Customer Services - Consumer Portal - Net Metering with DER Function

Narrative
Steps
Additional Information

Narrative

Overview

A utility company wants to effectively use the DER System Controllers (DER) installed in customer sites to reduce its contract power purchase during peak load periods. These customers have signed up for net-metering and agreed to meet specified Power Quality (PQ) criteria. The utility would use its internal demand projection models and communications with the DER, along with guaranteed buy-back of power agreements, to implement economic peak rate power purchase under its contract power purchase agreements.

Description

A western utility has a residential customer base of 1 million meters. The meters are installed in single-family detached housing (SFD), single-family attached housing (SFA), apartment buildings, and mobile homes. The utility wishes to promote the use of renewable resources within its residential and light commercial client base.

The utility decides to provide incentives for the residential and light commercial use of DER System Controllers (DER) by offering a guaranteed buy-back of power under specific conditions. The plan requires the customers to install DER with their own resources and the utility will purchase power delivered to the grid (specified in DER regulations) during periods of high demand.

A specific subset (100 total) of the customers participating in the DER program resides on a congested T & D feeder in a specific geographic area of the service territory. Thus it’s advantageous for the utility to “involve” these customers during times of peak demand or high purchase power contractual periods.

The issues confronting the utility during seasonal high demand periods are:

· They need to know which homes of the 100 have DER installed, the size of the DER (kW) and the type of DER (solar PV, generator, etc).

· They need to know which customers have signed net-metering contracts.

The utility enters into a typical high demand period; ambient temperatures are rising and HVAC loads are increasing. The utility desires to call up DER. and goes through the following procedures:

The utility interrogates primary line meters on the T & D feeder and starts to continuously monitor line loading. The utility has developed a model to assess the primary Meter Device load ramp and can predict when the feeder will become overloaded at the monitored rate-of-change. The model predicts that at the present rate of change the line will become critical within one hour.
Based on this fact, the utility calls up an internal database for that specific geographic area and determines which customers have DER and how much power (kW) they have. Based on the database results, the utility interrogates the customer portals to assess which units are already on line and which ones are available to be called up (available units must provide an “availability” signal as part of their contract with the utility).
The utility notifies the customers that specific DER units will be called up within 30 minutes. The DER is brought on line at a specific time and the contractual buy-back rate goes into effect (the rate is guaranteed at 90% of purchase power at that time period, with the 10% differential going into system O & M). Thus the utility is now buying DER power at 90% of a purchase power rate that is determined by calling up the utility’s purchase power contracts interactive spot-power database.
The utility Power Quality group examines each customer’s DER to insure that the output is within the contractual standards for Power Quality. Units not complying are dropped from the line within 500 milliseconds and a notation is made as to why the unit(s) was dropped.
The remaining customers’ net-meters are now supplying the utility enterprise with delivered power for a prescribed time that must be credited to the customers’ accounts and eventually show up on their monthly invoice as a credit.
The utility determines that the peak demand problem has been averted and does not elect to purchase expensive power under contract.
The billing department now calculates the amount of money to reimburse each DER participating customer based on agreed upon rates [see Step 3 above] and for the measured time period.
The Power Quality department notifies the DER customers that failed PQ monitoring, the reason why and requests repairs to permit continued participation in the net-metering/DER program.

Steps

#	Event	Name of Process/Activity	Description of Process/Activity	Information Producer	Information Receiver	Name of Info Exchanged	IntelliGrid Architecture Environments
1.1	T & D Feeder Line Meter Device Query	Check feeder overload projection	DER system receives ambient temperature, demand data and HVAC load data	Utility T & D data	DER System Controller	Ambient temperature and load data exceeding specified threshold values	DER Monitoring and Control
1.2		DER system queries	DER system queries utility’s load prediction model	DER System Controller	Load Prediction Model	System data for use by the model	DER Monitoring and Control
1.3		Identifies feeder line risk	Load prediction model identifies feeder line at risk of overload event	Load Prediction Model	DER System Controller	Information identifying feeder at risk	DER Monitoring and Control
1.4		Activation trigger for DER program activities	DER system generates trigger to activate DER program for the identified feeder line	DER System Controller	DER Database	Activation trigger for DER program activities	DER Monitoring and Control
2	DER Activation Order	Find Amount and types of power that can be obtained from the customers participating in the DER program	DER system queries DER database to determine power capacity from customers in the affected segment	DER System Controller , T & D system, DER Database	DER System Controller	Amount and types of power that can be obtained from the customers participating in the DER program	DER Monitoring and Control
2.1.1		Actual available power from the targeted DER customers	DER system signals identified customers to determine availability	DER System Controller , Customer Communication Portal, DER System Controller	DER System Controller	Actual available power from the targeted customers	DER Monitoring and Control
2.1.2	DER systems signals to check for availability	Activation alert to customers on pending program activation	DER system alerts customers with available power on system activation in 30 minutes	DER System Controller	Customer Communication Portal, DER System Controller	Activation alert to customers on pending program activation	DER Monitoring and Control
2.2		Signal to turn on DER equipment at available customer sites	DER system turns on DER equipment at targeted customers’ sites	DER System Controller	Customer Communication Portal, DER System Controller	Signal to turn on DER equipment at available customer sites	DER Monitoring and Control
2.3		Activate PQ monitoring system	Activates PQ monitoring of delivered power	PQ Monitoring System	DER System Controller	PQ data on delivered power	DER Monitoring and Control
2.3.1	DER equipment failing	Turn-off DER equipment	Turn off DER equipment failing PQ criteria	DER System Controller	DER System Controller , Customer Communication Portal	Signal to failing units to turn off	DER Monitoring and Control
2.3.1.1		Flag PQ failing DER	Flag failing units for follow-up remedial actions	DER System Controller	DER Database	List of DER System Controller units failing PQ criteria	DER Monitoring and Control
2.4		Record energy delivered to the grid	Alert Customer Communication Portal at conforming DER customers to record power delivery	DER System Controller	Customer Communication Portal, Customer Net-Metering Device -Meter Device	Information on amount of power and duration of power delivered to the grid	DER Monitoring and Control
2.5		Delay buying power on spot-market	Signal Purchasing Selling Entity to delay spot-market power purchase	DER System Controller	Purchasing Selling Entity	Delay buying decision for power purchase on spot-market	DER Monitoring and Control
2.6		Determine contract power buy-back rate	2.6 Query utility’s spot-market power database to determine contract power rate	Purchase Power Contracts Interactive Spot-Power Database -	DER System Controller , DER Database, Customer Billing System	Power buy-back rate applicable to power from DER System Controller to utility grid	DER Monitoring and Control
2.7		On-going tracking feeder overload	On-going tracking feeder overload condition and load prediction model	Load Prediction Model , T & D	DER System Controller	Status data indicating the need for DER power from customers	DER Monitoring and Control
3.1	Monitor T&D data	Predict if DER program and DRP can be terminated	Load Prediction Model and T &D data indicate DER activation can be terminated	Load Prediction Model , T & D	DER System Controller	Trigger to initiate DER event termination	DER Monitoring and Control
3.2	DER program and DRP can be terminated	DER System Controller initiates termination sequencing	DER System Controller initiates orderly sequencing DER program termination	DER System Controller , DER Database	Customer Communication Portal, DER System Controller	Message to DER System Controller unit on shutdown schedule	DER Monitoring and Control
3.2.1		Transmit DER turn-off signal	Transmit DER turn-off signal to each customer as per the schedule	DER System Controller	Customer Communication Portal, DER System Controller	Signal to individual DER unit to terminate power delivery	DER Monitoring and Control
3.2.2	Transmit DER turn-off signal	Confirmation of power delivery turn-off	Confirmation by customer unit of power delivery termination	Customer Communication Portal, DER System Controller	DER System Controller	Positive acknowledgment of system turn-off	DER Monitoring and Control
3.3		Power delivered during DER event	Customer site transmits net power delivery during DER event	Customer Communication Portal, Customer Net-Metering Device -Meter Device	DER Database	Details of amount of power delivered, duration of power delivered during the DER event	DER Monitoring and Control
3.3.1		Generate power delivery and rate information	Delivered power information and applicable rate data sent to billing system	DER System Controller , DER Database	Customer Billing System	Amount and details of credit to be issued to customer for power delivered during the DER event	DER Monitoring and Control
3.3.2		Amount of power purchase avoided due to DER program	Delivered power by customer DER units and peak load averted data to Purchasing Selling Entity	DER Database	Purchasing Selling Entity	Amount of power purchase avoided due to DER program activation	DER Monitoring and Control
3.3.3		Signal no additional DER power to be purchased	Signal Purchasing Selling Entity that no additional power needs to be purchased	DER System Controller	Purchasing Selling Entity	Finalize decision not to purchase power in spot-power market	DER Monitoring and Control
3.4		Retrieve list of failed DER units	Retrieve list of customer DER units that failed PQ criteria	DER Database	DER System Controller	List of customers requiring follow-up actions	DER Monitoring and Control
3.4.1	DER units failed PQ criteria	Alert customer on PQ failure	Alert these customers on PQ failure details	DER Database	Customer Communication Portal	Details of PQ failure during DER event	DER Monitoring and Control
3.4.2	DER units failed PQ criteria fixed	Request PQ capability compliance confirmation	Request these customers to alert DER System Controller on bringing their system into compliance	DER Database	Customer Communication Portal	Alert affected customers on need for remedial actions	DER Monitoring and Control
3.4.3		Flag affected customer sites	Flag the affected customer sites for future event till compliance confirmation is received	DER System Controller	DER Database	Flag the affected customers to indicate compliance confirmation is needed before they can be considered for program participation during future DER events	DER Monitoring and Control

Additional Information

Actor (Stakeholder) Roles

*Grouping (Community) ^,*		*Group Description*
*Customer Site*		*Those entities that are located at customer’s premises*
*Actor Name*	*Actor Type (person, device, system etc.)*	*Actor Description*
Customer	Person	One signed up to participate in the DER System Controller (DER) program.
Customer Communication Portal	System	System handling communications function at customer’s premises [in this case, communications with the installed DER, net-Meter Device , power quality system and the utility’s DER operations]
Net-Metering Device -Meter Device	Device	Device that can measure and transmit the net flow of power to the customer [i.e., it measures power flow in both directions – into the customer premises from the utility and out to the utility from customer premises – and generates a net Meter Device data that can be used by the utility to bill the customer accordingly]
DER System Controller	System	System at the customer site that generates power and is set up to be brought online at the demand of the utility company
Remote Meter Device	System	System for transmitting Meter Device data on demand to the utility.

*Grouping (Community) ^,*		*Group Description*
*Power Company DER System Controller Operations*		Those entities that are charged with managing the DER System Controller functions for the power company to optimize the loading of the Transmission & Distribution grid
*Actor Name*	*Actor Type (person, device, system etc.)*	*Actor Description*
DER System Controller	System	DER System Controller Center: System at the power company that handles DER operations [such as the system load model, decisions on when to initiate DER activities, triggering communications with other utility departments and the DER program participants, etc]
Line Meter Device	Device	Device that measures loading of feeder line in specific T & D grid sectors of the utility
Transmission & Distribution Feeder	System	System that handles the T & D function to specific geographic sector in utility’s service area.
DER Database	System	System that contains information about customers participating in the DER program, their location, details of their system (such as DER installed, the size of the DER (kW) and the type of DER (solar PV, generator, etc)), whether they have signed net-metering contract, and so on.
Customer Billing System	System	System that handles generation of bills for the services provided to the customer
PQ Monitoring System	System	Power Quality Monitoring System: System that monitors the operation and the power quality of the power generated by customer’s DER to qualify it for transmission on to utility’s grid
Purchase Power Contracts Interactive Spot-Power Database	System	System used by the utility to track and determine the spot price of power that it can purchase under its existing contracts
Load Prediction Model	System	System that a models feeder load by automatically tracking weather, load and other conditions to project overload events at specific feeder lines and connected to the DER database
Utility Communications Network	System	System responsible for managing communications between the utility and the participants in the DER program [for functions such as remote Meter Device reading, controlling DER units at customer sites, monitoring net-meters and other related communications activities]

*Grouping (Community) ^,*		*Group Description*
*Others*		*Those entities that are involved in this activity, but do not fit in any of the Groupings above*
*Actor Name*	*Actor Type (person, device, system etc.)*	*Actor Description*
Metering	Person	Department at the utility that manages meters and their installation at the customer site
Purchasing Selling Entity	Person	Department at the utility company that handles procurement of power resources for the utility company.
T & D	System	Transmission & Distribution (T & D) Grid : System at the utility company that manages the Transmission and Distribution grid for the utility company and monitors for loading factors, etc.
Utility Communications Network	System	System responsible for managing communications between the utility and the participants in the DER program [for functions such as remote Meter Device reading, controlling DER units at customer sites, monitoring net-meters and other related communications activities].
Energy Service Provider

Information exchanged

*Information Object Name*	*Information Object Description*
T & D Feeder Line Meter Device Query	Query from utility’s DER Center to T & D feeder line Meter Device to determine the potential for line overload and generating the trigger to activate the DER program in the affected segment
DER Activation Order	System order to initiate DER ahead of projected line overload, communications to the participating customers to alert the onset of DER, verifying DER availability at each customer site, bringing online selected DER at customer sites, monitoring the PQ at each site, alerting the Customer Communication Portal and net-Meter Device at each site to record delivered power and flagging the power delivered for appropriate payment by the billing system
DER Order Termination	System order to terminate the DER at the customer site based on model projection of averting peak demand problem, crediting each customer for power delivered as per applicable rates, decision on not purchasing power under contract from other sources and alerting customers whose DER failed to meet applicable PQ criteria

Activities/Services

*Activity/Service Name*	*Activities/Services Provided*
Determine Potential Feeder Peak Load Problem	Based on ambient temperatures and HVAC loads crossing the threshold values, trigger a query to utility feeder load model to determine if a specific feeder line will face overload problem; if the model predicts potential overload problem, trigger activation of DER activities for that sector
Initiate DER Program Activation	Initiate actions to activate DER program activities for the targeted feeder line: query DER database to flag DER customers in the affected segment, identify amount of power (kW) available from registered DER from customers in that segment, generate a query to those customers to determine their DER system availability and generate an alert to those with available DER system to indicate potential program activation within 30 minutes
Implement DER	Activate DER systems at customers already alerted and with available systems, alert the Customer Communication Portal and net-meters at those locations to record power delivered and duration of power delivery, activate PQ monitoring of delivered power to verify compliance with system requirements, drop non-complying units from the grid and flag for notice after the event, track feeder load to determine timing for program termination and hold-off contract power purchase on spot market during the DER program period
Terminate DER	On indication by the power model of the end of the projected overload problem for the feeder line, send out a trigger to customer DER systems supplying power to terminate operation, record power supplied and duration of power supply, finalize decision not to buy power under spot-market purchase contract and revert system back to monitoring mode for next overload situation
Complete Post-DER Activities	Initiate actions to transmit net-metering data to billing to generate credit to customers for the power supplied at the contractual buy-back rate, generate an alert to customers whose DER systems failed to meet prescribed PQ criteria and notify all customers in the DER program that the current DER event has been successfully terminated

Contracts/Regulations

*Contract/Regulation*	*Impact of Contract/Regulation on Function*
DER Program Tariffs	Specifications of DER equipment installed at customer site, net-metering equipment at customer site, contractual buy-back rates, PQ acceptance criteria and power supply credits applied to customer bill

*Policy*	*From Actor*	*May*	*Shall Not*	*Shall*	*Description (verb)*	*To Actor*
Install DER Equipment	Customer			X	Customer needs to install DER system at site to participate in the program	Energy Service Provider
Install Net-Metering Device -Meter	Energy Service Provider			X	Install specified net-metering equipment at customer site	Customer
Activate DER	Energy Service Provider	X			Activate and bring online customer’s DER	Customer
Meet PQ Criteria	Customer			X	Customer shall maintain the DER system in a manner that will ensure that the DER meets specified PQ criteria for power delivery	Energy Service Provider
Buy-back Power During DER Event	Energy Service Provider			X	Utility shall buy-back power at contract rates from customer’s DER during a DER event if the customer’s delivered power meets PQ criteria	Customer

*Constraint*	*Type*	*Description*	*Applies to*
Program Participation	System Availability	A customer can participate in a given DER event only if the DER system is in “available” state	Selecting customer for DER participation
Power Delivery	PQ	Customer’s DER unit to meet specified PQ criteria to be permitted to deliver power to the utility	Acceptance of power from customer’s DER and eligibility to continue participation in the program
Power Buy-back	Buy-back Rate	On DER program activation and customer DER meeting availability and PQ criteria, the utility is obligated to buy-back power at 90% purchased power rate at that time	Rate paid by the utility to customer for power delivered to the grid