89. The Benefits of Flow Batteries Over Lithium Ion

The Benefits of Flow Batteries Over Lithium Ion Lithium-ion (Li-ion) is the most commonly talked about battery storage technology on the market these days, and for good reason. Li-ion batteries have a high energy density, and they are the preferred option when mobility is a concern, such as for cell phones, laptop computers, and electric vehicles. But there are different energy storage technologies that make more sense in other use cases. For example, iron flow batteries may be a better option for utility-scale power grid storage. An iron flow battery is built with three pretty simple ingredients: iron, salt, and water. “A flow battery has a tank with an electrolyte—think of it as salt water to be simple—and it puts it through a process that allows it to store energy in the iron, and then discharge that energy over an extended period of time,” Eric Dresselhuys, CEO of ESS Inc., a manufacturer of iron flow batteries for commercial and utility-scale energy storage applications, explained as a guest on The POWER Podcast. Iron flow batteries have an advantage over utility-scale Li-ion storage systems in the following areas: • Longer duration. Up to 12 hours versus a typical duration of no more than 4 hours for large-scale Li-ion systems. • Increased safety. Iron flow batteries are non-flammable, non-toxic, and have no explosion risk. The same is not true for Li-ion. • Longer asset life. Iron flow batteries offer unlimited cycle life and no capacity degradation over a 25-year operating life. Li-ion batteries typically provide about 7,000 cycles and a 7- to 10-year lifespan. • Less concern with ambient temperatures. Iron flow batteries can operate in ambient conditions from –10C to 60C (14F to 140F) without the need for heating or air conditioning. Ventilation systems are almost always required for utility-scale Li-ion systems. • Lower levelized cost of storage. Because iron flow batteries offer a 25-year life, have a capital expense cost similar to Li-ion, and operating expenses that are much lower than Li-on, the co