Page 70 - North American Clean Energy May June 2015

energy storage

Behind The Meter

Energy storage in NYC saves money and delivers grid beneits
by Erick Petersen

Figure 1. Power usage graph from the Barclay Tower showing demand capping in efect.

Image 2. he energy storage platform is

technology agnostic – utilizing the power
conversion (inverter) and battery technology
that is most appropriate for the energy
storage application and business case.

Image 1. he Barclay Tower in Manhattan.
Figure 2. Block diagram of the system installed at the Barclay Tower

Utility deregulation creates market opportunity
the impact of high power draw from all users during a critical power event or a summer afternoon that
he deregulation of the power industry is providing opportunities for the customer side of the drives air-conditioning load. Both programs are available for an incentive from Con Edison, NYSERDA,

meter load management that have never existed before. he emerging variable pricing structures or NYISO, depending upon the program speciics. Since the Barclay Tower is under a Standby Power
have the potential to create real value for both the utility and their customers. Power companies can Rate, it can skip a days worth of typical demand reduction and change operation to support these
use them to balance the load on existing generation, transmission and distribution equipment, and types of critical power events with minimal inancial input. his type of lexibility is one of the reasons
consumers can use the fact that rates vary to shop for the “best deal” to lower their energy expense. behind-the-meter energy storage systems are poised for rapid deployment in the NYC market.

But, to reap the full beneits, commercial and industrial customers need to deploy systems to fully During one critical period: the week of July 15, 2013, when the city was experiencing a heat wave
manage how they buy and use energy.
and NYISO and Con Ed were calling for signiicant load reductions, the system in the Barclay Tower
Power users would like to have the lexibility to buy energy at lower rates, but this often means went into demand response mode, delivering a 100 kW reduction of the building’s 500 kW peak load

buying it at times when other users don’t want it – typically, the middle of the night. Changing their and maintaining this level of reduction for a period of four hours as required in order to participate
business hours is not practical, and they don’t want to constrain their operations in the middle of in the NYISO load reduction program. he system was able to use energy that was purchased of-
the day while rates are high. An emerging and compelling solution is energy storage. If a facility can peak at 6 to 8 cents per kWh overnight to reduce building load when prices had increased to 28 to
buy energy when it is at the lowest cost, store it, and use it when energy is more costly, that facility 31 cents per kWh in the heat of the day. Glenwood saved money, was able to keep 100 kW of load

has the potential to save a good deal of money.
operational since it was supplemented by the stored energy, and the utility experienced lower de-
Another dynamic involves opportunities to capitalize on market incentives that require reduction mand at a critical time.
in consumption to gain inancial beneits. Some utilities are paying customers to reduce their loads Also, if the Barclay Tower faces another extended outage like what occurred during Hurricane
at critical times. With the ability to release stored energy to meet a portion of the building load, a Sandy, the critical power support from the energy storage system will supply power to circuits that

facility can reduce its consumption of grid power and capture the rewards while conducting “busi- provide water, emergency lighting and the service elevator.
ness as usual.”
he above examples illustrate how Intelligent Energy Storage helps Glenwood Management de-
Glenwood Management, an owner of high-end luxury apartments across New York City, is a rive multiple economic beneits from this unique installation. “With our intelligent energy storage
visionary and early adopter of intelligent energy storage. For the last four years, they have been system, we don’t need to reduce the total consumption,” said Josh London, Glenwood’s vice presi-

exploring how emerging technologies might save them money in the emerging transactive energy dent of management. “We can change our mode of usage and select the operational mode that saves
market that has resulted from utility deregulation in New York.
the most money for that day. We can store energy more aggressively at night and on weekends and
save a signiicant amount of money.”
Testing the beneits of energy storage

Glenwood installed one of the earliest and largest behind-the-meter (BTM) energy storage systems A look inside the energy storage system
in the country in August of 2012 at the Barclay Tower, a 58-story luxury building in the Tribeca A block diagram of the behind-the-meter energy storage system is shown in Figure 2. he system in-
section of Downtown Manhattan (Image 1). he intelligent energy storage system, contained two corporates three core elements with the key element being a cloud-based control system that applies
megawatt-hours of storage and qualiied them to receive Con Ed’s standby electrical rates because advanced algorithms to automate and optimize decisions about energy utilization in the building. he

the storage represented in excess of 15 of the building’s peak electrical load. his means that the software tracks and predicts the price of power to identify savings opportunities, and measures real-
Barclay is charged a lat rate based on the building’s historic peak load, plus a daily demand charge time energy demand at the building level. he system ensures that stored energy can be immediately
based on weekday usage between 8 AM and 10 PM.
deployed to respond to demand, either from increased needs locally, or driven by utilities’ demand re-
With more than two years of operating results, the team at Glenwood has had the opportunity to sponse programs, with no impact to the building’s operation or the living conditions for those working

explore and test a number of operating models for the system. he energy storage solution guides inside it. he system’s analytics leverage cloud-based data storage that is inherently scalable and highly
daily operations of the building by downloading day-ahead pricing information from the New York reliable, with data being replicated throughout the system and secured via encryption.
Independent System Operator (NYISO) and using this data to make decisions on the next day’s At the core of the system’s hardware architecture are the power conversion and energy storage
operations. One alternative is to limit the building’s demand during operational hours (demand cap- sub-systems. he power conversion system accepts and conditions power from multiple DC and AC

ping), satisfying the need for high-cost power with energy purchased earlier at a lower rate. Figure
input sources. he energy storage system manages the energy storage battery array (Image 4). he
1 shows how demand capping lattens the Barclay’s peak power requirements on the utility, saving system is technology agnostic and capable of adapting to future advances in battery chemistries and
money without causing any change in the building’s operation or impact on its residents.
power conversion technologies.

Alternatively, the system can support a diferent type of operation during critical power events or
the summer air-conditioning season (typically June through September). For both of these types of Erick Petersen is the vice president of marketing and business development for Demand Energy
load reduction programs, the storage system can be conigured to release a constant power output for
a set amount of time, typically four hours in the afternoon. his type of load reduction helps lessen
Demand Energy | www.demand-energy.com

70 nacleanenergy.com
MAY/JUNE 2015