Flywheel energy storage: only in museums?

What comes to your mind when you think of flywheels? I assume you probably think of rollercoasters or something you have seen in a museum. Believe it or not, with Mergeflow we found companies and energy projects that develop and use flywheels for energy storage.

Flywheel energy storage can help overcome limitations of intermittent energy supplies, such as Solar PV or Wind Turbines, that do not produce electricity 24/7.

Here are some companies that we found with Mergeflow:

– Chakratec develops flywheel energy storage systems (kinetic batteries). Chakratec raised $2M in funding in 2015 from China-based ZZRunner. At the heart of Chakratec’s system there is an array of flywheel storage units that enable robust and fault tolerant storage. Applications include charging stations for electric vehicles, for instance. Here is a video Their technology is applicable in different applications, such as storage for EV Charging Stations (cf. this demo video).

Active Power has more than 20 years of experience in the field; they started filing patents in 1997. They continue filing patents, as shown in the graph below.

Active Power patents


Amber Kinetics has developed a technology that extends the storage duration of flywheels from minutes to four hours. The company has recently been on CBS News, discussing flywheels’ potential for energy storage solutions. Funded in 2009, Amber Kinetics has filed 10 patents so far.

Amber Kinetics patents


Beacon Power offers flywheel-based energy storage systems that correct frequency imbalances and reduce system fuel consumption. Beginning in 1997, their flywheel system has delivered over 7 million operating hours so far, according to their website. Beacon Power also has received research funding from the SBIR Program, a US federal funding program for SMEs.

Beacon Power fundings


– Another company, PowerTHRU, designs flywheel storage systems that provide voltage stabilization for power quality and recycling applications. They delivered over 500 flywheel systems to the U.S. Air Force as part of the ICBM Security Modernization Program (cf. here). Mergeflow indicates that PowerTHRU has received increasing coverage by industry news sources, starting around end-2015: