The Future Of Energy Storage Beyond Lithium Ion

May 24, 2020

Over the past decade, prices for solar panels and wind farms have hit record lows, generating hundreds of gigawatts of new renewable

energy

generation. However, as the saying goes, the wind doesn't always blow and the sun doesn't always shine. If, for example, it is a beautiful sunny day and we have plenty of electricity, we cannot use it. The question of how to consolidate renewable

energy

– that is, ensure that energy is always available regardless of the time of day or the weather – is one of the industry's biggest challenges. We need a good way to store energy for later.

And the main option right now is

lithium

-ion batteries. You see them in products like Tesla's home battery, the Powerwall, and utility-scale system, the Powerpack. But although the price of

lithium

ion is falling, experts say it will still be too expensive for most grid-scale applications. To get to the battery for the power grid, we must consider a further 10 to 20 times cost reduction. Right now, lithium-ion batteries simply cannot store more than four hours of energy at a price that would make sense. Additionally, they pose a fire hazard and their ability to hold a charge fades over time. To address this, there is a group of entrepreneurs experimenting with a variety of different solutions.

More Interesting Facts About,

the future of energy storage beyond lithium ion...

Now we're looking at flow batteries, which are liquid batteries, and we're looking at other forms of

storage

that are not chemical or battery-based

storage

. And each one has great potential. We looked at materials from the periodic table that were really going to be cost competitive from day one. The Primus Power Flow Battery is a workhorse. Thermal energy storage has a fairly unique opportunity to be extremely low cost. Our solution will last over 30 years without any degradation in that performance. It remains to be seen which technologies will prevail. But one thing is clear. For renewables to truly compete with fossil fuels, we must find a better way to store energy.

From 2000 to 2018, installed wind power grew from 17,000 megawatts to more than 563,000 megawatts. And solar energy grew from just 1,250 megawatts to 485,000 megawatts. And it doesn't stop there. Renewable energy is expected to grow an additional 50 percent over the next five years. Today we know that solar energy F.V. and wind are the least expensive way to generate electricity. In particular, the price of solar PV has plummeted much faster than all forecasts predicted, after China flooded the market with cheap panels in the late 2000s. All Wall Street analysts did not believe that solar energy would be self-sustaining without subsidies. Well, a few years later, even the most conservative analysts began to realize that solar energy was actually going to become economical in most of the world quite quickly.

And as solar energy has become cheaper, so have lithium-ion batteries, the technology that powers electric vehicles, our cell phones and laptops. And thanks to better manufacturing techniques and economies of scale, costs have fallen 85 percent since 2010. Now, wind or solar power plus battery storage is often cheaper than peaking plants, i.e. energy that only operate when demand is high. Tesla, for example, built the world's largest lithium-ion battery in Australia, combining it with a wind farm to supply electricity during peak hours. But this doesn't mean that lithium-ion is necessarily economical for other grid applications. We don't really see the cost structure getting to the point where it can serve those applications for tens to hundreds of hours.

Basically, the market is ripe for competition. Today dozens of chemistries are analyzed. There are hundreds of companies working on scaling up and manufacturing new battery technology. Lithium-ions have done remarkable things for technology, but let's get to something much better. One of the main alternatives being explored is a flow battery. Unlike lithium-ion batteries, flow batteries store liquid electrolyte in external tanks, meaning the energy from the electrolyte and the actual power generation source are decoupled. With lithium-ion technology, the electrolyte is stored within the battery itself. Electrolyte chemistry varies, but in general, these aqueous systems do not pose a fire risk and most do not face the same problems with loss of capacity.

Once they expand their manufacturing, these companies say they will have competitive prices with lithium-ion. Primus Power, based in Hayward, California, has been working in this space since 2009 and uses zinc bromide chemistry. It has so far raised more than $100 million in funding, including several government grants from agencies such as the Department of Energy and the California Energy Commission. The Primus modular EnergyPod provides 25 kilowatts of power, enough to power five to seven homes for five hours during peak power demand hours and 12 to 15 hours during off-peak hours. However, most systems use multiple EnergyPods to further increase capacity. The company says what sets it apart is its simplified system.

So instead of two tanks, which all other flow batteries have, Primus only has one. And we can separate the electrochemical species by taking advantage of the density differences between the zinc bromine and the bromine itself, and the more watery portion of that electrolyte. To date, Primus has shipped 25 of its battery systems to customers in the United States and Asia, including a San Diego military base, Microsoft and a Chinese wind turbine manufacturer. It expects to ship an additional 500 systems over the next two years. Future customers are independent power producers using utility-scale solar plus storage or larger commercial enterprises.

Also operating in this space is ESS Inc, an Oregon-based iron-flow battery manufacturer founded in 2011. Its systems are larger than Primus Power's. They are basically batteries in a shipping container and can provide anywhere from 100 kilowatts of power for four hours to 33 kilowatts for 12 hours, using an electrolyte made entirely of iron, salt and water. When we entered this market, we wanted to do so with technology that was very environmentally friendly. It was going to be very low cost. Not much volume was required on the production line to reduce costs. ESS is backed by some major players such as SoftBank Energy, the investment fund led by Bill Gates, Breakthrough Energy Ventures and the insurance company Munich Re.

Having an insurance policy is a big deal as it will make utility companies risk-averse publics are much more likely to associate with it. So far, ESS has six of its systems, called Energy Stores, operating in the field and plans to install 20 more this year. It is also in the process of developing its Energy Center, which is aimed at utility-scale applications in the 100+ megawatt range. That would be 1,000 times more energy than a single energy store. We plan to have a production capacity of 250 megawatt hours by the end of this year, which is probably a little more than 10 times the capacity we had last year.

And then eventually get to a gigawatt hour of production capacity in the next few years. Key clients so far include Pacto GD, a private Brazilian energy provider, and UC San Diego. But for all their potential, flow battery companies like Primus and ESS Inc are still not designed to store energy for days or weeks. Many of those flow battery technologies still suffer from the same fundamental material cost challenges that make them unable to achieve tens or hundreds of hours of energy storage capacity. Other projects that don't use lithium-ion, such as Ambri, a spinoff from MIT, face the same problem with longer-duration storage.

Form Energy, a battery company with undisclosed chemistry, is targeting the storage market for weeks or months, but commercialization is still far away. That's why other companies are taking completely different approaches. Currently, about 96 percent of the world's energy storage comes from one technology: pumped hydraulics. This system is quite simple. When there is excess power in the grid, it is used to pump water uphill to a high-altitude reservoir. Then, when there is demand for power, the water is released, driving a turbine as it flows into a reservoir below. But this requires a lot of land, disrupts the environment and can only work in very specific geographies.

Energy Vault, a gravity storage company founded in 2017, was inspired by the concept but believes it can offer more. That's why we wanted to look at solving the storage problem with something much greener, lower cost, much more scalable and something that could be brought to market very quickly. Instead of moving water, Energy Vault uses cranes and cables to move 35-ton bricks up and down, depending on energy needs, in an automated process with computer vision software. We have a tower crane system that uses excess solar or wind energy to power motors and generators that lift and stack bricks in a very specific sequence.

Then, when grid power is needed, that same system will lower the bricks and discharge the electricity. This system is sized for utility scale operation. The company says a standard installation could include 20 towers, providing a total of 350 megawatt hours of storage capacity, enough to power around 40,000 homes for 24 hours. Some of our customers are considering very large deployments of multiple systems to have that power on demand for weeks and months and as needed. The company recently received $110 million in funding from SoftBank Vision Fund and is building a testing facility in Italy as well as a plant for Indian company Tata Power.

But some say the size of the operation means it simply can't replace chemical batteries. It sounds very simple. However, the energy density in these systems is very low. And that's where we think chemical-based storage still has an advantage in terms of footprint. A gravity-based system cannot be installed in the city, but it would have to be installed outside, in remote areas. Then there is thermal storage. It is still an emerging technology in this space, but it has the potential to store energy for longer than flow batteries and takes up less space than gravity-based systems. Berkeley, California-based Antora Energy, founded in 2017, is taking on this challenge.

Basically, when there is excess electricity on the grid, it is used to heat Antora's cheap coal blocks, which are insulated inside a container. When necessary, that heat is converted back into electricity using a heat engine. Typically, this would be a steam or gas turbine. But Briggs says this technology is too expensive and has prevented thermal storage solutions from working in the past. SoAntora has developed a new type of heat engine called a thermophotovoltaic heat engine, or TPV for short, which is basically just a solar cell, but instead of capturing sunlight and converting it into electricity, this solar cell captures the light radiated by the medium. hot storage. and converts it into electricity.

So electricity goes in and out, and in the meantime it is stored in ultra-cheap raw materials as heat. Antora recently received funding from a joint venture between the Department of Energy and Shell, who are excited about the company's potential to provide storage for days or weeks. We believe that solves a need that is currently unmet and will continue to be unmet with lithium-ion batteries and will go some way to enabling the next wave of renewable energy integration into the grid. It's still early days for Antora and Energy Vault, however, and there are definitely other creative solutions in the mix.

For example, Toronto-based Hydrostor is converting excess electricity into compressed air. And Highview Power, based in the United Kingdom and the United States, is pursuing cryogenic storage. That is, using excess energy to cool the air to the point of liquefying it. These ideas may seem far away, but investment is pouring in and projects are being piloted around the world. While all of these companies compete to be the cheapest, safest and most durable, many also recognize that it is a market with many niches.and, therefore, with potential for multiple winners. In residential and commercial areas, you will have certain types of technology.

Much of it is likely battery powered. I think as you get to the utility and grid scale, you'll see some batteries, you'll see other types of compressed air and liquid air solutions, and then you'll see some of the Gravity Solutions that could be scaled up. Overall, the energy storage market is projected to attract $620 million in investments by 2040. But, as always, it will be difficult to bring even the most promising ideas to market. It doesn't matter if the raw materials were very cheap, the initial cost of a first system is essentially astronomical. Of course, government policies and incentives could also play an important role.

There is a tax credit for the production of wind energy. There is a tax credit for investing in solar energy. We in the battery community would like to see an ITC for batteries in the same way it exists for solar. Implementing a storage mandate, as California has done, is another policy that many advocate. When we reach about 20 percent of our peak demand available in storage, we will be able to run an exclusively renewable system, because the combination of solar, wind, geothermal and biomass, all backed with storage, will be enough to carry us through. even some of these potentially long pauses.

With the right combination of incentives and ingenuity, we will hopefully be headed toward a