Optimizing a MINLP problem for the grid-connected PV renewable energy consumption under Spanish regulations
José M. Gutiérrez, Beatriz Abdul‐Jalbar, Joaquı́n Sicilia, Luis A. San-José
Abstract
This paper concerns the problem of electricity consumption of a grid-connected photovoltaic renewable energy system under the net billing mechanism of the new Spanish regulation. The goal is determining the optimal photovoltaic solar kit grid-connected sizing with battery storage that minimizes the average energy cost throughout a finite planning horizon fulfilling the energy requirements in each period. To this end, a MINLP problem is formulated and solved to optimality by means of a linearithmic time algorithm based on the description of the extreme solutions of the problem and the binary search of the optimal sizing of the solar kit. It is proved that, under stationary weather and environment conditions, the battery storage is not necessary. This latter finding is aligned with previous results in the literature. Additionally, a computational experiment to analyze the profitability of the solar kit investment is performed. From the computational results, it can be drawn that, when the input data ranges within the intervals offered by the main Spanish retail companies and PV kits suppliers, the solar kit is only worth investing in when the number of periods in the planning horizon is on average above 1000 billing cycles. This experimental finding corroborates that the use of grid-connected PV energy systems is suitable for long-term investments, as claimed in foregoing research.