Chemical Engineering December 2011 - 19

A123 Systems
Newsfront
TRANSPORTING ENERGY
THROUGH TIME
THROUGH TIME
A portfolio of new energy-storage technologies
is poised to tackle applications
on the next-generation power grid
M
odernizing the world's power
grids represents a key infrastructure
goal for economic
growth. Large-scale, energystorage
technologies offer the opportunity
to optimize the efficiency of the
next-generation power grid and extend
its capabilities. Renewed attention on
energy storage systems for the grid
has given rise to a host of emerging
technologies aimed at more effectively
transmitting electricity not only across
space, but also through time.
Several factors have fostered development
of new electrochemical and
mechanical strategies for large-scale
energy storage systems that can collect
generated electricity and store
it for discharging to the grid when
needed. Among the major drivers are
the high capital costs associated with
managing peak power demand, as well
as the increase in grid modernization
initiatives.
Meanwhile,
deployment
of wind and solar power are increasing,
making the grid more sensitive
to the variability inherent in nature,
and thus strengthening the need for
energy storage systems.
Currently, 99% of existing gridenergy
storage is achieved through
" pumped hydro, " a term used to describe
the strategy of pumping water
to higher elevations at times of low
demand, and releasing the water
through turbines to produce electricity
when demand is higher. Pumped
hydro has been relatively effective
for years, but its use has specific site
requirements, and plants are highly
capital-intensive and may have environmental
drawbacks.
These drawbacks, coupled with grid
modernization and renewable energy
growth, have spurred considerable effort
by engineers in many disciplines to
commercialize newer storage technologies
- such as flow batteries, lithiumion
batteries, compressed-air energystorage
systems and flywheels - that
are more broadly applicable and offer
higher performance for specific applications.
Meanwhile, questions remain
about which storage technologies can
be deployed cost-effectively, how best
to match technologies to a variety of
grid applications, and about how the
economic and regulatory environment
can be adjusted to allow storage technologies
to fulfill their potentials (for
more, see the online version of this article
at www.che.com).
FIGURE 1. Integration of wind power is
a major application for grid energy-storage
technologies, such as the planned
Li-ion battery facility shown here
Grid-storage needs are varied
Energy storage systems have the potential
to provide a range of benefits
to the entire electrical system, from
power generation to transmission and
distribution, an ultimately to the enduser.
According to U.S. Dept. of Energy
(DOE; Washington, D.C.; www.energy.
gov) and independent analysts, the size
of the grid-energy storage market may
be over $1.5 billion today, and has been
forecasted to grow to more than $35
billion by 2020.
The evolution of the modern power
grid, as well as the degree to which
renewable energy technologies are deployed,
is highly intertwined with the
development of economical grid-energy
storage systems. Among the most frequently
discussed applications of energy
storage involving power generation
is off- to on-peak shifting, where
storage devices would be charged at
the site of intermittent renewable
energy sources, and discharged into
the grid during on-peak periods. This
would enable increased penetration of
wind and solar power into the power
grid. Another key generation-related
application is in grid frequency regulation,
where short-term fluctuations
in energy supply and demand are
smoothed by storing energy when supply
exceeds demand, and discharging
CHEMICAL ENGINEERING WWW.CHE.COM DECEMBER 2011 19
http://www.energy http://www.che.com http://WWW.CHE.COM
Chemical Engineering December 2011

Table of Contents for the Digital Edition of Chemical Engineering December 2011
