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Baby steps for EOS’ zinc batteries in US ahead of 40MWh project, company targets UK for 2020

Inside Eos' Znyth battery module. Image: Andy Colthorpe

EOS Energy Storage, makers of a novel zinc hybrid cathode battery technology, has supplied two 120kWh systems in the US and struck a partnership to investigate the application of the technology in the UK.

The company has touted the low cost potential of the aqueous, zinc devices for some time, with Energy-Storage.news reporting a claim from the company in 2017 that solar-plus-storage using the batteries could hit 10 US cents per kilowatt hour, having already set the price for a 1MW / 4MWh grid-scale system block at US$160 per kWh.

The company itself said back then that its DC battery could be 30% to 40% lower cost than a comparable lithium battery. Today, UK-based renewable energy company Bryte Energy said that the technology is “revolutionary in the industry and has the potential to be the most competitive and low-cost battery in the market”.

Bryt Energy, together with stationary storage company Connected Energy – which currently specialises in developing ESS from repurposed electric vehicle batteries – said it will collaborate with Eos to roll out a cost-competitive version of the US company’s zinc hybrid battery system for the UK commercial and industrial (C&I) market. After developing and testing the adapted battery systems, the trio wants universities to take up research, aiming that a commercialised version with EU certification could be ready next year. 

Duke Energy's McAlpine test centre in North Carolina now plays host to the Eos battery storage system alongside solar PV and other distributed energy equipment. Image: Businesswire

Modest new deployments hint at things to come

Eos has been working on the batteries since 2008 and has already netted some early grid-scale deployments, including a 1MWh system for a microgrid in the company’s home state of New Jersey at a wastewater treatment plant, while utility Engie said it would test a 1MW / 4MWh Eos ‘Aurora’-branded battery system to its “operational boundaries” in Brazil and Siemens was reported to be working with the company on system integration, all in 2017. As with other non-lithium battery chemistries such as vanadium flow batteries, the company has had to battle for recognition but Eos was selected by developer Convergent Energy + Power for a 10MW / 40MWh California project back in 2015 and Eos said this week that that project is still going ahead. Convergent was awarded the project by investor-owned utility Pacific Gas & Electric and the project still remains the “only non-Lithium energy storage technology contracted through California’s statewide procurement mandate AB2514,” Eos pointed out.

Now, utility Duke Energy in the US has installed an Eos 30kW / 120kWh system at its McAlpine test facility in North Carolina, DC-coupled with a grid-connected solar array. The system uses the DC-to-DC converter technology to eliminate losses and reduce the amount of required hardware versus AC-coupling via an inverter. Eos also claims its systems are non-hazardous and do not need fire suppression systems, which reduces associated operation and maintenance (O&M) costs and footprint and makes for easier project design as the system can be distributed around a site.

Clearly Duke Energy wants to reap the potential benefits of finding and testing system technologies that could lower the cost of storage. The utility said in October last year that it plans to plough some US$500 million of investment into battery storage in North and South Carolina.

“Duke Energy is actively deploying the technology in our communities as a way to enhance reliability, defer system upgrades and deliver operational benefits for all customers,” Tom Fenimore, Duke Energy business development manager, said as the Eos Aurora 2 system went into action at McAlpine.

Also this week, Eos said the University of California, San Diego, has deployed a behind-the-meter 30kW / 120kWh Aurora system which will serve an immediate commercial benefit, through reducing demand charges and managing energy consumption for commercial customers. This time delivered as an AC-integrated, plug and play solution, multiple-hour discharging of the battery can reduce consumption of electricity from the grid at peak times. Eos said integration of the 120kW system would help prepare the company for the 40MWh project ahead with Convergent. 

Eos battery stack. Image: Andy Colthorpe

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