According to Information Received from Eskom:
1. Battery storage is used by Eskom to support the network during peak loading and ancillary services such as frequency regulation and voltage support.
However, gas is used as mid-merit or peak generation, depending on the prices. Gas can power the network on a continuous basis.
The costs of battery storage cannot be directly compared to those of gas, as battery storage has charging and discharge components. Charging costs and discharging costs differ.
Gas costs are only for electricity generation.
In addition, the use of gas would require new pipelines and gas distribution networks to Eskom substations. The country would have to invest in new gas pipeline networks, and these would need to be built underground and protected which would further increase costs.
2. Storage that would be currently required is about 70% of the installed solar photovoltaic (PV) and wind capacity to ensure power supply continuity equivalent to baseload generation. The storage capacity must accommodate load shedding cycles to be effective. The battery storage costs are in the peak generation range. Using current battery energy storage costs of R11bn for 200M/800MWh, an installed PV base of 5000MW would require 3500W/14000MWh a day at an estimated installation cost of over R192bn noting that this excludes operational costs.
Remarks: Approved / Not Approved
Ms Jacky Molisane PJ Gordhan, MP
Acting Director-General Minister
Date: Date: