Co-Planning of Electricity and gas Networks Considering Risk Level Assessment

What is it about?

This paper provides a Risk-based Gas and Electricity Expansion Planning model to coordinate expansion of electricity and gas networks in a multi-carrier energy network. Generally, electricity and gas networks have separate owners having no mechanisms to share information. In this paper, a distributed algorithm based on Alternative Direction Method of Multipliers (ADMM) is developed to preserve the privacy of electricity and gas networks while maintaining a coordination link. Probabilistic outage of components is implemented into the expansion planning model to investigate the interactions between electricity and gas networks and evaluate the risk of contingencies in generating units, transmission lines, and pipelines. Second fuel of Gas Consuming Generating Units is modeled to have a holistic approach while studying electricity and gas interactions in the case of contingencies. Moreover, Conditional Value at Risk (CVaR) is used to adjust a balance between risk and investment where each of energy parties can decide on the risk level of their expansion plans. The proposed expansion planning approach is applied to a realistic case study to evaluate its performance.

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Photo by American Public Power Association on Unsplash

Photo by American Public Power Association on Unsplash

Why is it important?

In the current researches of gas-electricity expansio planning, second fuel is not considered and risk level assessment is still a gap. Although GCGUs generally operate in gas-driven mode, sometimes they employ another type of fossil fuel rather than gas as a back-up plan in the case of emergencies, making it a necessary element in a fuel-related contingency analysis. Also, N-1 security criterion does not take probability of contingencies into account, which potentially increases investment cost. Hence, while a robust planning scheme leads to an over investment, considering probability of contingencies and second fuel of GCGUs contribute to a realistic approach and are of significance in contingency analysis of electricity and gas networks. In addition, CVaR can play a key role in mitigating these shortages in the literature effectively as it offers flexibility in the accepted risk level. Besides, it can introduce a risk-oriented model in which, each of the network operators, i.e. gas and electricity networks, has freedom of expression in specifying their risk aversion level. In the meantime, using the co-planning model introduced in this paper, they are operated separately, maintaining their data privacy.