Monthly Archives: July 2019

How to download legacy electricity market data from SEM-O

The Irish Single Electricity Market Operator’s website changed when the new I-SEM electricity market commenced in 2018. However, it is still possible to download historic data from the pre-2018 SEM. A previous post discussed how to obtain the output of individual generator units on the SEM. This post describes how to download historic market information. This includes wind forecasts, wind generation, generator outputs and prices. Here, the instructions to download market prices are given.

Go to the legacy SEM-O page:

Sign in.


Market Data > Dynamic Reports

Report Type  : Dynamic Reporting – Tables

Report Group : All

Report: Market Results (System Load SMP and Shadow Price)

In the following screen, choose run ‘EA2’ (ex-Ante run 2)

From : date in mm/dd/yyyy To: mm/dd/yyyy

Click ‘popout report’

  • The report can be downloaded in CSV form and viewed in a text editor or Microsoft Excel.

The data can be interpreted as follows:

SMP is the ‘system marginal price’ in Euro cent. The data is presented on half hourly intervals. Each ‘Delivery Hour’ has two ‘delivery intervals’. Delivery interval 1 for hour X runs from X:00 to X:30 and delivery interval 2 runs from X:30 to [X+1:00].


You can download the list of SEMO generator units from here (if the SEMO link is broken ) :