Frontier of Energy Storage

The Holy Grail

Published In: EnergyBiz Magazine January/February 2014

By Troy DeVries and Joseph Carbonara

When Thomas Edison flipped the switch to his first dynamo in the 19th century, the genius-wizard

launched a multitrillion-dollar industry. Making and delivering electricity leaped from infancy to

cocky adolescence with speed unseen in new ventures.

Edison and his fellow entrepreneurs toyed with but never mastered storing electricity on a mass

scale.

Depending on the utility pundit, energy storage could be the next frontier in electricity. This is

because utility infrastructure is built to accommodate the highest energy usage of the year, typically

the hottest day of the summer. That means an investment in infrastructure to accommodate, for a

brief period, energy usage that can be as much as three times what it is on average.

Energy storage in general has been kind of a Holy Grail for utilities. Generation and demand are

instantaneous. Utilities are looking at ways to buffer them.

“Energy storage is no longer an idea and a theory — it’s actually a practical reality,” Steve Hellman,

president of Eos Energy Storage, recently told The New York Times. “You’re seeing a lot of

commercial activity in the energy storage sector.”

In the spring of 1963, Con Edison proposed a pump-storage facility on Storm King Mountain.

The technology was simple: Approximately 8 billion gallons of water would be pumped 2 miles from

the Hudson River to the top of the mountain 50 miles north of New York City every night when

electric costs were low. The water would be stored in a reservoir and released during the day,

hurtling through turbines, when electric costs were at their peak.

Con Edison argued that the growth of air conditioners and other appliances required considerably

more, and affordable, electricity.

When Con Edison’s plans were published, opponents argued that the plan would cause the death of

a scenic canvas for Hudson River School artists, destroy a striped bass breeding ground and create an

eyesore that would change the river forever.

Opposition in courtrooms and riverfronts helped defeat the company’s plan for pump storage seven

years after it was born, and the story of Storm King Mountain gave birth to the environmental law

movement.

Environmental sensibility has matured in 50 years. The quest for safe energy storage has kept pace.

An Eos Energy Storage battery, scheduled to be installed in a Con Edison facility early in 2014, was

chosen for its safety. The zinc-air core is its cornerstone, as are its nontoxic, stable chemicals. The

exact location has not been chosen yet. It will depend on size and availability of an appropriate

space and interconnection considerations.

Con Edison had rejected a hydrogen battery for its potential volatility and the New York City Fire

Department’s reluctance to certify its safety. The company considered using the hydrogen battery in

a remote, non-urban community, but even rejected that because of safety and environmental

concerns.

Eos’ Znyth cells are in the laboratory, delivering capacity and energy efficiency that make them

attractive for a closer look by our R&D department. Unproven is the claim of Eos’ $160 per kilowatt-

hour price point and 30-year life. The cost and life of the Eos cells are the focus of Con Edison’s

research into energy storage.

Con Edison also has invested in a zinc-based battery research project from Urban Electric Power,

recently installed at the City University of New York to help reduce the Harlem school’s peak energy

demands. New York State Energy Research and Development Authority also is an underwriter of the

program.

Con Edison continues to review energy storage technologies as they are developed. A key feature for

our congested urban environment and possible installation within buildings is the use of nontoxic

chemicals and intrinsically safe technologies and chemistries. Also important are life cycles, cost-

effectiveness, maintenance requirements, size, efficiencies, discharge rate and depth of discharge.

Con Edison has been working closely with Eos during the development of their technology to ensure

that the final product fits the needs of the utility industry.

(Troy DeVries is Con Edison’s director of research and development and Joseph Carbonara is a project

manager in research and development at Con Edison.)