Optimisation of Energy Storage to Reduce CO2 Emissions

Abstract

The penetration of PV solar energy in South Africa is driven by lower cost and government policies which support the development of renewable energy projects. Most of the renewable energy sources like wind and solar which are produced in large scale are intermittent and need to be stored for future use. The penetration of renewable energy sources without effective energy storage can cause grid instability, unstable power supply and loss of generated cleaner energy which is required to offset CO2 emissions. Energy storage technologies can help to integrate higher penetrations of low-carbon renewable energy into the electric system. A number of utility-scale energy storage technologies are being developed, including compressed air energy storage, electrochemical batteries and capacitors, and flywheel energy storage. Among the bulk energy options, pumped hydroelectric energy storage (PHES) is the most widely deployed utility-scale energy storage technology A simplified optimisation model was developed using General Algebraic Modelling System (GAMS) to determine the optimum energy storage capacity that is required to reduce CO2 emissions. To our knowledge, this is the first time such an assessment has been reported since majority of optimisation model focuses on the cost rather than CO2 emissions. These results will provide the power utility with key results to reduce CO2 emissions without considering the cost of the energy storage.