I. Data Collection and Reporting

Data must be collected and analyzed to measure the effectiveness of maintenance programs and to assess the effect of generating asset performance on grid reliability. All reported change of unit state event data, as required by this program, shall have detailed log entries at the respective generating facilities describing the event.

The majority of generation owners in the Western Electricity Coordinating Council (WECC) providing energy to California currently participate in the North American Electric Reliability Council's (NERC) Generating Availability Data System Services (GADS). For the sake of consistency, the CPUC has selected a subset of NERC GADS data that is to be reported by participants, and the NERC GADS protocol for applying definitions of unit state, and unit state changes, as the standard for data to be reported directly to the CPUC on a real time basis as changes of unit states occur. The generation asset owners shall have the option of reporting directly to the CPUC or reporting to NERC GADS and authorize the CPUC access to the NERC GADS data on a unit specific basis. In addition, NERC GADS Performance Definitions and Equations were adopted for use. These definitions are based on the Institute of Electrical and Electronic Engineers (IEEE) Standard 762, "Definitions for Use in Reporting Electric Generating Unit Reliability, Availability, and Productivity."

A. Required Data Sets

The data set chosen for monthly reporting to the CPUC includes the information required to derive each factor in the CUF calculation:

1. Cause Code (if applicable) to the time and date for each change of unit state (Event)

2. The unit state code for unit state prior to the change

3. The unit state code for unit state after the change

4. Net Available Capacity in the new state

5. Net Dependable Capacity at the time of year

1. Unit States

Outage

An outage starts when the unit is either desynchronized from the grid or when it moves from one Unit State to another. The outage ends when the unit is synchronized to the grid or moves to another unit state. In the case of moving from one Unit State to another, the exact date and time that one outage ends will be the same as the next outage starts. The Unit State can only be changed if the first outage ends.

Planned Outage (PO) - An outage that is scheduled well in advance and is of a predetermined duration, lasts for several weeks, and occurs only once or twice a year. Turbine and boiler overhauls or inspections, testing, and nuclear refueling are typical Planned Outages

Maintenance Outage (MO) - An outage that can be deferred beyond the end of the next weekend, but requires that the unit be removed from service, another outage state, or Reserve Shutdown state before the next Planned Outage (PO). Characteristically, a MO can occur any time during the year, has a flexible start date, may or may not have a predetermined duration, and is usually much shorter than a PO. Note that IEEE standard 762 considers this an unplanned outage.

Scheduled Outage Extension (SE) - An extension of a Planned Outage (PO) or a Maintenance Outage (MO) beyond its estimated completion date. Use SE only in instances where the original scope of work requires more time to complete than originally scheduled. Do not use SE in those instances where unexpected problems or delays outside the scope of work are encountered which render the unit out of service beyond the estimated end date of the PO or MO. Report these delays as Unplanned (Forced) Outage-Immediate (U1). SE or U1 must start at the same time (month/day/hour/minute) that the PO or MO ended.

Startup Failure (SF) - An outage that results when a unit is unable to synchronize within a specified startup time following an outage or Reserve Shutdown. The startup period for each unit is determined by the operating utility. It is unique for each unit, and depends on the condition of the unit at the time of startup (hot, cold, standby, etc.). A startup period begins with the command to start and ends when the unit is synchronized. SF begins when the problem preventing the unit from synchronizing occurs. The SF ends when the unit is synchronized, another SF occurs, or the unit enters another permissible state.

Unplanned (Forced) Outage (U1) - An outage that requires removal of a unit from service, another Outage State, or a Reserve Shutdown state anytime prior to the end of the next weekend. [This is inclusive of NERC GADS Unplanned (Forced) Outage Codes U1, U2, and U3]

Derates

A derating exists whenever a unit is limited to some power level less than the unit's Net Maximum Capacity. Similar to outages, the general derating event classification is divided into distinct event types. A derating starts when the unit is not capable of reaching 100% capacity. The available capacity is based on the output capability of the unit and not on dispatch requirements. The derating ends when the equipment that caused the derating is returned to service, whether the operators use it at that time or not. More than one derate can occur at one time. Report all deratings that are greater than 2% of the unit's Net Maximum Capacity and longer than 30 minutes in duration.

Planned Derating (PD) - A derating that is scheduled well in advance and is of a predetermined duration. Periodic deratings for tests, such as weekly turbine valve tests, should not be reported as PD's. Report deratings of these types as Maintenance Deratings (D4).

Maintenance Derating (D4) - A derating that can be deferred beyond the end of the next weekend but requires a reduction in capacity before the next Planned Outage (PO). A D4 can have a flexible start date and may or may not have a predetermined duration.

Derating Extension (DE) - An extension of a Planned Derating (PD) or a Maintenance Derating (D4) beyond its estimated completion date. Use a DE only in instances where the original scope of work requires more time to complete than originally scheduled. Do not use a DE in those instances where unexpected problems or delays outside the scope of work are encountered which render the unit incapable of full load beyond the estimated end date of the PD or D4. The DE must start at the same time (month/day/hour/minute) that the PD or D4 ended.

Unplanned (Forced) Derating (D1) - Immediate - A derating that requires a derating that cannot be delayed beyond the end of the next weekend. [This is inclusive of NERC GADS Unplanned (Forced) Derate Codes D1, D2, and D3]

Service

In-Service (IS) - When the unit is synchronized to the system.

Reserve Shutdown (RS) - The unit is available to the system but not synchronized for economy reasons.

Pumping Service (PS) - The unit is available to system, with or without, derates, but used in pumping capacity.

Available (A) - The unit is in a condition that allows it to be started up and synchronized to the grid (Reserve Shutdown), be used as a pump, or is actually synchronized to the system as generator or be used as a synchronous condenser (In-service).

Figure 1 illustrates the logical relationship between the defined Unit States possible for an active or inactive Generating Asset.

It should be noted that this protocol does not differentiate between a unit Available in the Reserve Shutdown status that is bid into the market or a unit in Available in the Reserve Shutdown status that is not bid into the market. Likewise, it doesn't differentiate between in-service with a bid less than full capacity. This was done deliberately, since bid status of a unit is not related to the effectiveness of the maintenance program, but a business or contractual decision.

2. Cause Codes

Outage and derate causes will be reported at the major system/sub-system level using NERC GADS cause codes. The NERC GADS Data Reporting Instructions contain a listing of cause codes.

When reporting an event, select the code, which best describes the cause or component responsible for the event. The following guidance should be used in selecting the cause code:

Assign the cause of the event to the major component or system that was responsible for the event, not to an auxiliary component or operation that triggered the failure of a major component or system. For instance, on a fossil steam boiler, failure of an air line to one feedwater regulating valve may cause closure of that valve, resulting in a boiler trip on low level. In this case, the cause code for the feedwater system would be chosen as the primary cause, not the code for the service air system. Conversely, if the feedwater regulating valve had failed as the result of a complete loss of service air system, the cause code would be assigned to service air (Balance of Plant Auxiliary Systems).

Report power supplies (motor control centers, breakers, etc.) which serve a particular component or system in the same manner, e.g. if a breaker for the boiler feedwater pump fails, the cause code would be assigned to the Feedwater System. Likewise, if the loss of power to the feedwater pump was due to a failure in the AC Distribution system that caused a loss of power to a number of systems or components, the cause code would be assigned to the Electrical System.

Report instruments or controls for a component (such as pressure switch, pressure regulator, position indicator, etc.), which are a part of a fan, pump, or valve as the system for the component. The exception is for instruments or controls that are components in a designated system, such as Boiler Control. Report all instruments, transmitters, logic modules, etc. for these systems using the System Code for that control system.

Use the codes for "External" and "Safety, Regulatory, and Environmental" only when no other system/component cause code applies. For instance, if stack emission limits are exceeded because of a fault in the flue gas scrubber, use a scrubber code. However, if a new limit on emissions is imposed and is exceeded even though the scrubber is functioning properly, then use an environmental code.

The Primary Cause of event is required for all outages, startup failures and derates. Cause codes are not required for a change of Unit State related to Service, e.g., Reserve Shutdown, In Service, Pumping, or Synchronous Condensing.

FIGURE 1

B. Data Reporting

The data to be provided is divided into three different categories, design, event, and performance. This section is subdivided by data type, and provides explanation of how each type of data is to be reported. Section (1) describes the design data to be reported and required transmittal specifications. Section (2) details the event and performance reporting requirements.

1. Design Data

Design data is fundamental data necessary for NERC GADS to classify the generating asset and develop the appropriate data base code tables for that asset. Generating asset owners shall either report design data to NERC GADS, and authorize the CPUC access to such data on a unit specific basis, or provide such design data, in identical format, directly to the CPUC upon request. Normally, design data must be reported to NERC GADS when the unit first enters the active state. This is termed the "service date" and occurs when the unit is first declared available for the dispatch of power at some level of its capability. If, at the issuance of this document, the design data for a generating asset has not previously been reported to NERC GADS by the present, or prior owner, the design data will be reported to NERC GADS or to the CPUC within 30 days following the announcement of the Generation Maintenance Program implementation. While a discussion of the design data is presented here, see GADS Data Reporting Instructions for specific instructions and complete description of data. The minimum design data includes:

Unit Type

· Nuclear (steam) units - those units consisting of a single reactor and a single turbine-generator. In cases where multiple reactors or multiple turbine-generators are headered together, the entire ensemble is considered a single unit.

· Fossil (steam) units - those units consisting of a single boiler and a single turbine-generator. In cases where multiple boilers and/or multiple turbine-generators are headered together, the entire ensemble is considered a single unit.

· Hydro, pumped storage, gas turbine, jet engine, and diesel units - those units consisting of the unique prime mover and a single generator. In cases where multiple combinations of turbines/engines and generators exist, either physically or because of operating philosophy, the entire ensemble may be considered as a single unit or as individual units.

· Combined cycle units - those units consisting of one or more gas turbines/jet engines and one or more heat recovery boilers. The steam from the heat recovery boiler is sent to a steam turbine for generating electricity. Units where the gas turbines/jet engines can generate independent of the heat recovery boilers and steam turbine are also combined cycle units. The entire ensemble is considered a single unit.

· Cogeneration units - those units consisting of one or more gas turbines/jet engines and one or more heat recovery boilers. The steam from the heat recovery boiler is used for other purposes (process steam), not generating electricity. The entire ensemble is considered a single unit.

· Fluidized bed combustion units - those units consist of one or more bubbling, circulating or pressurized bed boilers or steam turbines. Consider the entire group as a single unit.

Unit Capacity - Gross: Gross Maximum Capacity (GMC) - The maximum capacity the unit can sustain over a specified period of time when not restricted by ambient conditions or deratings. To establish this capacity, formal demonstration is required. No standard demonstration test method or test duration exists at this time. The GMC of a unit should change only as a result of a new performance test or permanent unit modification. GMC is never changed due to equipment problems, even if they persist for a lengthy period of time unless the unit is permanently modified as a result.

Unit Capacity - Net: Net Maximum Capacity (NMC) - NMC is the unit's GMC less any capacity (MW) utilized for that unit's station service or auxiliary load.

Gross Dependable Capacity (GDC) - The gross power level that the unit can sustain during a given period if there are no equipment, operating, or regulatory restrictions. By definition, therefore, the GDC is the GMC modified for ambient limitations. The GDC is the same in intent and purpose as the historically reported Maximum Dependable Capacity (MDC).

2. Event and Performance Data

An "event" occurs any time a generating unit changes Unit State as defined in Data Set above. This typically includes a change in operating status or changes in capability. Reporting event data and performance data, provides all the information needed to evaluate generating unit availability and capability performance.

Event data (changes in unit state) will be reported to the CPUC andmonthly performance summaries reported to NERC GADS or the CPUC quarterly. Figure 2 depicts the general requirement of data. Monthly reports shall include all Unit State changes, which have occurred since the end of the last reporting period. The quarterly report to NERC GADS or the CPUC is a summarization of operations for the reporting period.

Performance Data associated with the event reporting to the CPUC is limited to:

Net Dependable Capacity (NDC) - Is the Net Maximum Capacity less the Seasonal Derate due to environmental impact, if any.

Net Available Capacity (NAC) - Is the current limit on Net Capacity, regardless of whether it is bid in, or demanded.

Figure 2 - Example Event Report

Generating Facility ID
Report Period	From:			To:
Change of Unit State (Examples)	Date (mm/dd)	Time (24 hour clock)	From Code	To Code	Cause Code	Net Available Capacity	Net Dependable Capacity
Planned Derate - Feedwater System from full power (350 MW to 75% of full power) occurring at 1230 am, July 28 and lasting till 2330 on July 29.	7/28	0:30	IS	PD	3400*	262.5	350
Return to full capacity	7/29	23:30	PD	IS	NA**	350	350

* Hypothetical cause code.

** No cause code required when changing into the In-Service, Reserve Shutdown or Pumping Service states.