Energy Modeling Consultants Ltd

Projects


Ensuring Sustainability of Greater Mekong Sub-region Regional Power Development

A Strategic Environmental Assessment (SEA) process was carried out to assess the regional power development plan of the Greater Mekong Subregion (GMS). This region consists of Cambodia, Laos, Myanmar, Southern China, Thailand and Vietnam. In addition to the existing plans, four alternate scenarios were developed and comparative analysis carried out, including detailed assessments of the environmental, social and economic impacts of each scenario. This project was carried out for the Asian Development Bank by the consortium of the International Centre for Environment Management (ICEM) and Economic Consulting Associates (ECA).

Dr Halliburton carried out the power system dispatch analysis for this project, using the optimal generation system planning model, OptGen. This required updating and revising the data base for the four Lower Mekong Basin countries (Cambodia, Laos, Thailand and Vietnam) to incorporate their current power development plans. Reconciling inconsistencies in the power plans of the various countries was a difficult task. For example one country would show exports to a second, but the power plan for that second country did not always include the corresponding imports. Incorporating new information regarding power developments that were not included in the official power plans was also an important aspect of this work - it was necessary to balance the credibility of the study with the need to freeze the database to allow analysis to proceed.

The OptGen database included 330 thermal and 280 hydro plants along with 50 interconnections and covered the period 2012 to 2025.

OptGen was solved to determine an optimal program of expansion of interconnections between the countries taking into account capital and operating costs and transmission losses, but keeping the power development plans fixed. OptGen produced an optimal dispatch for the entire region, allowing the calculation of emissions and other environmental effects of the planned power system by other members of the SEA team..


Water Valuation System Implementation, Vietnam

In Vietnam, a competitive electricity generation market is being established in which hydro generation bids are required to be based on water values calculated by a system-wide optimisation model. The project involved the selection of suitable software, setting up a data base and the training of local people in the use of the model. The project had a strong emphasis on capability building within the Vietnam National Load Dispatch Centre, located in Ha Noi. While local staff had significant modeling expertise, this was limited to deterministic models. Developing suitable inflow data, and transferring expertise in the use and interpretation of the outputs from a stochastic model were key features of the project. This project was funded by the World Bank.


Options to Reduce Fossil Generation in Mindanao, Philippines

This World Bank funded study reviews renewable energy options in Mindanao to determine a strategy for reducing the use of fossil fuels for electricity generation. The project reviewed existing feasibility studies and also considered the status of other less thoroughly investigated resources. Transmission system issues were also required to be investigated, to assess constraints on generation developments.

Mindanao currently has approximately 800 MW of fossil plant and 1100 MW of renewables capacity. To effectively model the variability of hydro generation from year to year, and from month to month, a stochastic hydro-thermal optimal dispatch model was required. Lake Lanao provides a seasonal water storage capability, so realistic modelling of the operation of this lake was essential. To enable transmission system impacts on future developments to be assessed, it was essential that a detailed model of the grid be incorporated in the dispatch model. Due to the variability of hydro system generation, transmission system power flows are also more variable than would be expected in a purely thermal power system. This makes an embedded power flow even more important.

Dr Halliburton used the Stochastic Dual Dynamic Programming model (SDDP) for this study. Some potential transmission system bottlenecks were identified, and a ranking for 18 potential projects was produced.


Hydro-Thermal Electricity Market Simulation Model

This project was carried out for Contact Energy Limited, New Zealand, with assistance from our Associate, Dr Jonathan Lermit. Simulating the operation of an electricity market involving substantial amounts of hydro power, with storage reservoirs, is considerably more difficult than for a system consisting only of thermal power plants. The hydro-thermal system can experience high prices at times when ample generating capacity is available because the system is often energy constrained, or a possibility of the system becoming energy constrained may exist. To represent this aspect, a stochastic hydro-thermal optimisation model is incorporated which represents both hydro storage lakes and the effects of thermal power plant fuel stockpiles.

The market simulation calculations find a Cournot Equilibrium, in the presence of transmission constraints. When transmission lines become constrained, market prices at either end of the line can diverge significantly. The number of generation companies, the extent to which the companies are hedged against spot market volatility, and the market's effective price elasticity are considered by the market equilibrium process. Solutions are calculated out repeatedly by the model enabling market price trajectories to be calculated for a number of possible inflow outcomes over any number of time periods.

The market simulation calculations find a Cournot Equilibrium, in the presence of transmission constraints. When transmission lines become constrained, market prices at either end of the line can diverge significantly. The number of generation companies, the extent to which the companies are hedged against spot market volatility, and the market's effective price elasticity are considered by the market equilibrium process. Solutions are calculated out repeatedly by the model enabling market price trajectories to be calculated for a number of possible inflow outcomes over any number of time periods.


Hydro Power River System Scheduling

Pacific Gas and Electric Company operate a number of hydro generation systems on separate river systems in Northern California. A set of hydro dispatch models was developed for use in day ahead and near real time planning by area dispatch centres.

A comprehensive model was in use at the central operations control in San Francisco, but this model was not able to adequately address some of the more complex operating constraints. Detailed dispatch was delegated to local dispatch centres, where a model giving schedules suitable for real time implementation was required. Working closely with dispatch centre staff, Dr Halliburton developed models customised to the needs of each of the five locations. These models utilised an Excel spreadsheet interface, Visual Basic coding, Dash Optimisation's Mosel modelling language, along with the Xpress-MP mixed integer LP solver. This design enabled very rapid development, and facilitated customised models for each location - a key feature in obtaining the support of local operations staff.


Electricity Market Simulation, Ukraine

Ukraine is changing its electricity market form a centralised pool arrangement to an alternative – the Bilateral Contracts with Balancing Market system. To assist participants in gaining familiarity with the new arrangements, a simulation model was required which would enable a group of participants to follow through the various steps involved in the operation of such a market. These steps include establishing bilateral contracts between generation and supply companies, bidding into a voluntary power exchange, scheduling generation to meet contracts, bidding into the balancing market, simulation of dispatch, including transmission constraints, and calculating settlements. The simulation model included power exchange and balancing market clearing processes, and determined transmission constraints on the very large Ukrainian power system.