Design and Optimization of Hybrid Electrical Energy Storage System for Grid Connected Wind Energy

Connecting the energy generated from wind resources to the grid presents some challenges due to variation of wind profile. The energy produced from wind source varies proportionally to wind speed, if the wind generators are connected to the grid system, it may cause power fluctuations into the grid side and even to the consumers. Installation of electric energy storage system (EESS) between wind generator and grid system can reduce the wind intermittency effects on the power quality. The storage system can be configured into hybrid configuration to enhance the performance of each storage technology. This paper proposes a well-designed and optimized HEES system connected between wind generator and grid system. Economic feasibility of HEES system composed by a lithium-ion battery bank, supercapacitor bank and pumped hydro is conducted. The system is optimized and simulated by HOMER software. After simulation, the results show that at the average annual wind speed of 8m/s, the economics metrics are higher. The internal rate of return is 29%, Net present value is 480${\$}$ Million, return on Investment is 25%, levelized cost of electricity is 0.0340${\$}$/kWh and payback period are 3.5 years. While at annual average wind speed of 4. 90m/s the internal rate of return is 17%, the Net Present Value is 216 million, the return on investment is 13%, levelized cost of electricity is 0.0244${\$}$/kWh and the pay period is 5.8 Years. To make a HEES project more profitable, the site must have a higher annual wind speed.