By Laura Christensen, NERC Reliability Specialist
Perhaps you’ve heard the news or maybe you’re hearing it for the first time now. Solar GADS opens soon with a 3-year implementation. In year 1 there will be voluntary reporting for Q3 and Q4 of 2023. In year 2 (2024), solar plants with an aggregate greater than or equal to 100 MW will be required to report GADS data. Following the next year, year 3, solar plants with an aggregate greater than or equal to 20 MWs will be required to report GADS Data. Plants that don’t meet the required reporting criteria may still report on a voluntary basis.
There are three types of data files that will be reported: Configuration, Monthly Performance, and Event data. Under the configuration data there will be three different subcategories to report on. These are plant information, inverter group data, and energy storage group data. If you’re not sure what inverter group data or energy storage group data are, there’s a link to the NERC report that goes into more detail attached to the end of this article. There will be specific formatting requirements for the data. The excel-format templates will be available soon on NERC’s website.
For plant data, “plant” has been described as a collection of inverter groups at a single physical location managed by a single manager and operating out of a common Operations and Management building. There could be multiple inverter groups and the site may or may not have connected energy storage. The plant will have a unique ID assigned by NERC through the GADS solar reporting application. Now you might be asking, what is an inverter group and energy storage group as they have been mentioned a few times. An inverter group, which there can be more than one group at a plant, is a collection of solar inverters with the same manufacturer, design, system capability, model number, and phase of construction. Each inverter group will have a unique ID assigned to the plant. As for Energy Storage Groups, this is a collection of energy storage equipment of the same technology, manufacturer, design, system capacity, model number, and phase of construction that is electrically connected to a renewable energy generating plant and installed on-site. Each energy group will also have a unique ID.
Now you might be asking, when do I start reporting data? If you’re a new facility, it will be required after the first full month after COD, acquisition, or repowering. For existing plants, the first time you submit data, you’ll be required to provide the configuration data. This should be reviewed quarterly and updated as changes occur. The plant configuration data for Solar has a few differences to it from the already established GADS reporting. Some of these differences are elevation, solar regime environment, global horizontal irradiance (insolation), Inter-Annual Variance of GHI, and the on-site connected energy storage. The inverter group and energy storage group configuration data will be required in the same manner as the plant configuration data. These are new to GADS.
Performance data, like other GADS reporting, will be due quarterly within 45 days of the end of the quarter. Monthly performance data will be recorded beginning the third full month after COD, acquisition, or repowering. Any reportable event, regardless of whether monthly performance data has begun, will be required to be reported. Performance data is required for the facility, inverter group(s), and energy storage group(s).
The last section of GADS reporting is Event Reporting. An event is characterized by a decrease in actual generation of at least 20 MW below the expected generation. For the event to end, the expected and actual generation must be less than 5% and the plant is producing 10% of the Plant Total Capacity or 5MW of energy, whichever is greater or 95% of the nameplate capacity of the equipment unavailable to the event cause has been returned to service. Just like with other GADS reporting, there will be event codes to operating conditions that caused the event.
The last reporting criteria is the Potential Production MWH Loss. This is the difference between the Actual Generation curve and the Expected Generation curve during the event period. The MW loss during an interval is then multiplied by the duration of the interval.