STOR – Assessment principles

NGESO’s objective is to operate the transmission system economically, and the assessment is made consistent with that.

STOR is procured on a daily basis in an auction for contracts lasting one day. Providers submit their availability prices and MW offering prior to the day ahead auction, which is then cleared to secure firm capacity for STOR for lowest availability cost.

We consider the alternative costs for securing short term operating reserve closer to real time, and will compare all STOR bids against the economic costs of procuring the same volume of reserve from alternative sources.

A STOR bid will only be accepted where we consider that the total costs of securing and operating the system are lower with the bid, than without it.

For further details and examples of how the auction works, please see the STOR assessment principles below.

Related documents

These are useful documents with further details about the assessment process for STOR.