Progress of Cryogenics and Isotopes Separation , ISSN: 1582-2575
2017, Volume 20, Issue 1

A hybrid energy storage system and control strategy for stand-alone applications using renewable energy sources

Abstract

The present work proposes a small scale hybrid energy storage system for the energy provided by renewable energy sources (RES) through a wind turbine, several photovoltaic panels and a solar concentrator equipped with a Stirling engine (CSP). As regards the CSP equipped with Stirling engine is well known its working principle and the fact that when it operates can provide energy in cogeneration. The obtained energy from RES could be stored as electricity in Li-Ion batteries, and as thermal energy in the form of hot water used especially as domestic hot water and for heating of the buildings.

In this paper the authors present a hybrid energy storage system together with an application capable to decide at any moment of time what kind of energy to store. By manipulation of the solar concentrator it may be decided if the system will store electricity or electrical and thermal energy in cogeneration. The boiler for thermal energy storage is provided with an internal resistor that could convert electricity into heat if the batteries are fully charged and there is no need for electricity. This option comes in order to cover the consumer’s needs from two points of view, electrical and thermal, and can contribute to achieve the objective of minimizing the cost of energy storage.