vSPD overview

vSPD stands for vectorised Scheduling, Pricing and Dispatch and is a precise replica of the SPD model. It is written and solved using the GAMS software and is based on the published SPD formulation. vSPD takes advantage of the computational efficiency of modern linear programming and mixed integer programming solvers through vectorisation of some schedules prior to solving. Vectorisation involves reformulating the sequential trading period problems as a single optimization, requiring just a single solve for the entire vectorised set of schedules. In other words, vSPD is typically configured to solve an entire day, or 48 trading periods, at once.

The input data for vSPD is provided in the form of GDX files. Daily GDX files for use in vSPD can be found in Datasets.

vSPD output is generated as a collection of GDX and CSV files, which report on generation, load, prices, branch flows and reserves.

















Audit and certificate of compliance

vSPD is regularly audited by the same independent auditors contracted by the system operator to audit SPD each time a change to the SPD formulation is implemented.

The most recent audit of vSPD was undertaken in September 2014 by the PA Consulting Group. Their approach to testing and the statement by the PA Consulting Group of vSPD's fitness for use are explained in the vSPD certificate of compliance.

vSPD certificate of compliance

Last updated: 12th September 2014

Download and install vSPD

Development of vSPD is ongoing. Soon after vSPD has been audited, it is likely to be modified in some way although at all times it will replicate SPD for all published schedules. We don’t have vSPD audited after every modification; some changes are quite trivial. Version 3.0.3 of vSPD is consistent with commit 787d9a1 on the vSPD GitHub repository.

Most recent version of vSPD

Last updated: 1st March 2017

Last audited version of vSPD

Last updated: 12th September 2014