Presentation at Massachusetts Sustainable Communities and Campuses Conference on March 17, 2017

1. ©2017 NEC Energy Solutions,Inc. All rights reserved.
INTRODUCTION TO ENERGY STORAGE
Philip Fischer
NEC Energy Solutions
pfischer@neces.com
1

2. ©2017 NEC Energy Solutions,Inc. All rights reserved.
• The electricity grid is a complex
system that produces and delivers
electricity to end users
• The grid can be thought of as
composed of these parts:
– Generation (Electricity Producers)
– Transmission& Distribution
– Load (Electricity Consumers)
• The grid was designed with these
characteristics in mind:
– Electricity flows from Generation
to Load and not in the other direction.
– Generation must alwaysmatch Load; there is no storage
Introduction
Electricity Grid Basics
2

3. ©2017 NEC Energy Solutions,Inc. All rights reserved.
• The grid must be supplying electricity
to customers at all times.
• The grid must be operated safely and
minimize hazard to people and
equipment at all times.
• The grid must stay in balance at all
times.
How does the grid work?
Electricity Grid Basics

4. ©2017 NEC Energy Solutions,Inc. All rights reserved.
• Today’s grids require more flexibility to
address:
– Increased renewable generation
– Changing load patterns
– Aging transmissionand distribution network
• Energy storage in the grid is a powerful tool
– Increase capacity utilization for generation,
transmission, and distribution infrastructure
Preparing Grids For A Renewable Future
Adding flexibility, efficiency, and reliability
Why Energy Storage for the Grid?

5. ©2017 NEC Energy Solutions,Inc. All rights reserved.
• In our context, Energy Storage refers to the ability to hold
electricity safely, reliably, and economically for future use.
• Mediating between variable sources and variable loads.
• Decoupling production from consumption.
• Reducing price volatility.
• Enabling 100% renewable generation.
• Making the grid more efficient.
• Increasing reliability.
• Today, only about 2.2%of electricity is stored world-wide(1)
What is Energy Storage?
Introduction to Grid Energy Storage
Adapted from: Introduction to Bulk Pow er Systems, B. Kirby, EUCI course, Jun 8-9 2009, Washington DC
(1) Source: “AnnualElectric Generator Report”, 2011 EIA – Total Capacity 2009; US Energy Information Administration, Form EIA-860, 2011.

6. ©2017 NEC Energy Solutions,Inc. All rights reserved.
• Energy Storage moves energy through time
• With Energy Storage, the grid does not have to instantly balance generation with
consumption
• It fundamentally changes system resource adequacy and the system planning
paradigm
• It provides System Operators a powerful new tool for system security
• It is a game-changer for the electricity grid…
What is Energy Storage?
Introduction to Grid Energy Storage
With Energy Storage, we need to think about the
electricity grid in new ways!

7. ©2017 NEC Energy Solutions,Inc. All rights reserved.
• There are many types of energy storage
– Pumped Hydroelectric Storage (PHS)
– Compressed Air Energy Storage (CAES)
– Flywheels
– Batteries!
• Lithium ion
• Lead acid
• Flow batteries
• Sodium beta alumina
• Also (less common)
– Supercapacitors
– Superconducting Magnetic Energy Storage (SMES)
What is Energy Storage?
Introduction to Grid Energy Storage
Other types of Energy
Storage:
FossilFuels
Probably the most abundant and
well known form of energy storage
– chemical energy storage in the
form of oil or gas.
Thermal Energy Storage
Storing Heat or Cold in molten salt
or ice to either generate electricity
or provide useful heat or cooling.
Power-to-Gas (PtG)
Using electricity to create
hydrogen gas, with possible
methanization step, and feeding it
into the gas grid
Note: These types will not be
covered in this training module.

8. ©2017 NEC Energy Solutions,Inc. All rights reserved.
Battery Energy Storage
General layout of a battery energy storage system for the grid
Battery Energy StorageSystems need
power conversion equipmentto connect
to the grid and do not make useof any
turbine or other generating equipment,
unlike PHS or CAES.
While the transformers, power
conversion systems, breakers and
switches areall fairly common, the
differentiating characteristics are
primarily in the storage device, and in
systemdesign, which ties all the major
components to the storagedevice in a
seamless, safeand reliable system.
There are many battery energy storage
sites in operation today as both pilot
projects and commercial revenue
projects… butmore on that later.
The next slide will detail the different
types of battery technologies.

9. ©2017 NEC Energy Solutions,Inc. All rights reserved.
Grid edge energy storage
C&I advancedenergy
management
• DCM, Triad, etc.
• PV enhancement (time
shifting, ITC )
• Demand Response
• Black start/back up
• Grid Services
Utilities (T&D)
Utility Scale DER
Muni/CoOp
• Peak shaving
• Local renewables support
• Voltage/VAR support
• Community ESS
• Distributed ancillary service
Custom/microgrid
• Grid-Tied projects
• Remote/island microgrid
energy storage
• Hybrid Microgrid
(Renewables + Genset +
Storage)
• Utilities
• Solar
• Targeted Grid
• Developers
• Others
Front of the Meter (FTM) Behindthe Meter (BTM) “No Meter”
• Developers
• Aggregators
• Community
• C&I Enterprises
• MUSH Market
• Lots and lots more energy
users & ESCOs
• Secure Power
• Mission critical
• Process
• Government
• C&I Enterprises
• MUSH Market
• Lots of others
• Resilient Solar
• Hybrid Microgrid
• UPS Operation
• Peak Shaving
• Resource
Capacity Adequacy
• VPP

10. ©2017 NEC Energy Solutions,Inc. All rights reserved.
• Behind-The-Meter indicates that the application is located on the customer side
of the electricity meter
What does Behind-The-Meter mean?
Behind-The-Meter
Electricity meter
Measures the electricity usage
of a customer
Electricity Customer
Could be a home, office
building, or a factory
Electric Utility
Responsible for serving
customers electricity
“Utility side of the
meter”
“Behindthe meter”

11. ©2017 NEC Energy Solutions,Inc. All rights reserved.
• Value streams from savings include:
– Demand charge reduction
– PV self consumption
– TOU rate arbitrage
• Value streams from revenue can include:
– Demand response
– Frequency regulation
– Other Grid Services
• Value streams from incentives can include:
– Federal Solar ITC (30% of capex with performance restrictions)
– CA SGIP ($360/kWhstorage changesdepending on ITC claim, has performance restrictions)
– MA StorageAdder for PV ($0.03/kWhgeneration , proposal only at this time)
– Etc.
• Value from resiliency and sustainability
• Many more…
• All value streams differ depending on site location, tariffs, and performance
BTM Value Streams

12. ©2017 NEC Energy Solutions,Inc. All rights reserved.
For more info:
• Energy Storage Initiative (ESI)
– http://www.mass.gov/eea/energy-utilities-clean-tech/renewable-
energy/energy-storage-initiative/
• Energy Storage Association
– http://energystorage.org/energy-storage
• Phil Fischer – NEC Energy Solutions
– pfischer@neces.com