Multi-objective energy procurement strategy of electricity retail companies based on normalized normal constraint methodology.

• A new multi-objective framework is presented for electricity retailers. • The selling price is calculated based on profits of electricity retailer and customers. • Normalized normal constraint methodology is used to generate the Pareto frontier. The electricity retail market provides a marketplace for domestic consumers and retailers to buy and sell electricity in a competitive environment. Permitting final consumers to choose electricity retailers promotes suppliers' pluralism and clients' freedom, which leads to improvements in the quality of electricity retailing service. The main aim of a retailer and consumers is profit maximization, which highly depends on retail-selling price. Retailer's profit may be explicitly reduced by decreasing retail selling-price or implicitly reduced by increasing retail selling-price as increasing these prices may decrease clients' consumption. Accordingly, the retail selling-price, retailer energy procurement strategy, and clients' consumption should be simultaneously analyzed from the viewpoints of retailer and clients. In this paper, a multi-objective optimization problem is introduced to obtain the retailer's energy procurement strategy in terms of the profits of energy buyers and sellers. Moreover, the normalized normal constraint method as a proficient multi-objective optimization technique is utilized to solve the proposed multi-objective optimization problem determining the retailers' energy procurement strategy and retail selling-prices. Since the wholesale energy price is a highly volatile uncertainty source affecting the retailer's profit, the point estimate method is utilized to characterize the uncertainty of the wholesale energy price. Simulation results illustrate the effectiveness of the proposed non-deterministic multi-objective optimization problem. [ABSTRACT FROM AUTHOR]