Calculating Great Britain's half-hourly electrical demand from publicly available data

Here we present a method to combine half-hourly publicly available electrical generation and interconnector operational data for Great Britain to create a timeseries that approximates its electrical demand. We term the calculated electrical demand ‘ESPENI’ that is an acronym for Elexon Sum Plus Embedded Net Imports. The method adds value to the original data by combining both transmission and distribution generation data into a single dataset and adding ISO 8601 compatible datetimes to increase interoperability with other timeseries. Data cleansing is undertaken by visually flagging errors and then using simple linear interpolation to impute values to replace the flagged data points. Publishing the method allows it to be further enhanced or adapted and to be considered and critiqued by a wider community. In addition, the published raw and cleaned data is a valuable resource that saves researchers considerable time in repeating the steps presented in the method to prepare the data for further analysis. The data provide a public record of the decarbonisation of Great Britain's electrical system since late 2008, widely seen as an example of rapid decarbonisation of an electrical system away from fossil fuel generation to lower carbon sources.