Eskom's transmission network expansion programme has been delayed, and the inability to connect new wind and solar farms, because of network unavailability, has become a problem.
Curtailment is the programmed and contracted reduction in output of renewable energy plant due to low demand or network congestion. Curtailment carries an economic cost as it results in generated electricity being unsold. It is implemented either when there is a system-wide oversupply, or when there are transmission constraints, and is commonly practiced in most networks.
