Compliance Ain't Optional:
NEC, UL, IEEE, Energy Storage & Microgrids
Rob Wills, Intergrid, LLC
Temple, NH, rwills @ intergrid.us
About the Presenter..
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Renewable Energy since 1982
Codes and Standards
Power Electronics & Inverters
Chaired NEC Committees on
Microgrids
NREL - Silicon Carbide-Based Inverters for
Intermediate Wind Applications
Single & Three Phase Inverters 20-50 kW for
Wind and Storage. Variable Speed Drives
(VFD) as active front-end.
CIP Program
Regulatory Landscape
UL Stds
IEEE Stds
Equipment
Design &
Testing
Operation &
Interaction
NEC
Installation &
Electrical Interface
Small Wind Codes and Standards
UL Stds
IEEE Stds
UL 6142
Small Wind
Turbine Systems
(also UL 1741)
IEEE 1547
Interconnecting
Distributed
Resources
with Electric
Power Systems
NEC
NFPA70
National Electrical Code
NEC Article 694 – Wind Electric Systems
The U.S. National Electrical Code (NEC), or NFPA 70, is a
regionally adoptable standard for the safe installation
of electrical wiring and equipment in the United States. The
NEC, while having no legally binding regulation as written,
can be and often is adopted by states, municipalities and
cities in an effort to standardize their enforcement of safe
electrical practices within their respective jurisdiction. From
Wikipedia
NEC Article 694 – Wind Electric Systems
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Article 694 has been in the NEC for six years now.
Started as “Small” Wind, developed into “All” Wind.
Three-year cycle; next edition is 2017.
Public comment stage for the 2017 cycle opens July
17, ends September 25.
• 2017 – No major changes (but PV & Rapid Shutdown!)
$90 Paper
or PDF
$150 Paper
or PDF
694.1 Scope – Implications
Large wind is now subject to local electrical inspection
694.1 Scope – Implications
IPP = NUG ≠ UTILILITY
NEC Article 694 – 2014 Requirements
694.7(B) Equipment
Wind electric systems equipment, sub-assemblies and components shall be
identified and listed for the application.
694.23 Turbine Shutdown.
(A) Manual Shutdown. Wind turbines shall be required to have a manual
shutdown button or switch. Exception: Turbines with a swept area of less
than 50 m2…
694.10(A) Wind Turbine Output Circuits.
For wind turbines connected to one- and two-family dwellings, turbine output
circuits shall be permitted to have a maximum voltage up to 600 volts. (Other
occupancies can be 1000V and above)
NEC Article 694 – Your Representatives
Dr. Robert Wills PE
rwills @ intergrid.us
603-801-4749
Robert Preus PE
robert.preus @ nrel.gov
303-384-7284
Energy Storage
Business Models for Battery Storage
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Emergency Backup Power (Today)
Off-Grid Applications (Today)
Demand Response (Today at Commercial Scale)
Self Consumption / Time Shifting (Coming)
Energy Arbitrage (Coming)
Interactive Microgrids (Coming)
Regulatory Landscape
Primary Codes and standards:
• NFPA70 - National Electrical Code
Articles 705 & 710 (Standalone
Systems)
• UL9540 – Standard for Energy
Storage Systems and Equipment
• Many UL Sub-Standards (UL1973
– Stationary Batteries, UL1741 –
Inverters)
• IEEE1547 (Grid Interconnection) &
IEEE2030 (Smart Grid)
NEC
UL Stds
IEEE Stds
How About Lithium?
Boeing chose a particularly risky type of
chemical makeup in its lithium ion battery, one
that provides more power but does not stand
up well to overheating [Lux Research]
• UL 1642 - Lithium
Batteries
• United Nations (UN)
Section 38.3 - Transport
of Dangerous Goods
MICROGRIDS: WHY?
http://www.greentechmedia.com/articles/featured/resiliency-how-superstorm-sandy-changed-americas-grid
Microgrid / ESS Markets
• Adding storage to grid-connect PV
systems for backup power.
• ESS as an alternative or addition
to standby generators.
• Customer load leveling and
renewable generation timeshifting.
• Utility demand response and
ancillary services.
• Stand-alone / Remote
applications.
Regulatory Landscape
Primary Codes and standards:
• NFPA70 - National Electrical Code
• IEEE 1547.4 - Guide for Design,
Operation, and Integration of
Distributed Resource Island
Systems with Electric Power
Systems
• IEEE 2030.7 Microgrid Controllers
NEC
UL Stds
IEEE Stds
Two Interest Groups
Two Definitions
Utilities (& DOE)
A microgrid is a group of interconnected loads
and distributed energy resources within clearly
defined electrical boundaries that acts as a single
controllable entity with respect to the grid. A
microgrid can connect and disconnect from the
grid to enable it to operate in both gridconnected or island-mode (U.S. Department of
Energy Microgrid Exchange Group, 2010).
Others (e.g.
Navigant Research)
This Navigant Research report analyzes the
global market for microgrids in five key
segments (commercial/industrial,
community/utility, campus / institutional,
military, and remote) and two new subsegments (grid-tied UDMs (Utility
Distribution Microgrids) and DC microgrids).
We need a broader definition
Present Technology
Multi-mode Inverters
Some problems with the multimode approach are:
• Only a subset of building loads are supported
• Essential loads have to be rewired to an emergency sub-panel
• Paralleling multiple units becomes awkward; they all have to be in the same location
• The transfer switch has limited capacity and functionality.
• Integration with renewable energy sources is complicated (dc coupling).
Microgrid Concepts
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Energy storage systems (ESS) become separate integrated entities.
Multiple ESSs can be installed if required.
Interconnection is via an Island Interconnection Device (IID).
Local sources are AC-coupled to the ESSs and the grid.
Off the shelf inverters and micro-inverters can be used.
All facility loads can be carried; no rewiring or sub-panels are required.
Contact:
Dr. Rob Wills, PE
Intergrid
PO Box 48
Temple, NH 03084
603-801-4749
rwills @ intergrid.us
Allan Villiers, 1929
PortandStarboard.com