Integration of Sustainability Criteria in Power Generation Investment Plan
The usual approach of power producers is to establish the master plan for future investments considering only the project’s economical value. Environmental and social impacts are tackled later on and mitigated when possible. This research suggests to integrate sustainable development considerations at an earlier stage in the process and observe the changes in the units chosen, the cost and the socio-environmental performance.
In collaboration with Tractebel Engineering, a current tool for investment planning has been modified to integrate sustainability. This has encompassed the following steps. Sustainable development indicators have been defined and the corresponding data gathered for each type of power plants. The code of the model has been changed in order to include new parameters, variables and a multi-objective optimisation. Finally, it has been validated on a simplified case and several multi-objective optimisation methods have been tested. It has appeared that the weighting objectives and goal programming methods are the most appropriate, with a preference for the former due to computational effort.
The tool has then been applied to the project of the West African Power Pool (WAPP), a collaborative development of the power system for the ECOWAS (Economic Community of West African States) countries. The results have shown that the multi-objective optimisation on socioenvironmental impacts with a constraint of 5% deviation on cost led to a disappearance of the investments in coal and a severe reduction of hydropower plants. The weighting objectives method has favoured natural gas combined cycles over hydropower whereas the goal programming method has shown the opposite trend. It can be concluded that, while the integration of sustainability in the model has succeeded in decreasing the socio-environmental impacts, it has not permitted the emergence of renewables such as solar photovoltaic, wind or solar thermal.