IEEE Power & Energy Magazine - November/December 2017 - 39

Niche applications having favorable economics exist today,
and these applications are expected to broaden as capital costs
continue to decline and renewable penetration increases.
system, managing the variability at each plant will lead to a significant overbuild and lose the benefits of geographic diversity.
While a single solar PV plant will have significant variability on
a cloudy day, several plants dispersed across the region will have
significantly smoother output.
In short, using storage to balance a single plant may result
in injecting power at one point on the grid, while a nearby
storage system is withdrawing power at another plant location. Therefore, storage can be utilized as a broader system
asset, controlling frequency, voltage, ramp rate, and energy
shifting for the balancing area rather than just a single plant.

The Future for Energy Storage
and Renewable Integration
Battery energy storage will continue to play an increasing role
in power grids around the world. This will likely accelerate as
the costs of battery energy storage continue to decline, industry
learning and acceptance solidifies with continued development
of pilot projects, and the need for ancillary services increases
as the resource mix continues to evolve from a synchronous,
fossil-fuel-based grid to a future renewable-centric grid.
The recent increase in attention across the industry to battery energy storage should not detract from fundamentally
sound resource planning, grounded on the physical needs of
the grid and the economic needs of rate payers. Battery energy
storage is one form of grid flexibility that will enable a modernization of our electrical grid and the further adoption of renewable energy, but many others exist. Grid planners and operators
should first pursue the low-hanging fruit for system flexibility,
before pursuing relatively capital-intensive battery energy storage projects. These other forms of flexibility include, but are
not limited to, the following:
✔ conventional thermal unit flexibility [improved cycling (on/off) performance at lower cost, reduced minimum stable operating levels, and faster ramp rates]
✔ hydro unit flexibility and coordination with wind and
solar output levels
✔ advanced inverter functionality from wind and solar resources, both at the utility-scale and distribution levels
to include bidirectional control and communication,
low-voltage ride-through, volt-var support, frequency
ride-through, fast frequency response, and regulation
✔ demand response, including energy shifting and, for
essential reliability services like fast frequency response, regulation and replacement reserves
✔ increased demand-side price responsiveness via timeof-use or real-time pricing
november/december 2017

✔ increased cooperation and coordination among neigh-

boring balancing areas and across interconnections
via high-voltage dc lines.
Battery energy storage will be one of many valuable
technologies and resources that will help facilitate additional renewable penetration and modernize the grid. Most
bulk power systems today do not require large-scale energy
shifting from one time period to another, due to excess
renewable generation or significant on-peak versus off-peak
electricity prices. Long-term trends in the power industry
may favor future deployment of multihour (4-6-h) duration
battery systems, but in most places no near-term need has
cropped up. Thus, near-term battery energy storage deployments should continue to focus on providing essential grid
reliability services in regions where the value is highest,
such as island and remote grids, municipal and co-op
electricity providers, and areas with high renewable penetration. Eventually, as the power system modernizes and
renewable penetration increases, battery energy storage will
play a more significant role in energy, capacity, and ancillary service markets.

For Further Reading
DOE global energy storage database. Office of Electricity Delivery and Energy Reliability, Sandia National Laboratories
and Strategen Consulting. [Online]. Available: http://www
.energystorageexchange.org/
(Jan. 2015). Battery storage for renewables: Market
status and technology outlook. International Renewable
Energy Agency. [Online]. Available: http://www.irena.org/
Docu mentDownloads/Publications/IRENA_Battery_
Storage_ report_ 2015.pdf
(Dec. 2016). Levelized cost of storage analysis 2.0. Lazard.
[Online]. Available: https://www.lazard.com/perspective/
levelized-cost-of-storage-analysis-20/
The value of energy storage for grid applications. National
Renewable Energy Laboratory. [Online]. Available: http://
www.nrel.gov/docs/fy13osti/58465.pdf

Biographies
Derek Stenclik is with GE Energy Consulting, Schenectady,
New York.
Paul Denholm is with the National Renewable Energy
Laboratory, Golden, Colorado.
Babu Chalamala is with Sandia National Laboratories,
Albuquerque, New Mexico.
p&e

ieee power & energy magazine

http://www http://www.energystorageexchange.org/ http://www.irena.org/ https://www.lazard.com/perspec http://http:// http://www.nrel.gov/docs/fy13osti/58465.pdf

Table of Contents for the Digital Edition of IEEE Power & Energy Magazine - November/December 2017