Optimized seasonalization of assured energy in the Brazilian power system

The Brazilian power system is a hydrothermal system mainly composed of hydroelectric generation. In order to deal with the uncertainties related to future water inflows a hydroelectric power plant receives an assured energy certificate. In general, those assured energy certificates correspond to energy that each plant can produce considering a 5% risk of energy not supplied. Also, they represent the maximum energy each hydro unit can contract. So, the hydro generators determine their portfolio of energy contracts with free consumers, distribution companies and trading companies constrained by their assured energy. This portfolio is composed of bilateral contracts that are, mainly composed of long term contracts negotiated before the power delivery. Also, considering that the assured energy is constant, each generator can distribute (seasonalize) it in a monthly basis, but keeping the total annual assured energy. This paper aims to optimize the financial profiles of generation utilities in the Brazilian power market considering the seasonalization of the assured energy. To do so a parameter adjust algorithm, the Twiddle, is used. Results obtained show a considerable improvement in the revenues of a generator utility from the Brazilian system.