In conjunction with the tutorial document, available at, use the app to learn about electricity markets by graphically building and solving your own electricity market models. The tutorial also describes the simplex algorithm that solves the model and the app lets you see the internal workings of the algorithm.

This is the paid version of the app, with no limit on the number of solves. (There is also a "tutorial" version which is free... the free version is identical except that it is limited to 12 solves).

The tutorial and the app cover features of nodal electricity markets such as: locational marginal pricing, line losses, parallel flows, binding constraints, price separation, the spring washer effect, risk and reserves, ramp-rates, congestion charges, transmission rentals, multiple electrical islands, HVDC branches, HVDC risk, HVDC risk subtractor, HVDC reserve sharing, and more.

See for more screenshots and the tutorial document.

• The tutorial explains nodal electricity markets and the simplex algorithm via worked examples using the app
• Start with small models to learn the basic concepts of the electricity market model the simplex algorithm
• Learn how to explain prices by relaxing constraints to determine shadow prices
• Enable/disable electricity market features to focus on individual effects, e.g., risk and reserve is easier to explain with line losses disabled
• View full details of the simplex modelling including basic and non-basic variables, constraints, shadow prices, and details of the simplex iterations
• Learn how the simplex algorithm works by viewing the step by step simplex operations that solve the electricity market model. View iteration details in the app and/or export the simplex tableaux as a csv file
• The app implements its own simplex algorithm but you can also export the model in GAMS format to solve externally if you have access to the GAMS solver
• Includes sample models that represent sections of an actual electricity market

iPhone and iPad functionality is the same. Zoom and scroll allow the iPhone to access iPad sized models.

What's New

Version 2.2

Fixed the GAMS export, which was working when reserves and losses were included (the sample that was used for testing), but failing for the simpler models when reserves and/or losses were disabled. Also some minor refactoring of the code, all appears to be well, but please report any issues.


Simplex Nodal Limited
3.3 MB
Requires iOS 8.0 or later. Compatible with iPhone, iPad, and iPod touch.
Age Rating
Rated 4+
© 2017 Simplex Nodal Limited


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    With Family Sharing set up, up to six family members can use this app.

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