Short Term Adequacy

Purpose

In every moment there must be balance between the generation and consumption of energy. This means that electricity must be generated at the exact moment when it is needed, this is due to the lack of storage facilities for electricity. To secure the supply of energy there is a need to investigate if the reliable available capacity can meet the consumption at any given time, while also taking into account that there might be restrictions in the transportation of electricity to the place of consumption. If there is not enough reliable available capacity to meet the consumption, measures need to be taken to avoid an adequacy situation.

The STA performs the analysis if there is sufficient reliable available capacity to meet the consumption, given the capacity constraints in the grid. This assessment is done daily for the W-1 time frame and provides the TSOs with a STA forecast.

 

Methodology

The STA service is described in (SOGL ) article 81 – Regional Adequacy Assessment, and there it is laid out which input data that should be used and the responsibilities of the TSOs and the RSCs. It is also described that RSCs should propose remedial actions for the TSOs in case an adequacy situation is discovered.

The regulations described in SOGL, gives room for performing the STA analysis in different ways.

The Nordic RSC together with the Nordic TSOs have developed a methodology where the Nordic TSOs’ input data (load, reliable available capacity and transmission capacity) is represented in graphs to provide an overview  of the adequacy situation in the Nordics.

On a European level, a methodology to perform an adequacy assessment for the whole of Europe has been developed. In this assessment all European TSOs provide input data to the calculations that result in an overview of the adequacy situation in Europe.

 

Step wise implementation

The Nordic RSC together with the Nordic TSOs have decided on a step wise implementation for the Nordic STA service.

  • NOA (Nordic overview of adequacy) platform – a user friendly platform that provides an overview of the adequacy situation in the Nordics
  • Calculation engine on NOA platform – adequacy flow calculations using PTDFs, with results represented in a Nordic map

For the European STA the coming steps are:

  • Further evolution of the cross – regional (CR) STA tool, which will include HVDC and generation tripping and must run
  • Implement a regional STA process, including all TSOs and RSCs

 

Video

See the video below for a basic explanation of the service provided by ENTSO-E and Coreso.