Unscheduled outages at power stations are caused by breakdowns or unplanned maintenance. These can be full unit trips where generation from falls to zero or partial unit trips where generation drops significantly. We monitor the National Energy Market’s fossil fuel power plants and report on breakdowns from this ageing unreliable technology. Similar to the Australian Energy Market Operator’s definition, breakdowns are all unscheduled outages – either full unit trips where generation from a unit falls to zero or partial unit trips where generation drops significantly.