In this blog we will discuss the NERC Solar DRI for 2024, and examine its impact on the solar energy sector. NERC guidelines and standards are key in shaping industry practices, particularly in renewables and solar.

Who is required to report?

All entities registered with NERC that have a Generator Owner role and manage solar generation facilities with a total installed capacity of 20 MW or more per plant, starting commercial operations on or after January 1, 2010, are obligated to report solar performance data, irrespective of their interconnection status.

The total installed capacity of a plant is determined by the cumulative capacity of its inverter groups, excluding any energy storage capacity.

The guidelines for reporting specify the data elements that must be submitted through the GADS Solar Reporting application, which the industry recognizes as essential for analyzing and comprehending the performance of solar power plants.

Part 1: Data Record Types and Format

1. Configuration Data:
   1. Plant
   2. Subgroup
   3. Energy Storage
2. Monthly Performance Data
   1. Inverter Group
   2. Energy Storage
3. Event Data
   1. Plant

Configuration data, essential for setting up asset reporting, must be submitted before performance and event data. It should be updated as necessary, with a quarterly review recommended.

Data submission to NERC utilizes Excel-format XML templates from NERC’s website, adhering to specific formatting rules. Reporting is quarterly, due within 45 days post-quarter, with late submissions requiring notification to regional contacts. 

Part 2: Plants, Inverter Groups, and Energy Storage Groups

The above figure illustrates a typical solar plant’s structure, highlighting the plant boundary at the revenue meter, where inverter groups can vary by development phase or connection type.

Plant boundaries are defined primarily at the revenue meter, with alternatives depending on inverter group arrangements or other logical demarcations, ensuring they do not extend across regional or national borders.

A plant comprises multiple inverter groups managed from a single location, with unique identifiers for each plant and inverter group.

Energy storage groups, also uniquely identified, consist of storage technology integrated within the plant’s boundary, sharing similar characteristics and connected to the renewable energy generation.

Part 3: Configuration Data

Configuration data, which includes details about a plant’s location, environmental conditions, and design, must be submitted before any performance, event, or outage data.

This initial submission assigns unique identifiers to the plant and its components, which are retained throughout its lifecycle. Updates to configuration data can be made at any time and should be reviewed annually to reflect any changes like retirements or ownership transfers.

It’s important that reported values align with those provided to other regulatory bodies. Configuration data is initially required in the month following a plant’s commercial operation, acquisition, or repowering.

Inverter Group Configuration

An Inverter Group consists of solar inverters sharing the same manufacturer, design, capacity, model, and construction phase. NERC assigns a unique ID to each group via the GADS Solar Reporting system. Every plant is required to have at least one Inverter Group documented.

Energy Storage Group Configuration

An Energy Storage Group consists of energy storage systems that share the same specifications, such as manufacturer, design, capacity, and model, grouped together. 

NERC assigns a unique identifier to each group for tracking within the GADS Solar Reporting application.

These groups are required to report their performance data monthly, focusing on the operations of energy storage systems connected on-site.

Part 4: Performance Reporting

Performance data, detailing operations of inverter and energy storage groups for a month, are vital for assessing performance, reliability, and availability.

This data must be reported quarterly within 45 days after a quarter ends.

Starting from the third month post-Commercial Operation Date (COD), acquisition, or repowering, monthly performance data collection is mandatory.

Any significant events post-COD need reporting even if monthly performance data collection hasn’t started.

Inverter Group Performance Record

Column	Field Name	Column	Field Name
1	Entity ID	15	Inactive Reserve Inverter Hours
2	Plant ID	16	Mothballed Inverter Hours
3	Inverter Group ID	17	Retired Unit Inverter Hours
4	Report Period (month)	18	Service Inverter Hours Day
5	Report Year	19	Reserve Shutdown Inverter Hours
6	Inverter Group Availability Status	20	Forced Outage Inverter Hours Day
7	Gross Actual Generation (GAG) (MWh)	21	Maintenance Inverter Hours Day
8	Net Actual Generation (NAG) (MWh)	22	Planned Inverter Hours Day
9	Net Maximum Capacity (NMC) (MW)	23	Resource Unavailable Inverter Hours – Day
10	Monthly Plane of Array (kwh/m2)	24	Service Inverter Hours Night
11	Performance Ratio	25	Forced Outage Inverter Hours Night
12	Expected Generation (MWh)	26	Maintenance Inverter Hours Night
13	Active Solar Inverter Hours	27	Planned Inverter Hours Night
14	Active Inverter Hours	28	Resource Unavailable Inverter Hours – Night

Data on the operations of Energy Storage Groups for a specific month is essential. Such performance data, mandatory for every energy storage group, captures their operational metrics during that period.

Part 5: Event Reporting

Event Detail reporting captures significant outages at the plant level, essential for grid impact assessments.

Events are marked from the known start to end times, adjusting for discovery delays, like overnight issues noticed at sunrise.

Reporting follows a quarterly schedule, within 45 days post-quarter, applicable to all plants including new or modified ones post-commercial operation.

Events qualify for reporting when a minimum of 20 MW capacity is lost due to forced outages, concluding when 95% of affected capacity is restored and less than 20 MW remains offline.

Plant Event Record Field

Column	Field Name
1	Entity ID
2	Plant ID
3	Event ID
4	Time Zone
5	Event Start Date/Time
6	Event End Date/Time
7	Event Type
8	Cause Code
9	Contributing Operating Condition
10	Description
11	Potential MWh Production Loss

Challenges and Solutions

Adopting the new guidelines will present obstacles, particularly for solar energy operators who may encounter technical and logistical issues during system upgrades to align with updated standards.

It is recommended that generators pursue as much automation in generating Event and Performance data as possible. This approach will minimize manual work and enhance accuracy and compliance, ensuring regulatory adherence while reducing the likelihood of penalties from inaccurately reported data.