1. 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.

2. 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 kilowatthour 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, costeffectiveness, 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.)