Battery energy storage systems are one of the fastest growing technologies in the sustainable energy industry. Energy storage systems have become widely accepted as efficient ways of reducing reliance on fossil fuels and oftentimes, unreliable, utility providers. A battery energy storage system is the ideal way to capitalize on renewable energy sources, like solar energy. The adoption of energy storage systems is on the rise in a variety of industries, with Wood Mackenzie’s latest US Energy Storage Monitor report finding 476 megawatts of storage was deployed in Quarter 3 of 2020, an increase of 240% from Quarter 2.
All energy storage systems use batteries, but not the same kind. There are many different types of batteries used in battery storage systems and new types of batteries are being introduced into the market all the time.
These are the main types of batteries used in battery energy storage systems:
- Lithium-ion (Li-ion) batteries
- Lead-acid batteries
- Redox flow batteries
- Sodium-sulfur batteries
- Zinc-bromine flow batteries
The most common type of battery used in energy storage systems are lithium-ion batteries. In fact, lithium-ion batteries make-up 90% of the global grid battery storage market. A Lithium ion battery is the type of battery that you are most likely to be familiar with. Lithium-ion batteries are used in cell phones and laptops.
A lithium ion battery is lightweight and will likely be more expensive than some of the other options out there.
According to the U.S. Department of Energy’s 2019 Energy Storage Technology and Cost Characterization Report, for a 4-hour energy storage system, lithium-ion batteries are the best option when you consider cost, performance, calendar and cycle life, and technology maturity.
Lead acid batteries are the most widely used rechargeable battery technology in the world and have been used in energy storage systems for decades. Lead acid batteries may be familiar to you since they are the most popular battery for vehicles. They have a shorter lifespan than other battery options, but are the least expensive.
Lead acid batteries have a well established recycling system and are the most widely recycled batteries. According to the Energy Storage Association, lead acid batteries are extremely eco-friendly; more than 90% of their material is recovered and the average lead battery is made-up of more than 80% recycled materials.
According to the Department of Energy report, lead-acid batteries have high technology and manufacturing readiness levels, but the cycle life is less than three years assuming one cycle per day.
On the other hand, The Energy Storage Association says lead acid batteries can endure 5000 cycles to 70% depth-of-discharge, which provides about 15 years life when used intensively. The ESA says lead acid batteries are a good choice for a battery energy storage system because they’re a cheaper battery option and are recyclable. They are also safer than some other chemistries because their active components are not flammable.
Redox flow batteries
Redox flow batteries have chemical and oxidation reactions that help store energy in liquid electrolyte solutions which flow through a battery of electrochemical cells during charge and discharge.
According to the book “Advanced Membrane Science and Technology for Sustainable Energy and Environmental Applications” redox flow batteries minimize environmental risk and improve response time to demand. Instead of the typical battery where the electrolyte system is encapsulated between electrodes and limited to the volume of the secondary battery, the electrolytes in a redox flow battery are circulated from a reservoir tank.
During discharge, an electron is released from the negative side of the battery and is eventually accepted through a reduction reaction on the positive side of the battery.
According to the Department of Energy report, rapid improvements are expected in the overall cost, performance, life, technology readiness levels, and manufacturing readiness levels, but the round trip efficiency of redox flow batteries is low.
The Energy Storage Association (ESA) says RFB batteries are best for large projects that require power in the tens of kilowatts to tens of megawatts range. According to the ESA, storage tanks and flow controls are inexpensive and easy to scale and electrochemical stacks offer power ratings in the tens to hundreds of kilowatts.
Sodium-sulfur batteries must be kept hot, 572 to 662 degrees Fahrenheit, in order to operate, which can obviously be an issue for operation, especially at a place of business. The round trip efficiency is high – in the 90% range.
Sodium-sulfur batteries are made up of molten sulfur and molten sodium, the sulfur is the positive, while the sodium is the negative. Sodium based batteries are more sustainable than lithium-ion batteries since there is an abundant amount of sodium in the earth’s crust.
The Energy Storage Association says this technology is being used currently in Japan and Abu Dhabi.
Zinc-bromine flow batteries
The zinc-bromine battery is a hybrid redox flow battery. The Energy Storage Association says most of the energy in these batteries is stored by plating zinc metal as a solid onto anode plates in the electrochemical stack during charge.
Zinc-bromine is pumped past both the negative and positive. During charge, zinc is deposited at the negative side, while bromine is present at the positive side. The electrodes are separated by a microporous plastic film.
According to the U.S. Department of Energy, zinc-bromine batteries offer great promise in terms of cost and life, but their technology and manufacturing readiness levels are currently low.
Battery energy storage system adoption is expanding at a rapid rate and so are the technologies that power the systems. New types of batteries are being developed constantly.
There are also non-battery type technologies being used in energy storage systems:
- Pumped storage hydropower (PSH)
- Compressed air energy storage (CAES)
Check out our YouTube video on Energy Storage! Learn how a battery storage system works and how it can benefit your business.
Energy storage adoption is growing for a reason. The technology allows businesses and organizations to be energy-dependent, no longer tied to their local utility and its downfalls, including power outages and high energy costs.
Energy storage is the future and now is the time to reap the benefits of the technology and renewable energy. The longer you wait to gain energy independence, the longer you spend more than you should on your energy bill. We want to use our decades of experience in the energy storage solutions to help you achieve your sustainability and financial goals. Please reach out to us or call us directly at 800-834-8737.