Green Power Island, a Blue Battery Concept for Energy Management of High Penetration of Renewable Energy Sources with Techno-Economic and Environmental Considerations

摘要

Extraction of the wind and solar energy is a sensible and affordable solution for satisfying the electricity demand of islands, which are isolated from the electricity network and hardly have access to primary energy carriers such as gas and oil. Being an intermittent and uncertain source of energy, wind units and photovoltaic power plants are encountered with some difficulties to provide pledged power. These uncertainties threaten the security of microgrids and mitigate the reliability of the electricity served. Energy storage units' function as an effective solution for redressing the imbalances and dealing with the uncertainty of wind and solar resources. The utilization of pumped-hydro storage and compressed air energy storage require special geological criteria which often is not viable in islands. On the other hand, the capital cost and replacement and maintenance costs of electrochemical batteries are significantly high in long-term. Hence, the concept of green power island involving the idea of blue battery energy storage has been conceived, which is an attractive solution to exploit the potential energy of water in depth and operate as utility-scale energy storage. The blue battery is a huge reservoir below the sea level located close to the island which functions similar to a pumped-hydro storage power plant. In this study, an operation model for a microgrid encompassing renewable sources along with blue battery concept for an isolated island is proposed. The model outlines how the operator can manage the microgrid to mount the penetration of free green energy.