One major drawback with renewable energy is its volatile output. Because renewable energy relies on the right climatic conditions to produce maximum power, unfortunately time-dependent demand requirements cannot always be met. This has been a major stumbling block in terms of providing base load capacity. Hence, we are still stuck using coal-fired power stations and even OCGT (Open Cycle Gas Turbine) technology.
Enter energy storage, another one of those trendy catchphrases doing the rounds of late. Energy storage has always been behind the curve compared to actual renewable energy technology, but this is about to change. With massive investment put into energy storage R&D, the rewards of those seeds will come to fruition sooner than later. Think of the possibilities with advanced energy storage. We will be able to store our produced renewable energy on a large scale, maintaining capacity until it's required for expenditure.
Energy storage technology can also be used in demand response applications and, when considering electric cars, renewable energy storage is a complete game changer. We live in exciting innovative times, where energy storage will be a major disruptor for the utility market, traditional combustion engine cars, oil companies, and beyond.
These are ten companies affecting the landscape when it comes to renewable energy storage.
Aquion Energy is a U.S.-based energy storage manufacturing company, they have come up with a unique energy storage solution that is based on 200-year-old technology. Namely, saltwater batteries with much-needed modern-day improvements. The battery is manufactured from abundant, environmentally safe materials using low-cost manufacturing techniques. The battery technology is scalable, from a residential solution all the way up to utility grade energy storage requirements.
They are also non-toxic, chemically stable and non-flammable, unlike lithium-ion batteries. These unique batteries require nearly zero maintenance and extremely reliable. They can be discharged to zero or even left at partial charge without irreversible capacity loss, much like lead acid batteries.
High View Power is a UK-based company that develops energy storage solutions for the utility market. Their systems are sized anywhere from 5MW to 200MW, a range befitting of its industrial purposing. Meanwhile, they provide up to 1.2GWh’s of electricity. What makes these utility scale batteries special is their use of liquid air to store energy. Liquid Air Energy Storage, or LAES, can be constructed with off-the-shelf components and has a 30-year lifespan. It’s also cost effective and based on existing technology principles.
So how does it work? In simple terms, it uses a massive charger to power an industrial liquifier which produces the liquid air, which is then stored in low pressure tanks. When power is required, the liquified air is drawn from the tanks and pumped at high pressure, reheated and expanded. The heated high-pressure gas is used to drive expansion turbine generators to produce electricity. No fuel is burnt in the process, resulting in clean dry air exhaust.
Tesla CEO Elon Musk is changing the way the world thinks about batteries, bringing to life a reality where they can be used in the home and utility environments. The Tesla Powerwall is based on Lithium-ion battery technology, and has several energy storage properties which differentiate it from the older deep cycle lead-acid based battery technology. Lithium-ion batteries are far superior in that they have a much higher energy storage capacity, can be charged much faster and can be discharged down to 80% without damaging the battery. They also have a much longer lifespan than lead acid batteries.
The Tesla Powerwall 2 has a usable capacity of 13.5 kWh of electricity. Tesla also manufactures a commercial sized version for larger applications called the Powerpack, which has a usable capacity of 210 kWh. Both the Powerwall and Powerpack can be connected and scaled to increase energy storage capacity.
Ambri was born out of an MIT laboratory, the same setting where the first liquid metal battery was developed. The liquid battery is distinct from other types of batteries in that it's the only battery where all three active components are in liquid form when the battery operates. The system operates at elevated temperatures maintained by self-heating during charging and discharging.
The result is a low-cost, long-lifespan storage system. The materials are also found in abundance, which a major advantage when it comes sourcing material and manufacturing costs. The battery also has a long lifespan, is reliable and can be easily scaled up to utility sized solutions.
EnerVault is another homegrown energy storage innovator based in California. EnerVault is one of a few companies which manufactures redox flow batteries. The company designs and manufactures redox flow batteries for micro-grid, industrial, commercial and utility scale operations. NASA originally pioneered redox flow batteries in the 1970’s.
These batteries employ vanadium ions in different oxidation states to store chemical potential energy. The lifespan of a redox flow battery is not affected by depth discharge or number of cycles, as other forms of batteries are. They are also designed to operate at much higher current and power densities than conventional batteries, also making it unique.
Redflow is an Australian-based energy storage company that manufactures zinc-bromine flow batteries. These batteries are based on a similar concept to Vanadium Redox Flow batteries, but instead of Vanadium, the battery uses a zinc bromide electrolyte solution. The ZCell zinc-bromine flow battery is made from easily-recycled or reused components.
Zcell batteries can withstand harsh environments, especially when it comes to particularly hot temperatures. It carries the added safety benefit of being non-flammable. The battery can be discharged to 100% with no damage incurred or capacity lost, and has a lifespan of 10 years. The Zcell battery comes in 10kWh units and can be easily scaled to commercial, industrial and even grid requirements.
Stem is not classified as an energy storage manufacturer, but it has a unique solution that incorporates tier 1 lithium-ion battery suppliers such as Tesla, Panasonic and LG Chem. What makes Stem’s solution so unique is that its battery management system incorporates AI to decide when to shift load from the grid to the lithium-ion battery as well as when to charge the batteries. Power costs vary by the time of day, and the ideal solution is to avoid using grid power during peak times, instead using stored electricity during those hours. Then, one should use the grid to charge the battery during off-peak times.
Demand charges also play a significant role in utility costs. Those costs can be reduced by using energy storage technology. As Stem's website says, “Stem is the first to use artificial intelligence to learn, predict and optimize energy in real-time.” Their forward-looking, AI-based energy storage solution is geared towards larger commercial and industrial sized operations which are massive energy consumers.
Pellion Technologies is based in Massachusetts and is yet another MIT start-up, and they claim to be a leader and innovator in next generation energy storage technology. Though it's still early in the company's history, they have made a series of fundamental breakthroughs in terms of materials, chemistry, and battery cell design using magnesium ion.
The advantage of magnesium is that it has a much higher energy storage density than lithium ion, with a capacity equaling a whopping 1,000-watt hours per liter, compared with lithium ion’s 233-watt hours per liter. However, Pellion Technology's systems are still in a prototype stage, but should they reach commercial production, will serve as a game changer in energy storage.
Sakti has developed a solid-state battery cell with a high energy density. Their specific battery gives them the potential to increase the density of today’s most advanced liquid lithium-ion batteries while also being smaller, safer, and more reliable. Solid state batteries have solid electrodes and solid electrolytes, which lends them to having high energy density properties.
This is also what makes them more stable, reliable and longer lasting than their liquid battery counterparts. As of yet, their solid-state battery is still a prototype but can potentially be another significant disruptor in the industry.
Seeo is a California-based startup, and like Sakti they are working on solid-state battery technology. Seeo has also developed the next generation of lithium-ion batteries based on a nano-structured non-flammable polymer electrolyte called DryLyte.
What makes this battery unique is its energy density performance in a solid-state design optimized for increased safety, reliability and longer lifespan than existing lithium-ion batteries. They are currently targeting the electric vehicle and grid energy storage markets.