Long-term electricity procurement portfolio optimization

This paper addresses the long-term electricity procurement portfolio optimization problem faced by an electricity Retailer. Differentiated asset options are considered to fully cover the forecasted electricity consumption represented by the Retailer, such as investing in new RES plants, a new CCGT unit, new battery energy storage systems and procuring electricity directly from the wholesale electricity market. A novel optimization model that takes into account the inherent technical and operating characteristics and constraints of each asset option as well as various financial parameters was formulated for the quantification of the timing, capacity and overall cost of the optimal mix that covers the Retailer's forecasted load portfolio in the most efficient way on a yearly basis. Multiple scenarios were formulated to capture the effect that the anticipated day-ahead market prices, the expansion of the Retailer's customer base, the incorporation of budget constraints that reflect the desired longterm investment strategy of the Retailer as well as the selection of common economic valuation parameters may have on the optimal mix of asset options. A case study on the long-term strategy (2021-2030) of a growing Retailer that participates in the Greek electricity market is presented illustrating the applicability and effectiveness of the proposed optimization model.