Coordinate sizing of energy storage and transmission line for a remote renewable power plant

To protect the environment and reduce carbon emissions, renewable power generation has been growing rapidly during the past decade. Renewable energy resources are sometimes far away from the main grid, leading to expensive grid-connection transmission lines. Deploying on-site energy storage can smooth the output power and help to reduce the renewable power spillage and the requirement of transmission line capacity. This paper presents a method to coordinately size on-site energy storage and grid-connection transmission line for a remote renewable power plant, minimising the total investment cost subject to the constraint of renewable curtailment risk. Through an optimal operation model, the renewable curtailment is proven to be a piecewise affine function of capacity parameters and renewable power generation, and a linear programming-based algorithm is proposed to generate an approximate expression. A distributionally robust optimisation model is proposed to determine the sizes. The renewable generation uncertainty is modelled by a Wasserstein-metric-based ambiguity set containing probability distributions around the empirical distribution constructed from the historical data. The utilisation rate is ensured in the worst-case distribution. The sizing problem is transformed into a tractable linear program. The case study demonstrates the effectiveness of the proposed method.