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vSPD overview

vSPD stands for vectorised Scheduling, Pricing and Dispatch. The vSPD model is a precise replica of SPD. 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 by vectorising many SPD schedules prior to solving. Vectorisation involves reformulating the sequential and independent problems as a single optimization and therefore requires just a single solve for the entire vectorised set of schedules. In the case of final pricing prior to the advent of real-time pricing on 1 November 2022, this meant that all 48 trading periods from a single day were solved as a single optimization. Post 1 November 2022, the sequential and independent problems comprise all real-time dispatch SPD cases from a single day, i.e. approximately 250 sequential and independent problems are solved 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 here or here for GDX files for dates prior to 1 November 2022

vSPD output is generated as a collection of GDX and CSV files that report on the key model outputs such as generation, prices, branch flows and reserves. Some inputs to the model, for example load, are also included in the output reports.

An online version of vSPD called vSPD-online is available for use from within a web browser and without the need to learn GAMS or acquire the GAMS software. Under the hood, vSPD-online is identical to vSPD, it uses the same input GDX files, and will generate an identical solution to an equivalently configured run of vSPD. However, the range of what-if scenarios that can be explored, while still quite substantial, is less than can be undertaken by users that have access to vSPD.

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 August 2019 by Robinson Bowmaker Paul (RBP). The RBP approach to testing and their statement of vSPD's fitness for use are explained in the vSPD certificate of compliance.

vSPD certificate of compliance

Last updated: 29 August 2019

Download and install vSPD

Development of vSPD follows that of SPD – each time a change is made to SPD, an equivalent change is made to vSPD. Consequently, soon after vSPD has been audited, it is likely to be modified. At all times, however, vSPD will replicate SPD for all published schedules. vSPD will next be audited in 2023 following the implementation of the dispatch notification product, the final phase of the real-time pricing project. Be aware that with the release of v4.0.0, vSPD is no longer backward compatible. GDX files for dates later than 31 October 2022 will require v4.0.0 or later whereas GDX files prior to 1 November 2022 will require v3.1.0.

All three versions of vSPD available below are also downloadable from the vSPD GitHub repository:

  • v4.0.0 is consistent with commit signature d9e53ae and will work with all GDX files from 1 November 2022.
  • v3.1.0 is consistent with commit signature 69784aa and will work with all GDX files up to and including 31 October 2022.
  • v3.0.4 is consistent with commit signature 967c236.
v4.0.0 of vSPD

Last updated: 13 November 2022

v3.1.0 of vSPD

Last updated: 17 October 2022

Last audited version of vSPD

Last updated: 29 August 2019

vSPD education
vSPD-online: Getting started and fundamentals

Category  - Wholesale 23 months ago

Wholesale price/demand sensitivity

Category  - Wholesale 81 months ago

GDX files for vSPD

Category  - Wholesale 34 months ago

vSPD education
vSPD-online: Getting started and fundamentals

Category  - Wholesale 23 months ago

Wholesale price/demand sensitivity

Category  - Wholesale 81 months ago

GDX files for vSPD

Category  - Wholesale 34 months ago

Latest vSPD-online jobs
TakapoB

A simulation of how the market, from 5:00 pm on 19 February 2022 to 8:00 pm on 22 February 2022, would have been settled if 160 MW at Takapo B had been priced at $0.01/MWh for all trading periods.

Created by  - Viktoria Nordstrom Today

V N

A simulation of how the market, from 5:00 pm on 19 February 2022 to 8:00 pm on 22 February 2022, would have been settled if all generation at Takapo B had been priced at $0.01/MWh

Created by  - Viktoria Nordstrom Today

February 2022

A simulation ofhow the market, from 5:00 pm on 19 February 2022 to 8:00 pm on 22 February 2022, with regards to South Island nodes only, would have been settled if the offers at Takapo B had been the same as those from Takapo A.

Created by  - Viktoria Nordstrom Yesterday

October 7 no HVDC outage

I want to see how the market would have been settled on the morning of 7 October 2022 if there had been no HVDC outage that morning. The HVDC capacity decreased from 1108 MW to 746 MW at 5am and returned to 1173 MW at 7:30 am.

Created by  - Viktoria Nordstrom 2 days ago

Testing Scenario 2

Test 2

Created by  - chewdav 17 days ago

Latest vSPD discussions
vSPD-online: Getting started and fundamentals

Category  - Wholesale 23 months ago

How are outages modeled in vSPD?

Category  - Wholesale 27 months ago

GDX files for vSPD

Category  - Wholesale 34 months ago

vSPD training workshop – Feb 2020

Category  - Wholesale 36 months ago

Latest vSPD discussions
vSPD-online: Getting started and fundamentals

Category  - Wholesale 23 months ago

How are outages modeled in vSPD?

Category  - Wholesale 27 months ago

GDX files for vSPD

Category  - Wholesale 34 months ago

vSPD training workshop – Feb 2020

Category  - Wholesale 36 months ago