At remote cell tower sites in India and Africa, getting electricity to keep the telecommunications system running is a costly and difficult engineering challenge. Some of the systems have weak connections to an unreliable and intermittent power grid, with diesel back-up. Other sites are off-grid, with only diesel engines to keep them functioning. Fuel is expensive, and shipping it is neither cheap nor easy. Theft of fuel is also a frequent occurrence. It’s a tough place to have to run a cell tower. It’s also a bad place to have to use most kinds of batteries. Temperatures can average close to 100 degrees Fahrenheit, and max out at 125.
Which makes it a perfect test bed for Imergy to install its Vanadium Energy Redox Storage Platform. In India, the company already has 70 systems functioning, some of them for up to two and a half years. With diesel back-up generation being so expensive, you have to take advantage of the power grid when it is functioning and grab the electrons when you can get them. In such an environment, you have to charge fast, and you have to run long. Imergy CEO Bill Watkins comments that the Indian environment has provided a very good use case for his vanadium electrolyte storage technology.
When the grid is there, you charge the battery. And when it disappears the battery takes over and discharges for ten, twelve hours, or longer. We can charge 3 times faster than it takes to discharge. There’s really no practical limit to how fast you can charge. We are a liquid battery and heat comes out in the liquid, so we can run at full power without cooling and with no degradation and lifetime impact.
Of course, the ultimate goal of this company is to move into markets well beyond India and Africa. Those countries just happened to be ideal places where avoided costs are high, the value provided is significant, and the systems can be put through their paces. Longer term, Imergy is focused on entering the broader energy solutions market.
The electricity storage game has started to heat up recently, and the storage space is being populated by a very interesting mix of companies and competing technologies. It’s about to get an additional potential boost from the U.S. Department of Energy as well, with the DOE making part of its remaining $1.5 billion in loan guarantees available for storage. The focus will be less on utility-scale projects and more on smaller scale projects.
Looking at the best-known battery technologies, one has to start with the lithium crowd. Lithium is popular because of its energy density relative to weight. As Tesla and other EV makers have demonstrated, one can pack a lot of kilowatt-hours into a relatively small space. That’s why it’s good for electric cars. But it’s still pretty costly for other applications on the utility grid.
There are the companies like Ambri (formerly Liquid Metals), whose founder – MIT Professor Donald Sadoway – is fond of saying if you want storage to be dirt cheap then you have to make it out of dirt. Aquion has a similar focus, making a saltwater electrolyte battery ‘using abundant, nontoxic materials.’
And then you have Imergy, which has its own unique vanadium-based electrolyte storage technology which its president, Bill Watkins, characterizes as “a game changer.”
A former CEO of Seagate and Bridgelux, Watkins was attracted to Imergy by the technology.
I came to this company because they made a breakthrough in chemistry which is massive and a fundamental game changer. The company had made a groundbreaking discovery around electrolytes. We have a chemistry that will last forever and will never deplete. It never wears out. It always has a residual value as vanadium. It operates at 50 centigrade without degradation.
Another advantage enjoyed by Imergy is that its vanadium is relatively cheap. The company can take the metal from fly ash or as a byproduct in the slag from steelmaking, reprocess it for about a half the price of buying vanadium on the market, and utilize it at 98.5% purity.
Tim Hennessy, president of the company, noted that flow batteries were originally developed as large industrial-type devices to handle utility-scale activity. Hennessy, who got into the battery business after working at a Bechtel/Siemens company, recognized that the key issue to be solved was cost.
The challenge was always cost. In initial vanadium batteries there were limits as to what you could achieve. It didn’t give you the cost capabilities…the key thing I saw was the ability of our battery to use lower quality and higher density vanadium in its electrolyte. That gave us the ability to drive the price down to commercial and general adoption.
So the company focused on creating a battery that could utilize low-cost vanadium from industrial waste streams. There are several advantages to vanadium. It lasts indefinitely, and it’s a hard asset that a financial institution can feel comfortable with as bankable collateral. Hennessy comments that the reason the electrolyte never wears out is that there is no cross contamination of chemicals or any adverse side reaction, a characteristic unique to vanadium batteries. As a consequence,
Whatever you put in on the vanadium side you will recover. It has residual value and it’s bankable. We have an asset that does not disappear. It’s pure vanadium.
Watkins indicates that once the basic chemistry was solved, the challenge was to scale it and deploy in the real world,
The cell deck is 5-10 kW. The ability of the technology is to scale from there by making it modular and increasing the size of the electrolyte tanks. They can be built into 40 foot container - 250 kW - building blocks.
Watkins notes that Imergy’s current focus is on projects under 10 MW in size. Rather than focusing on grid-scale projects, the company is looking at high value applications behind the meter.
Most battery companies are focused on 250 kW to megawatt solutions. We start at the low end and move to the high end. Megawatt storage projects are lumpy up and down. We are focusing on telecoms and micro-grids where you can deploy routinely and fast. We will focus on basic volume production. Then we will focus on 250 kW modules and up.
In September, the company plans to deliver a 20 foot container with 120 kWh and a 30 kW power rating. That will shortly be followed by a 250 kW kit in a 40 foot container. Starting with back-up of telecommunications in India, one next logical step is to include PV where it makes sense, and potentially move into micro-grids that could be islanded (disconnected from the grid) or grid-tied.
In addition to India, the plan is to move where markets offer the best opportunities. In the U.S., parts of New York, Texas, and Hawaii (the latter with some of the country’s highest electricity costs) may make sense.
We are also looking at China, but that would be a second area of focus. The final area is utility deployment, which a is longer time play where you need scale. It's utility controlled and everybody is chasing it, while laws and regulations are evolving.
In the pantheon of energy resources, storage is rather unique. There are many different storage technologies (not just batteries: you can use pumped water, elevated rail cars, and compressed air, to name just a few) that can store and deliver capacity and energy. And just as there are many forms of storage, there are many different potential applications in the power grid (as well as transportation).
Different technologies run the spectrum from providing capacity (also know as 'power' - a relatively high level of KW, often with short lead times) to more of a focus on energy (longer run times with less of a focus on how much you can deliver at a a specific point in time). Each of the various companies entering the space must define its own niche and business model, based on the chemistry and capabilities of the technology it brings to the game.
While Imergy can play in the valuable fast reacting frequency regulation and synchronous reserve markets (required to balance the power grid within short timeframes), it’s the longer duration applications where their technology adds the most value.
Our battery can provide all of those services – it is extremely fast responding but the economics (for quick response) are better with some other technologies. If you only need short response, you won’t get your best bang for the buck with flow batteries.
One way to maximize the value of storage is to find multiple applications and markets for the same technology, so that you can harvest the same capacity in different ways. Watkins notes that Imergy has an eye out for such markets,
If you do something combining both power and energy you can catch both value streams. You can increase the size of a flow battery by simply adding more electrolytes – you get economies of scale on the energy component.
The other value inherent in Imergy’s vanadium-electrolyte technology is that one doesn’t need to layer much software on top. Watkins indicates the level of intelligence required is minimal and there’s not a lot you need to do to keep it running,
You have to make sure you don’t overcharge it. You have to make sure the pumps are running – the ones that move the liquids around. When it gets charged, we measure the state of charge and stop charging. It runs low pressure and low temperature and it’s an industrial type product...We manage how fast you want to charge it and how fast you want to ramp the charge and the discharge.
Watkins also notes that the vanadium storage systems provide flexibility for pulling power from - or delivering power back to - the grid. This is a valuable trait, since the balancing of the grid involves both sides of the equation, especially when intermittent renewable resources are involved,
We can stay at half charge. Flow batteries are good for wind, where you want to stay at midpoint.
What the vanadium system cannot do is be reduced in size, but that’s not what Imergy is focused on,
We are never going to be small. You have about a third the energy density of a lithium battery. We will never be in an EV, but you never have to worry about fires.
As the penetration of intermittent renewables such as wind and solar grow, the need for resources to balance their contributions will increase as well. The storage market is expected to become a multi-billion dollar market within 4 years. Research firm IHS predicts a dramatically steep growth curve - from about 340 megawatts (MW) of global installed storage in the last two years to annual figures approaching 6,000 MW in 2017, and increasing to as much as 40,000 WW by 2022. A number of storage companies have their eyes on the prize, a prize so large that there is ample room for multiple winners and technologies to emerge. Imergy, with its unique vanadium electrolyte technology, intends to be one of them.
