Capacity Adequacy Indicator

Capacity Adequacy Indicator

The Capacity Adequacy Indicator is a method of assessing the ability of available generation to meet the predicted system demand.

We publish the results for capacity adequacy each Thursday.  These results contain the prediction for the following four weeks, commencing the following Sunday.  It is updated each Monday.

Below this table is a brief explanation of the results provided.

Capacity Adequacy Indicator

Expected CDGU & Interconnector Availability

This is calculated as the sum of all Centrally Dispatched Generation Units (CDGUs) and the interconnector with Northern Ireland Electricity (NIE) that are expected to be available for a given peak, if the Forced Outage Probability (FOP) of all CDGUs and the interconnector = 0%.

Expected Daily Peak Demand

The Expected Daily Peak Demand displayed here represents the electricity production at the peak that is required to meet the national electrical consumption, including system losses and generators' requirements.  It includes consumption met by power imported via the interconnector, but excludes consumption met by some of the non-centrally monitored generation.

Expected Reserve at Peak

This is calculated as the difference between the "Expected CDGU & Interconnector Availability" and the "Expected Daily Peak Demand".  It should be noted that this reserve must be sufficient to cover any Forced Outages that may occur on the system, so as to ensure that the adequacy standards are not breached.

Expected Loss of Load Hours (LOLH) for the Committed Outage Program

This is the loss of load hours expected and is an indication of the likely duration over which the system demand may not be met.  The Generation Adequacy Standard is eight hours LOLH per year, which equates to 0.022 hours per day on average if the risk is evenly distributed over the year.

Centrally Dispatched Generation Unit (CDGU)

This refers to a Generation Unit that is normally subject to EirGrid's Dispatch Instructions.

Forced Outage Probability (FOP)

This is the forced outage probability - the probability, in percentage terms, that a generation unit will not be able to provide Energy or Ancillary Services.

Committed Outage Program

This is a program of outages of the Generator's power plant, prepared by EirGrid.