Environment

ARES system to put energy storage on the right track

ARES system to put energy stor...
The ARES system uses electric locomotives as a form of energy storage
The ARES system uses electric locomotives as a form of energy storage
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The ARES system puts vehicles in a queue on a single track
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The ARES system puts vehicles in a queue on a single track
The ARES system uses electric locomotives as a form of energy storage
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The ARES system uses electric locomotives as a form of energy storage
The ARES pilot vehicle axles are each driven by a high efficiency motor/generator via a low friction carbon fiber belt
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The ARES pilot vehicle axles are each driven by a high efficiency motor/generator via a low friction carbon fiber belt
The ARES Tehachapi pilot track with the orange conductor rail on the left
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The ARES Tehachapi pilot track with the orange conductor rail on the left
ARES Co-Founder William Peitzke standing next to pilot project vehicle
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ARES Co-Founder William Peitzke standing next to pilot project vehicle
The electric bays of the ARES pilot vehicle
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The electric bays of the ARES pilot vehicle
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We’ve recently looked at ocean-based energy storage system concepts from MIT and Subhydro AS that are designed to overcome the intermittency problems of renewable energy sources like wind and solar by pumping water out of large tanks and using gravity to let it back in and generate electricity when needed. Santa Barbara, California-based company Advanced Rail Energy Storage (ARES) has come up with a land-based alternative that would provide grid scale energy storage using electric locomotives.

ARES’ technology uses heavy rail cars that are pushed to the top of a grade using excess power from renewable energy plants or when electricity demand is low. Then, when the wind drops, the sun stops shining, or electricity demand rises, the rail cars are released back down the hill, generating electricity through regenerative braking.

Because the system doesn’t rely on the use of water like the aforementioned ocean-based systems, the company says the technology is suitable for a wider variety of areas with minimal environmental impact. The company says the system can also respond to increases or decreases in demand in a matter of seconds, boasts a charge/discharge efficiency of 86 percent, and can deliver constant power for periods of up to eight hours.

ARES’ Director of Technology Development, William Peitzke told us to think of the system as basically a “grid-scale flywheel or battery, but one which is able to lock into direct synchronization with the grid providing heavy inertia for added grid stability.”

The company says its system is scalable and can be configured to provide grid-frequency regulation systems from 10 to 200 MW power and grid scale energy storage systems from 200 MW power with 1 GWh of energy storage, up to regional energy storage hubs of 2 GW power and 32 GWh of energy storage. ARES adds that its system also boasts a higher energy-to-power ratio than flywheels, a lower life-cycle cost than batteries and a faster ramp-up rate than pumped-storage.

The ARES system puts vehicles in a queue on a single track
The ARES system puts vehicles in a queue on a single track

With multiple vehicles position on the same track, the vehicles move independently and can be positioned mid-elevation in a queue. As one vehicle comes out of the queue at the end, another enters the queue to maintain a constant power into or out of the grid.

Power is transferred to and from the vehicles by way of a conductor rail, while vehicle speed and location information gathered from small leading wheels on the vehicles is transmitted to a control station that coordinates the vehicles based on current energy requirements and prevents the vehicles from crashing into each other. In the event of a power disruption, air brakes on the vehicles activate automatically.

ARES recently held an open day at its R & D facility located in Tehachapi, California. Built as a proof of concept for its patented Regulation Energy Management (REM) system, the pilot plant is designed to even out intermittent power supply from a neighboring wind farm. This facility features a pilot vehicle that weighs 12,500 lb (5,670 kg) and runs on a 15-inch (381 mm) gauge track that is 880 ft (268 m) in length, making it 3.75:1 scale when measured against a standard 4 ft 8.5 inch (1,435 mm) gauge track.

The company is currently in the middle of the permit process to construct a full-scale commercial 50 MW REM system in Pahrump, Nevada for the Valley Electric Association and the California Independent System Operator (CA-ISO). This system will extend the length of the track to 5 miles (8 km) and up the weight of the individual vehicles to 300 tons (272 tonnes). The single track will be on an eight percent grade and have 32 vehicles operating on it, each able to absorb or provide around 1.5 MW of power.

ARES CEO Jim Kelly adds that the system can "be deployed at around half the cost of other available storage technologies. Just as important, ARES produces no emissions, burns no fuel, requires no water, does not use environmentally troublesome materials and sits very lightly on the land.”

The following video illustrates how ARES’ REM system coordinates multiple vehicles on a single track to deal with intermittent power supply.

Source: ARES

Ancillary Services Facility

23 comments
Jonathan Lodge
I designed a similar system (albeit a simpler, less refined one) as part of my Engineering degree a couple of years ago, I'm so pleased to see that someone else has come up with this idea and that it is being realised. Hopefully full scale systems will be rolled out and address the intermittency problems of renewable energy sources.
Craig Jennings
Rail is great for lessening friction, but that can be a problem when accelerating or breaking. Wonder if they'll end up with another track for that purpose and regular track to roll the carriages on.
The Skud
Seems like a good idea, however, once the last car rolls down to the bottom, that's it! I would like to see a 'looped' or similar system where some of the power is diverted to pushing a few cars back up again - simultaneously - while using the downward-moving cars to generate power. i.e. 20 cars available for generation, move 5 cars back to the top slowly or gently while the last 15 generate. Tagging on the top end makes at least 25 cars plus possibly another 5 added to the total movement overall for extra generating.. Not 'perpetual motion' but every little helps!
Fusionmkx
You could put solar panels on the track vehicles as well or the tracked vehicles could use a hybrid battery/flywheel system as well to maximize the surface area exposed to the sun.
Slowburn
It looks good if not great. It needs a large number of motor/generators but it is certainly something that could be built with off the shelf components today. It might be worthwhile to put sails on the cars.
Bob Stuart
How could anyone imagine this as cheaper than pumped hydropower storage? One way to do it does involve a railway, but the cars get used over and over, not left at the top of the hill.
ElTerencio
I have thought about the use of trains for energy generation, but more in the line of capturing the energy that is wasted during the braking process. If there was a way to use a passing train that was decelerating to help lift these other cars or to generate energy (mechanical or electrical). This energy may also be used to help with getting the train rolling again after stopping. After all locomotives are run with electric motors that huge diesel generators power.
Max Kennedy
a simple gravity storage system. Would work well.
Barry Dennis
Maybe this works fOr emergency power purposes, but I fail to see the everyday utility, since we ARE STILL DEALING WITH REAL PHYSICAL LAW effects LIKE FRICTION, POWER CURVES, AND REDUCED CAPACITY AT EVERY TURN.
jerryd
As someone doing RE, EV's, etc this looks real good except train rails won't work on such slopes needed, not enough traction. But a rack on the ground solves that as with other mountain trains with the same problem. You could store weight cars at the top to reduce loco needs. With say 3 roads, it doesn't have to be tracks, such a unit could be very useful leveling demand, supply loads. If you happen to have a at least small mountain handy that is. You'll need over 1,000' rise likely to be good but many places are like that on both coasts. Sadly not here in Fla.