Cost effective battery storage for intermittency of solar

Abstract

Renewable energy, especially Solar Energy, has become a popularly sought solution for the current energy situation in Sri Lanka. It is included in the ‘Long Term Generation Expansion Plan of the Ceylon Electricity Board (CEB)” as well [1]. However, the unpredictable, varying and intermittent nature of the solar hinder all these plans. Wide varying nature of solar power is such that the daily infeed may vary within 20% to 90% of the installed during the same week. Said constant power fluctuations and the inability to control the infeed utilizing system inertia lowers the quality of service provided to the CEB by the power producers. This impacts adversely on the interest towards solar from both the sides; CEB and the power producer. To overcome this problem, the CEB recommends solar producers to install a battery storage to store the energy produced during daylight hours enabling that energy to be utilized later. This recommendation has not been welcomed by the producers due to cost related issues. Hence, this research proposes a more economically feasible solution for the discussed matter. It consists of a forecasting system to predict the solar power output sufficiently in advance to the CEB System Control Center and a relatively smaller battery storage equipped with an automatic switching mechanism to maintain the predicted output. This value-added solar output should be rewarded under an updated tariff scheme.