Optimization of a wind-power fuel-cell hybrid system in an autonomous electrical network environment

Stability considerations associated with intermittency prevent high wind energy penetration in small electrical networks. The case of the islands of the Aegean is presented. [Ntziachristos L, Kouridis C, Samaras Z, Pattas K. A wind-power fuel-cell hybrid system study on the non-interconnected Aegean islands grid. Renewable Energy 2005;30(10):1471–1487] proposed a wind turbine(WT)–fuel-cell hybrid as a means to store wind energy and increase penetration in these islands. The effect of network restraints was, however, not included in that study. Simulation results including network restrictions prove that when network restrictions are relatively “strict”, hybridizing a WT using the scheme presented in the same paper will indeed increase the WT's energy output. However, in the case of “lenient” network restrictions, that hybridization scheme will in fact decrease the WT's energy output. Moreover, the system configurations presented that paper could not achieve financial viability at current electricity prices due to high capital costs. Two alternative operating principles for the hybrid system are presented in this study. These operating principles significantly improve the hybrid system's energy performance even under “lenient” network restrictions. In some cases, these operating principles manage to yield hybrid systems that are financially viable assuming current electricity prices.