Generator Facility

Rating Methodology

Revisions

Rev.
No.
Date
Description
By
Approval
0 6/22/05 New Document JAZ FRO
1 2/22/07 Rev. for FAC-008-1 – Facility Ratings
Revised generation capability rating methodology to distinguish between commitment and long-term ratings.
Added reactive power capability methodology. JAZ FRO
2 9/29/2008 Rev. to reflect requirements of NERC FAC-008-1 and FAC-009-1. Added specific language to address nuclear units and jointly owned facilities outside FPL’s metered boundaries. Added language specific to communication of ratings. JAZ FRO
3 10/06/09 Added language specific for solar photovoltaic variable generation resource assets. Removed references to Capability Letter. Added statements regarding boundary of generator Facility. Added comments regarding the FAC-009-1, R1 requirement to establish generator Facility ratings per the Generator Facility Rating Methodology. JMG FRO Generator Facility Rating Methodology

The purpose of this procedure is to document the methodologies used by FPL (generator owner) in rating its generator facilities to meet the requirements of NERC Standards FAC-008-1, FAC-009-1. This procedure is applicable to fossil, solar photovoltaic and nuclear generator Facilities.

TERMINOLOGY

Bulk Electric System (BES): As defined by the NERC Regional Reliability Organization (RRO), the electrical generation resources, transmission lines, interconnections with neighboring systems, and associated equipment, generally operated at voltages of 100 kV or higher. Radial transmission facilities serving only load with one transmission source are generally not included in this definition.

Equipment Rating: The maximum and minimum voltage, current, frequency, real and reactive power flows on individual equipment under steady state, short-circuit and transient conditions, as permitted or assigned by the equipment owner.

Emergency Rating: The rating as defined by the equipment owner that specifies the level of electrical loading or output, usually expressed in megawatts (MW) or MVar or other appropriate units, that a system, facility, or element can support, produce, or withstand for a finite period. The rating assumes acceptable loss of equipment life or other physical or safety limitations for the equipment involved.

Facility: A set of electrical equipment that operates as a single BES Element (e.g., a line, a generator, a shunt compensator, transformer, etc.).

Facility Rating: The maximum or minimum voltage, current, frequency, or real or reactive power flow through a facility that does not violate the applicable Equipment Rating of any equipment comprising the Facility.

Generator Owner: Entity that owns and maintains generating units. Generator Owner refers to FPL in this document.

Variable Generation Resource Asset: A Variable Generation Resource Asset is a source of electric power generation that has a fuel resource that cannot be controlled or stored, and therefore is non-dispatchable, and is usually used to refer to some sources of renewable energy, such as wind and solar.

Normal Rating: The rating as defined by the equipment owner that specifies the level of electrical loading, usually expressed in megawatts (MW) or other appropriate units that a system, facility, or element can support or withstand through the daily demand cycles without loss of equipment life.

Off Control Continuous Capability (OffCC): The maximum net generation that can be obtained from a unit and sustained indefinitely without operating difficulties. For non-intermittent generating assets, OffCC varies with ambient conditions, and is equivalent to Normal Rating. For intermittent generating assets, such as solar PV, the OffCC is the average of the monthly site maximum expected generation for the season. The OffCC varies with ambient conditions and solar irradiance.

Peak Capability: The maximum hourly generation which, after advanced notice to the plant, can be maintained for periods of up to four hours, or longer with local management approval. Peak capability is equivalent to Emergency Rating. For intermittent generating assets, such as solar PV, the Peak Capability is the site maximum expected generation for the season. The Peak Capability varies with ambient conditions and solar irradiance.

Photovoltaic (PV) Site: Collection of photovoltaic panels which convert solar energy to electrical energy directly as a single Generator Facility. This type of generation is a variable generation resource asset and is referred to as a PV site in this document.

Regional Reliability Organization (RRO): A NERC entity that ensures that a defined area of the Bulk Electric System is reliable, adequate and secure. FPL generating units report to FRCC.

GENERATOR FACILITY RATING METHODOLOGY

Each generator Facility Rating shall equal the most limiting applicable Equipment Rating of the individual equipment that comprises that generator Facility (NERC Standard FAC-008-1, R1.1). The scope of equipment addressed shall include, but not be limited to, generators, transmission conductors, and transformers, relay protective devices, terminal equipment, and series and shunt compensation devices (NERC Standard FAC-008-1, R1.2.1). The generator facility boundary is defined as the electrical equipment from the generator to the low side of the main GSU transformer. For PV sites, the generator Facility is from the PV solar panel to the low side of the main GSU transformer.

Real Power
The generator Facility’s real power rating is based on historical performance and is adjusted for seasonal affects (NERC Standard FAC-008-1, R1.3.3). If there is no historical performance data available, the generator Facility’s real power rating is based on unit commissioning data, design calculations, such as heat balance calculations or manufacturer’s guarantee value or equipment manufacturer’s ratings, such as nameplate rating (NERC Standard FAC-008-1, R1.3.1, R1.3.2).

The FPL generator Facility is rated at Off-Control Continuous (Normal), and Peak (Emergency) (NERC Standard FAC-008-1, R1.2.2).

For some of the FPL generator facilities, the Normal and Emergency ratings are the same (e.g. base loaded nuclear units) (NERC Standard FAC-008-1, R1.2.2). For variable generation resource assets, such as solar PV, the OffCC and Peak ratings are uncontrollably variable and therefore non-dispatchable (NERC Standard FAC-008-1, R1.3.4).

The seasonal rating for each unit differs by the effects of ambient conditions on the unit, such as ambient air temperature and circulating water temperature. For solar PV generating assets, the seasonal rating is affected by the anticipated solar irradiation, ambient air temperature and wind speed (NERC Standard FAC-008-1, R1.3.3).

Each generator facility rating must take into account any known limitations associated with ambient conditions or any other operating limitations, such as limitations due to the equipment cooling systems, shorted rotor turns, vibration limitations, or other limitations and shall include any other assumptions pertinent to the stated ratings (NERC Standard FAC-008-1, R1.3.3, R1.3.4, R1.3.5).

Reactive Power

Each generator Facility’s lagging reactive power ratings are based on the real power rating as applied to the design Estimated Generator Capability Curves and are corrected for the effects of ambient conditions (NERC Standard FAC-008-1, R1.3.3) according to the changes in the generator Facility’s real power output as stated above. The leading reactive power capability is based on the setting of the minimum excitation limiter unless there is a more limiting component or system requirement (NERC Standard FAC-008-1, R1.3.4). If historical performance data is available, the generator facility’s reactive power ratings are compared to historical performance for validation. If no historical performance data is available, the generator facility’s reactive power rating is compared to the equipment manufacturer’s ratings, such as nameplate rating for validation (NERC Standard FAC-008-1, R1.3.1, R1.3.2). For solar PV sites, the reactive capability is rated at the required power factor as required in the interconnection agreement.

Each generator Facility rating must take into account any known limitations associated with ambient conditions or any other operating limitations, such as limitations due to the equipment cooling systems, shorted rotor turns, vibration limitations, or other limitations and shall include any other assumptions pertinent to the stated ratings (NERC Standard FAC-008-1, R1.3.3, R1.3.4, R1.3.5).

JOINTLY OWNED GENERATOR FACILITIES
The jointly owned generator facilities at Scherer 4 and St Johns River Power Park are rated by the Generator Operator, Georgia Power and Jacksonville Electric Authority (JEA), respectively. Thus, for these units NERC Standards FAC-008-1 and FAC-009-1 compliance is handled by Georgia Power and JEA. Real and reactive power is not rated by FPL for these units since they are not connected and operated within FPL’s metered boundaries.

COMMUNICATION OF FACILITY RATINGS
The Generator Facility ratings shall be established per the Generator Facility Rating Methodology (NERC Standard FAC-009-1, R1) and provided to the associated Reliability Coordinator, Planning Coordinator, Transmissions Planner, and Transmission Operator as scheduled by such requesting entities (NERC Standard FAC-009-1, R2).

FACILITY RATING CHANGES
Any modification to existing facilities and re-ratings of existing facilities shall be communicated to the associated Reliability Coordinator, Planning Coordinator, Transmissions Planner, and Transmission Operator as scheduled by such requesting entities (NERC Standard FAC-009-1, R2).

REQUIRED RESPONSE TO INQUIRIES
FPL, as the Generator Owner, shall make its Facility Ratings Methodology available for inspection and technical review by those Reliability Coordinators, Transmissions Operators, Transmissions Planners and Planning Authorities that have responsibility for the area in which the associated facilities are located, within 15 business days of receipt of a request (NERC Standard FAC-008-1, R2).

If a Reliability Coordinator, Transmission Operator, Transmissions Planner, or Planning Authority provides written comments on its technical review of a Generator Owner’s Facility Ratings Methodology, FPL, as the Generator Owner, shall provide a written response to that commenting entity within 45 calendar days of receipt of those comments. The response shall indicate whether a change will be made to the Facility Ratings Methodology and, if no change will be made to that Facility Ratings Methodology, the reason why (NERC Standard FAC-008-1, R3).