re deeply lazy. They’re credulous. They’re gullible.

Don’t be that particular person. That is in regards to the lowest bar in vitality that it’s attainable to seek out. In case you can’t determine this out, you aren’t remotely competent to have discussions about any of the truly attention-grabbing stuff in vitality, like Ohm’s Regulation or substituting aluminum for copper in HVDC cables or why baseload vitality is an archaic time period left over from tiny grids enshrined in regulation gone its promote by date.