Powering Vietnam’s Energy Market Operations with PLEXOS®

Supporting Market Clearing in a Growing Power System

Vietnam’s power system has expanded significantly over the past two decades, with growth in generation capacity, transmission infrastructure, and renewable energy. As system complexity increased, so too did the demands placed on market clearing, scheduling, and operational decision-making.

NSMO, Vietnam’s National Power System and Market Operator, operating under the Ministry of Industry and Trade (MOIT), is responsible for operating the national power system and administering the power market in accordance with market rules. To support these responsibilities, NSMO adopted PLEXOS® for power system and electricity market planning and, importantly, for spot-market scheduling and settlement calculations.

After years of proven success in analytical studies, PLEXOS® is now entrusted with the critical task of central market clearing in Vietnam, operating on a 30-minute dispatch cycle.

Modernizing Market Clearing   

Spot-market scheduling involves selecting the least-cost combination of generators needed to meet demand while considering operational and network constraints. Prior to adopting PLEXOS®, short-term market clearing relied on a legacy system that had been in place since 2003.

As Vietnam’s generation fleet and transmission network expanded, particularly with increasing renewable capacity, market clearing became more computationally intensive. In some cases, the clearing process required significant computation time, which affected the timeliness of calculation and operational decision-making.

With the market currently operating on a 30-minute dispatch interval and considering shorter intervals in the future, NSMO required a more scalable market-clearing framework that is capable of handling detailed constraints and larger system representations.

Representing Vietnam's Market in PLEXOS® 

Together with Energy Exemplar, NSMO developed a detailed market model in PLEXOS® that reflects Vietnam’s system structure. The model represents three primary regions, North, Central, and South, connected through the 500 kV transmission network. In addition, NSMO is currently studying the development of more detailed multi-node models, including lower voltage levels such as 220 kV and 110 kV.

Generators participate in the spot market through structured offers composed of 10 bid blocks per interval, each specifying quantities and prices. The model incorporates generator technical characteristics, including:

• Maximum capacity
• Minimum stable operating levels
• Ramp-up and ramp-down limits
• Must-run requirements
• Fixed losses

Transmission constraints and system limits are also represented to ensure that market clearing reflects network realities.

Process Automation and Cloud

To support operational use, NSMO implemented automated data exchange between internal systems and PLEXOS®, allowing generator parameters, bid data, and constraints to be updated consistently for each clearing run.

Cloud-based execution has significantly reduced runtimes for longer-term planning studies, with some models achieving reductions of approximately 50% to 60%, enabling broader scenario analysis alongside operational scheduling.

Supporting Renewable Integration and System Constraints 

With renewable energy representing a growing share of installed capacity, market clearing must account for periods when renewable output remains high while system demand is low. In such conditions, dispatch decisions require careful consideration of operational limits and transmission constraints.

NSMO uses PLEXOS® in conjunction with other analytical tools to evaluate congestion and stability considerations. These inputs inform market-clearing outcomes and support redispatch decisions across hydro and thermal resources when necessary.

Strengthening Consistency Across Planning and Operations

Using PLEXOS® across planning, scheduling, and settlement workflows has allowed NSMO to apply a consistent least-cost optimization framework across multiple time horizons.

This supports:

• Improved alignment between planning studies and operational scheduling
• Faster runtime performance compared to legacy systems
• Detailed representation of technical and market constraints
• Enhanced ability to evaluate renewable-heavy and low-load scenarios

By incorporating PLEXOS® into its market-clearing and operational processes, NSMO has strengthened its analytical foundation while maintaining consistency between system studies and live market operations.

Supporting Vietnam's Evolving Market Design 

As Vietnam’s electricity market continues to evolve and expand in scale and complexity, the demands on market clearing will only increase. Shorter dispatch intervals, higher renewable penetration, and growing network constraints require tools that can consistently balance cost, reliability, and operational feasibility.

By applying PLEXOS® in both analytical studies and market-clearing processes, NSMO is moving toward a more consistent optimization approach between planning and operations. This provides a foundation to support future market development while improving transparency and consistency in dispatch outcomes.