Distributed Generation

Safe Work Procedures

Griffin Reilly

Section Manager

Targeted Demand Management

Energy Efficiency and Demand Management

Consolidated Edison Company of New York, Inc.

Customers Infrastructure Service Territory

Electric 3.3 million

(2.4 Network)

One of the world’s

largest UG systems

All 5 boroughs and

Westchester County

Gas 1.1 million 4,333 miles of gas

mains and services

3 out of the 5 boroughs

and Westchester County

Steam 1,760 World’s largest

district steam system

Manhattan below 96th

Street

Con Edison System

Con Ed Solar Map

Solar Installations at Con Edison

Types of Distributed Generation

Spinning – Breaker Isolated Inverter Based

• Combined Heat and Power

• Micro-CHP

• Diesel Generators and other

Reciprocating Engines

• Microturbines

• Solar

• Wind

• Batteries

• Fuel Cells

• Flywheels

Safety of DG has been Standardized L

ocal

Sta

te

N

ati

on

al

T

ests

Sta

nd

ard

IEEE 1547

(No Inherent Authority)

Product and Installation

Requirements

Grid Interconnection and

Functional Requirements

UL 1741 and IEEE P1547.1

(Listing and Certification Test)

National Electric Code

(Voluntary)

State Codes/Laws

(selective adoption of NEC)

Local Municipal Codes

NERC / FERC

State / PSC Utility Laws

Utility Connection

Agreements

New York State Standardized

Interconnection Requirements (SIR)

• Complete Interconnection Process

Description

• Customer and Utility

Reference

• Application Requirements

• Timeline Requirements

• Protection and Testing

Requirements

• Issued by New York State Public

Service Commission

Information is Critical

Training is Paramount

Grid Connected Solar Photovoltaic System

Basic Elements

• Photovoltaic Panel

• Inverter/Micro-Inverter

• Production Meter

• Disconnect Switch/Breaker

• Net Meter

Basic Elements

• Photovoltaic Panel

– 250W-350W capacity each

– 0-40V DC depending upon

sunlight exposure

– 5-10 Amps per panel

– Produce power any time

sunlight is on them

– Even with disconnect open,

Voltage is present at panel

– Wired in series to increase

DC Voltage and Amperage

Basic Elements

• Inverter

– Similar to vehicle inverter

– Converts DC to AC sine wave

– Sine wave created exactly

matches utility (unity PF)

– Acts like an amperage source

providing the house with kwh

– Integrated AC-DC disconnect

barrel switch on most models

– Multiple sizes and models can

be combined at one site

Basic Elements

• Micro-Inverter

– Inverter for each 1-2 panels

– Converts DC to AC prior to

leaving the roof

– No integrated disconnect

switch on the unit

– Separate disconnect switch or

breaker required to isolate

Inverter Safety Features

• All Inverters & Micro-Inverters are certified to UL-1741 and

IEEE-1547 national standards.

– Requires immediate shutdown on loss of utility reference signal.

– Inverter will not re-connect to restored grid until after 5-minute wait.

– Inverter will not produce power when one phase is lost.

– No voltage difference phase-phase, inverter will not produce power.

– Inverter has both Over-Voltage and Under-Voltage shutdown.

• MUST BE INSTALLED WITH CON EDISON APPROVAL

– Units found in the field that are not on M&S plate must be reported,

and approached with CAUTION!

– Units not certified may have been installed improperly

• Always Follow Work Procedures – Test Dead Before Work

Basic Elements

• Production Meter

– Measures AC kwh provided

by solar to the house panel

– Required by NYSERDA for

quality assurance

– Not read by Con Ed

– Can look similar to our

meters or be digital meters

– Often a source of confusion

for the homeowner

Basic Elements

• Disconnect Switch/Breaker

– Last piece of customer

equipment before load panel

– Isolates DG system from the

panel and meter

– Systems >25kw must have a

lockable disconnect switch

– Residential systems are

allowed to use a dedicated

breaker in the house panel

Basic Elements

• Net Meter

– Con Ed meter programmed

to record bi-directional flow

– Customer usage makes kwh

recorded go up as normal

– Solar export makes kwh

recorded go down

– Does not affect demand KW

– Multiple ways to determine

the meter is a net meter

Normal Operations

Customer Utility

Meter

Customer

Supply

Panel

Net Meter

Building

Load

At night, the Utility grid

provides power.

Utility and PV System

share load requirement.

PV System

provides power.

Export Import

Readings going Slowly Up

Backwards

Emergency Operations

Customer Utility

Meter

Customer

Supply

Panel

Building

Load

Utility fault causes loss of

power to the customer.

Utility and PV System

sharing load requirement.

PV System shuts

down without grid

reference signal.

X

Permanent Repair

Customer Utility

Meter

Customer

Supply

Panel

Building

Load

Permanent repairs made

to the service lateral.

PV System slowly ramps

up to full power.

PV System waits 5

minutes, then starts

generating again.

X

Temporary Repairs – Bridge Adapter

Customer Utility

Meter

Customer

Supply

Panel

Building

Load

Side-off repaired temporarily

with Bridge Adapter.

Customer not receiving

any benefit from their

investment in solar energy.

Without a phase-phase

voltage difference, PV

system cannot start up.

X

Temporary Repairs - PhazeSaver

Customer Utility

Meter

Customer

Supply

Panel

Building

Load

Side-off repaired temporarily

with PhazeSaver device.

Open PV System Breaker

or Disconnect to prevent

back feed to PhazeSaver.

A phase-phase voltage

difference now exists,

PV system will start up.

X

Keeping Information Up-To-Date

Breaker/Disconnect Location

• Must be shown on the One-Line Diagram which must be

posted near the meter to which the PV is connected.

Breaker/Disconnect Location

• If Breaker/Disconnect is

not within 10 feet of the

meter, the customer

must have signage

indicating their location.

Other Specifications Governing Solar

• EO-2115 – Handbook of General Requirements for

Electrical Service to Dispersed Generation Customers

• MEP-183 – Guidelines for Installation and Removal of

Temporary Bridging Adapters

• B-258 - Use of PhazeSavers and Servisavers at Locations

with Distributed Generation

Distributed Generation

Safe Work Procedures

Griffin Reilly

Section Manager

Targeted Demand Management

Energy Efficiency and Demand Management

Consolidated Edison Company of New York, Inc.