A California startup is repurposing trains and rail cars to help renewable energy utilities compete with fossil fuels.
August 21, 2017
6:45 AM EDT
What goes up must come down. This principle applies to most things in our current gravitational setup — college tuition being a conspicuous exception — and it could provide a significant boost to green energy initiatives, too.
A California-based company called Advanced Rail Energy Storage (ARES) is using the power of gravity to help renewable energy utilities compete with coal and gas. The idea is to help solve the perennial problem of energy storage. Because wind and solar installations can’t always generate energy on demand — sometimes it’s cloudy and the air is still — green utilities need a reliable method of storing surplus energy.
There are several ways to do this using high-tech industrial batteries, flywheels, or hydroelectric facilities, but these approaches tend to be expensive and complicated.
ARES’s solution? Run some old trains up and down a hill.
The company harnesses the power of potential and kinetic energy to help utilities add and subtract to the energy grid as needed. When the wind or solar farm is producing excess energy, that power is shuttled over to the adjacent ARES facility. The surplus energy is used to power repurposed electric locomotives, which in turn haul enormously heavy railroad cars to the top of a hill.
When less energy is being produced but more is needed for the grid, the railroad cars roll back down, turning potential energy back into kinetic energy by powering onboard generators with the force of their descent. The technique is similar to the regenerative braking system that is used in electric and hybrid vehicles, which routes deceleration energy to the vehicle’s battery.
RELATED: Next-Gen Geothermal Could Unlock Vast Energy Supplies Just Below Earth’s Surface
The system is also similar to existing hydroelectric (“pumped hydro”) solutions that essentially do the same things with water — pumping water uphill and capturing downhill flow. A benefit of the rail energy storage solution is that it doesn’t need to be near a large source of water. That’s good for wind and solar installations, which are often located in remote areas.
It’s cheaper, too. Ares contends that its rail energy solution costs about half as much as competing energy storage solutions, and has less of an environmental impact.
ARES
“We use no water, burn no fossil fuel, produce no emissions, and use no hazardous or environmentally troubling materials like lithium,” ARES CEO James Kelly told Seeker. “We are excited to be a green storage solution that can enable higher penetration of intermittent renewable resources — like wind and solar — in the US and around the world.”
Pushing rocks up a hill might seem like a curiously low-tech approach to energy storage, but Kelly said that this very simplicity is what gives rail energy storage an edge. Building a railroad loop is a lot simpler than maintaining a giant battery farm, and the ARES system can easily use repurposed locomotives and freight cars. An ARES site can be quickly and cleanly decommissioned and restored in months rather than years or decades, Kelly said.
None of this matters unless the system is efficient. Rail energy storage has about an 80 percent efficiency rate, meaning that the descending railroad cars can output 80 percent of the energy that was initially used to get them up that hill.
That’s better than pumped-storage hydroelectricity, Kelly noted, which typically runs in the 60 percent range. Batteries can return a higher efficiency, but their capacity degrades over time.
“The real question is how much you get out when you need the energy,” Kelly said. “If you discharge your storage batteries tomorrow, you will probably get 90 units out. If you discharge in six months, you may get 40 or 50 units. ARES units have essentially infinite cycles with no degradation.”
“What we’ve done with ARES is harness the inexhaustible, entirely reliable power of gravity,” he added.
HT/Rod Everson
Discover more from Watts Up With That?
Subscribe to get the latest posts sent to your email.
I had this idea years ago, sort of. And I thought when I saw them build those bird roasting water heating towers in the desert, that they would surly implement the idea.
But my idea was to build a tower with a elevator type setup, which during the good Sun hours, say 6 hours, the extra 18 hrs worth of generated power would go toward raising whatever sized/calculated weight to gear ratio was needed to generate a couple three days worth of no Sun power for a system. The solar panel Kwh would be sized to at least be able to generate 24 hours worth of power in that 6 hours of good Sun time. While the weight would be raised (sized and geared) to a height which would fill the other 18 hours of non generation time. Plus a few extra hours to ideally build up a couple three days worth of backup over time.
What about giant undersea balloons being inflated by Solar and wave energy over the Marianas trench, floating massive bags of rocks to the surface, then getting energy from the rapidly deflating bags at the surface and GPE from the rocks sinking back down the 7 miles to the bottom? Or something similar?
Hum, perhaps a bit problematic to inflate balloons under an ocean of pressure, bit that I want to burst bubbles.
However if we can get middle income folk to pay for it, and give some of that income to rich Tesla owners, we can probably get funding in Kalifornia.
The boys from the East Side have had an idea which could make us more money than vice or gambling.
It comprises an office with cheap researchers looking for Green government grants being offered. These are passed to a group of accountants/lawyers for evaluation. Those deemed profitable are passed to a small team of failed engineers whose job it is to put forward vaguely believable proposals for machinery that can attract funding. The lawyers then put a grant application in.
We can get start-up costs funded by Soros, and we will need sign-off from Greenpeace – for which I propose to offer them 10% of the take….
Dodgy Geezer, that is brilliant. I’m in!
I’ve a better idea for windmills backup system: A pendulum clock system.
When rid or wind is high the extra power will lift a weight and when the rid require and wind is low the weight will supply the power.
I’ve a better idea for windmills: A pendulum clock system!
I think, I can… I think, I can …
A bit slow here at WUWT.
Euan Mearns over at his blog site Energy Matters ran through and analysed the claims and the figures on this ARES rail line energy storage project in April 2016.
He also has a graphic comparing this and other energy storage systems in the same blog article.
It might even work if the good citizens of the USA wish to spend a good high percentage of their GDP setting such an energy storage system up.
http://euanmearns.com/is-ares-the-solution-to-the-energy-storage-problem/
Just one of an excellent series of posts at that site on various forms of energy storage, and also on the requirements for storage to support various energy sources. Few seem to realise the timescales over which storage is required to make intermittent energy sources viable without other backup, and just how large those energy stores need to be.
http://euanmearns.com/tag/energy-storage/
Pushing s**t uphill.
Off the truck he darted against the rocks he crushed
Upside down the engine turned and Georgie’s breast did smash
His head laid against the firebox door the flames were rolling high
I’m proud I was born for an engineer on C&O road to die
The doctor said to Georgie my darling boy be still
Your life may yet be saved if it is God’s blessed will
Oh no cried George that will not do I’d rather die so free
I want to die for the engine I love one hundred and forty three
You don’t even have to stretch it you could just spin the rubber band up like we used to do on those old balsa wood toy plains we had.
For the solar just charge a big battery and then use it to shine a light on the panels at night. Or how about putting a giant mirror on the moon and shine it at the panels at night.
The storage idea is not totally ridiculous, its the generating idea that is messed up.
Interesting.
The challenge of transmitting the power generated from the roll back comes to mind.
But I guess tgat can be dealt with at the same time a mountain tall enough for the gravity train to roll down for days at a time is constructed.
Except…
Pumped storage works because the electricity generator used to do the pumping off-peak is dispatchable, so the storage can be recharged as required and planned.
Wind power (and solar) is not dispatchable so once the train has run down the hill, there is no guarantee that the wind/sun generation will be available or sufficient to move it back up the hill when needed.
The train therefore is exposed to exactly the same problem it is suposed to resolve.
How great is this? The windmills can kill everything that flies and the rail system will kill anything that walks. What’s really needed is a renewable idea that will kill everything underground and in the ocean. That will achieve the dream of the enviromental folks.
This is an old.old idea that never got off the ground. I first heard of it over 5 years ago. This article is totally misleading in presenting this as anything new. The only viable large storage facilities has always been pumped storage. But pumped storage is only viable when it is an alternative to dumping unneeded power off the grid. It is not particularly efficient – I believe that you lose 25 to 30% of the power being stored via transmission losses, evaporation and the inefficiencies of pumps and generators. The reduction in cost of natural gas more or less eliminates any advantages of pumped storage. California, our own renewable crash test dummy has been constructing pumped storage facilities in the mountains, at tremendous cost (roughly the same as a nuclear plant, as I recall – about $4 to $5 billion).
All of this is the same old silly idea that one can make wind/solar generated power controllable.
Someone needs to inform these people that a stored power unit canot generate power – it can only store it, and it must be replenished after it is depeleted, which isn’t long. As I recall, at full capacity, those very expensive pumped storage facilities can only produce power for about 10 hours. The wind can die down for long periods of time, as can solar energy (except usually in a desert).
When are the technologically ignorant/inept Californians ever going to understand that we are on the threshold of a new form of nuclear energy (molten salt Uranium/Thorium reactors) which will transform the world. California is instead interested in this 19th century technology, a silly rail scheme using choo-choo trains and a big hill.
China and India’s govt are not energy-ignorant like the braindead California govt and are rushing to develop these reactors as we speak. I can pretty much guarantee that any Chinese or Indian energy scientists who read this article will be much amused and become overly confident that they have nothing to fear from American technology. They are probably laughing out loud about now.
Only in a country populated with large numbers of desperate global warming fear mongers could this article be published and taken seriously.
And yet, those who question this guff are the science deniers. Wow.
I mean look at all the money earned by those who built it! It’d be wasted and those poor folks would be unemployed!
All those bribes lost like tears in rain.
For crying out loud… How ridiculous. Just build a super critical coal fired power station and generate base load power at low cost.
Strikes me that you will use a lot of land for these trains – in much the same way as you need a lot of land for solar and wind generation. The critical energy factor is height and weight, but the generation factor here is friction – the train wheels on the track. This there is limit to how steep the rail line can be before slippage becomes a significant loss. Someone mentioned gradients of 2% up-thread so for a 1000 m height, you need a 200 km track. That is a lot of land.
One of the factors which makes pumped storage so popular is the speed of despatch – i.e. how quickly can you start generating power when you need it. Do these trains need to get to a certain speed before they can generate power? When they have to be brought up to phase to feed into the power supply, then the speed of the turbine is critical. For a 1000 ton train there is a lot of mass to get moving before any power is being generated.
I see Reed Corey has already done these calculations (August 23 10.23pm). And I made an arithmetic error! Need more coffee!
Huh. Sisyphus lives.
Daddy, We’re cold.
Sorry kids.
The train has come to the bottom.
Anthony, thanks for the H/T. It’s nice to know that Tips and Notes serves a useful function.
While the comments were more heavily weighted toward snark than usual, many were interesting, as was reading more on the system at their website.
The comment that I suspect will turn out to be most on target was Bob Boder’s: “The storage idea is not totally ridiculous, it’s the generating idea that is messed up.”
You have to bear the cost of operating and maintaining a railway just to store a portion of the energy normally used for fuel. There is a reason why railways close underused lines. They are very expensive to maintain.
All of this depends on the train being at the top of the track when you need energy and at the bottom when you need to store. Intermittent energy sources and demand don’t align their timing with the needs of your storage system. Batteries have the same problem.
Yeah, but if it spun backwards, wouldn’t it just suck the power out of the lines? (▰˘◡˘▰)
I know the perfect place for this. The Medicine Bow mountains in Wyoming. There is a flat plateau about 10 miles across at about 10,500 feet a s l and a drop of about 2,000 feet over five to fiften miles almost all around.
We turn the plateau into the worlds’ largest marshalling yard and build a couple of thousand railways down the sides. It would probably not cost much more than a dozen transcontinental railways.
SA reported on this over 3 years ago.
https://www.scientificamerican.com/article/energy-storage-hits-the-rails-out-west/
The cost of constructing or repurposing steeply inclined rail beds and tracks is extremely non-trivial. In order to have enough rolling mass to store any significant amount of energy, I’ll wager the construction costs would be in the billions of $ for anything over 100 MW or so of capacity. This is not counting all of the peripheral equipment like transformers for step-down and step-up, transmission lines, etc. Then you get into land use rights acquisition and environmental mitigation and permitting ….
You have got the conductors for the transmission lines already, just need to work out how to stop the bogies shorting them out.
For anyone considering vertical towers, bear in mind you need a 3000ft tower that stores 3 million tons at the top to have a similar capacity to the unit described in the promotional material. Or you could have 10 x 300ft towers, with 3 million tonnes at the top of each.
Actually, it makes more sense to increase the mass and reduce the height. How about a 30ft drop and a mass of 300 million tons? Getting the energy back could be a problem.
A “3000ft tower that stores 3 million tons at the top” would have a capacity of 6.7 GW-hr.
It would have better efficiency, less maintenance, and there is no reason you couldn’t have a whole city of them with more realistic height and mass.
I am not sure that building a tower nearly 200m taller than the current tallest building in the world, then sliding 3 million tons up and down it, would have less maintenance than a railway up a hill.
The more realistic height and mass was my final point. A small height and a huge mass could store the energy quite well, but I do not know how to get the energy back. The movement would be very small and massive amplification or gearing would be needed. I don’t see how we could do this without huge losses.
It’s a step in the right direction (thinking wise). One more step and we could cut out the middle man and apply gravity directly to the molecules in the atmosphere. There is a hell of a lot of P.E. up at 100km, and quite a lot of mass in the atmosphere to play with. I think an experiment might be in order when Doug have finished playing with my model railway.