PLEXOS® Integrated Energy Model

Integrated Energy Model – Gas & Electric
Advanced Visualisation
Gas Modelling

PLEXOS® Integrated Energy Model:
Simulation software for energy market analysis

PLEXOS® Integrated Energy Model (PLEXOS) is tried-and-true simulation software that uses state-of-the-art mathematical optimisation combined with the latest data handling and visualisation and distributed computing methods, to provide a high-performance, robust simulation system for electric power, water and gas that is leading edge yet open and transparent. PLEXOS meets the demands of energy market participants, system planners, investors, regulators, consultants and analysts alike with a comprehensive range of features seamlessly integrating electric, water, gas and heat production, transportation and demand over simulated timeframes from minutes to 10’s of years, all delivered through a common simulation engine with easy-to-use interface and integrated data platform. PLEXOS is the fastest and most sophisticated software available today, and also the most cost-effective.


At its launch in June 2000 PLEXOS was first-to-market with electric power market simulation basedentirely on mathematical programming. Today PLEXOS is the most widely used integrated energy model including the world’s largest and most sophisticated utilities, regulators and system operators. PLEXOS simulation results are renowned for accuracy and robustness and have appeared in numerous publications and are subject to regular and rigorous audits.

Features of the simulator

Integrated Models and Flexible Resolution
Perform long, medium and short-term analysis with one integrated simulation engine. Apply chronological modelling to any simulation mode including capacity expansion planning. Make use of the flexible time resolution including sub-hourly down to one minute resolution.

Optimal power flow with losses fully integrated with dispatch and unit commitment. Security and n-x contingency constraints (SCUC), DC lines and phase shifters. Generic constraints and interface limits, transmission aggregation, Monte Carlo simulation, multiple AC networks, 10,000’s buses and lines, nodal pricing and price decomposition.

Capacity Expansion Planning
Optimise electric power generation, dc and ac transmission line and interface expansion, energy storage and gas field, storage and pipeline expansion planning over long timeframes using mixed integer programming. Minimise expected NPV of investment and production costs with respect to uncertainty in inputs such as load, fuel price, hydro production, etc. Computes multi-area reliability indices. Integrates any long-term constraint e.g. emissions limits.

Power Generation
Perform comprehensive modelling of the economics and technical limits of fossil-fired and renewable generation sources including but not limited to: heat rate curves and multi-fuel operation, minimum operating levels, minimum up and down times, ramping rates, start up and shutdown profiles, CCGT operating modes, and emissions production and limits. Model stochastic processes for wind and solar production, and Monte Carlo for forced and planned outages.

Generation economic dispatch and unit commitment is fully integrated with an optimal power flow covering multiple ac networks and able to compute for 10,000’s buses and lines. Loss modelling and security and n-x contingency constraints (SCUC), dc lines and various types of FACTS. Generic constraints and interface limits, wheeling charges, automatic aggregation of network areas, Monte Carlo simulation of transmission outages, and optimal transmission switching. LMP decomposition and FTR evaluation.

Ancillary Services
Model ancillary service provision co-optimised with generation dispatch and unit commitment to sub-hourly level, with detailed treatment of start-up and shutdown combined with ramping and reserve interaction minute-by-minute. Include multiple reserve classes such as spinning, regulation, up and down and replacement services.

Smart Grid
Evaluate the economics of transmission flow control devices and switching and battery energy storage systems (BESS). Compute potential savings in terms of production costs, congestion charges and reduction in losses.

Hydro-thermal Coordination
Integrate detailed cascading hydro networks with generation efficiency curves, pumped storage, head storage dependency, waterway flow delay times, spillways and evaporation. Perform deterministic and multi-stage stochastic solutions over any horizon. Seamlessly integrate with short-term hydro-thermal coordination problem via hydro targets or future cost function decomposition.

Gas-electric Co-optimisation
Model the physical delivery of gas from production in fields, through pipelines and storage to gas and electric demands. Gas and electric models are solved simultaneously allowing decision makers to trade-off gas investments, constraints and costs against other alternatives.

Water-electric Co-optimisation
Model water supply from desalination through storage and pipeline to demand and integrate with the electric system. Model water use for electric generation.

Maintenance Optimisation
Perform value-based reliability (VBR) to optimise the timing of maintenance events with respect to all system costs and accounting for constraints such as crew limits.

Objective Functions and Models of Competition
Switch between or blend cost-minimisation and price-driven profit maximisation objective functions e.g. price-based unit commitment (PBUC). Utilise the comprehensive financial reporting to Generator, Zone, Region and Company level. Perform dynamic bidding of generation resources reflective of contract position and/or medium term revenue requirements or Bertrand competition. Model Nash-Cournot equilibria to determine the expansion plan and production decisions that maximise profit.

Technology Leader

The following are examples of class-leading features of the PLEXOS system:

  • Co-optimisation of unit commitment and economic dispatch with ancillary services, optimal power flow and locational marginal pricing
  • Power-water-gas integrated simulation allowing the optimisation of investment and production decisions across all commodities simultaneously
  • Monte Carlo and full stochastic optimisation
  • Comprehensive modelling of renewable generation and smart grid technologies with emissions pricing and limits
  • Seamlessly integrated simulation phases from long through medium to short-term, optimising investment decisions and decomposing production constraints and hydro schedules
  • Scalability from single plant or portfolio optimisation to simulation of large-scale systems with thousands of generating units and transmission nodes
  • Simulation resolution from sub-hourly intervals as short as 1-minute through to hourly or dynamically variable resolution



A flexible object-oriented design tightly integrated with state of the art optimisation tools allows PLEXOS to provide unsurpassed functionality across a wide range of planning problems including:

  • Capacity expansion planning
  • Production cost modelling
  • Electric and gas market price forecasting
  • Water and gas infrastructure planning
  • Market analysis and market design
  • Transmission constraint analysis
  • Portfolio optimisation and valuation
  • Operational planning with stochastic optimisation
  • Renewable generation integration analysis
  • Smart grid planning
  • Hydro generation resource management
  • Risk management

PLEXOS is an open system with results that are entirely auditable and comprehensive documentation is available, making it the perfect choice for market designers, regulators, consultants and researchers alike.

Quality tested to ensure the best product and fastest delivery

PLEXOS is built using the “Agile” software development process to meet your demands while delivering the best working software and regularly to you. Read about our quality process in this document and how it can greatly benefit you.
Read about our quality process


PLEXOS supports multiple licensing modes including:

  • Standalone (node locked) licensing
  • USB dongle
  • Server-based licensing

PLEXOS requires a licence for one of the third-party mathematical programming packages listed on our Partners page. These licences are provided with PLEXOS by Energy Exemplar.

PLEXOS software and some of the mathematical programming packages are free for academics, but must be registered with a degree-issuing academic institution.


In a way, my argument is that PLEXOS is at some level an “artisanal” product (not in the hipster/kitschy sense, but in a broader sense), a product made with great care, and also with an aesthetic that delivers real value. That aesthetic in turn generates confidence that PLEXOS is the bridge to some unknown future.
Steven Broad
Energy Exemplar

The savings generated after investing in PLEXOS are many hundreds more than the initial outlay. It’s a no brainer!
Razib Dawood
Energy Commission of Malaysia

I have already been working with PLEXOS for almost a year. I can define my experience with the tool as absolutely enriching and advisable. Since I started working with it, I have been surprised of how powerful and useful it is. PLEXOS covers such extensive and accurate approach of modeling the market and provides different possibilities of modeling the different factors and drivers of the power market. I used PLEXOS to model different power markets across the world, every of which had their own particularities –which implies the difficulty of different approach when modeling- ; thanks to such a powerful tool, the required knowledge and the incredibly great support from energy exemplar, every client case I used PLEXOS for the modeling part, the client happened to be very satisfied with the results and my company as well. I strongly recommend it to those new potential users thinking about joining the PLEXOS practice!
Elena De Juan Salgado
Boston Consulting Group

PLEXOS® is our tool of choice for NEM market modelling. It gives us the flexibility to set up the model as we choose, and its scenario management is very sophisticated, allowing consistent assumptions to be applied to short, medium or long-term outlooks.
Ben Howard

I’ve only been using PLEXOS for a couple of months, but I’m very excited about the flexibility and ease with which I can test a wide variety of different scenarios. By only supplying key inputs I get surprisingly accurate results, which I can confidently stand behind. So far PLEXOS has had more to offer than I’ve needed, and each time when I run into a dead end I get quick responses with from a diligent technical support.
Jacobus Swart

It is truly amazing how Energy Exemplar seem to be breaking new boundaries. Firstly, the introduction of chronological optimisation for the Long Term Optimisation studies seems to be paced right at time where renewables are the “flavour of the moment”. Secondly the introduction of the gas module again peached at the time where shale gas is shaping the market. Not only are the new features paced appropriately, the algorithms and results are truly stunning and this will definitely help to put policy options on a scientific footing. PLEXOS has been fascinating to use to produce the South African Integrated Resource Plan (IRP), the stochastic optimisation aspect of it was helpful to establish the position of least regret, we are more confident that the next IRP will be more informative given that PLEXOS has given us new questions which need answers….
Sipho Mdhluli

In an industry like Energy where advanced analytical solutions are extremely important and demanded, PLEXOS has been the ‘All in One tool’ for us for such analysis, from market modelling to planning, forecasting and optimization. With its perfectly designed GUI, we have saved great effort in formulating complex problems as well as good amount of time with its fast & flexible solver options in simulations.
Mutlu Yildirim
ETRM, Turkey

Wärtsilä has used PLEXOS successfully for several years now. Purpose of our modelling work is to quantify the value of flexibility for power systems and for individual customer portfolios. The studies have clearly identified the need of more flexible generating resources in the future. Ease of creating models from scratch and the flexibility of PLEXOS have been keys for Wärtsilä when creating multiple models over a short time period. Also, Energy Exemplar’s willingness to develop the software, based on our needs, is highly appreciated. Over the years, several features proposed by Wärtsilä have been added to the PLEXOS”.
Ville Rimali

In the last few years I have successfully used PLEXOS for modelling different electricity markets. Its functionality and flexibility to model markets with different rules, the auditability of the optimization problems, the capability to model a market with different levels of detail within a single database, and the possibility of including your own custom-made algorithms through Open PLEXOS sealed the deal for me.
Professor Esteban Gil
Universidad Federico Santa Maria

PLEXOS is an incredibly important tool for any energy market practitioner. It’s fast, flexible and incredibly easy to get started with. The interface is user friendly and efficient to use. I don’t know where my company would be without it!
Dr. Ariel Liebman
Strategic Energy Market Services

PLEXOS gives us the right combination of simplicity and complexity, allowing us to include all of the relevant features of the regions we are studying whilst retaining control over the size of the model. The model framework is flexible and transparent enough to allow us to build meaningful models very quickly, and enables us to easily develop our model as our knowledge of the market changes, as our interests evolve, and as our modelling skills improve.
Paul Andrew Holtom
Statoil ASA

PLEXOS is a valued tool which provides CEZ with more insight into European power and carbon market dynamics. The analysis of fundamental drivers and their impact on the future balance of power systems is beneficial for both trading and investment decision purposes.
Zdeněk Pekárek

We are using PLEXOS for some time now and are feeling comfortable because of its intuitive user interface as well of its solving capacities. Having complex models to be solved, PLEXOS still computes the results in a fair period of time. The graphical solution viewer enables us to quickly check our models’ consistency. PLEXOS helps us understand cause and effect of market characteristics.
Hendrik Heese
Borusan EnBW Enerji


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