About the company
Contact Energy is the second-largest power producer in New Zealand, with 10 generation sites whose capacity exceeds 2 gigawatts. It includes a mix of gas turbine, geothermal, hydroelectric and the trial incorporation of end-user installed photovoltaic into the grid.
The challenge
Contact’s power generation facilities are a hybrid of older and newer technologies. Operator alarms were identified as a challenge and an opportunity for business improvement. Contact identified more than 90,000 configured alarms with inconsistent approaches to their creation, definition and use. Excessively high alarm rates, nuisance alarms and alarm floods at several facilities hindered operators’ ability to respond to alarms effectively.
The solution
Contact Energy sought to address its corporate-wide alarm management challenge by first developing an alarm philosophy to govern the design, implementation and maintenance of the alarm system. Octave facilitated the creation of a comprehensive alarm philosophy in alignment with the principles contained in the ISA 18.2 standard and Octave’s The Alarm Management Handbook (formerly PAS’s The Alarm Management Handbook).
Contact Energy set the goal to acquire a single software platform to manage the alarm systems for four different control systems installed across 10 sites. After evaluating multiple available solutions, Contact Energy chose Tempo Control System Effectiveness (formerly PAS PlantState Integrity) for its robust platform-independent connectivity and comprehensive capabilities.
Tempo Control System Effectiveness provided automated alarm performance reports for all sites, with KPI analyses for alarm rates, priority distribution, frequent alarms, flood analysis, chattering alarms, stale alarms and several others. Contact Energy also implemented the Master Alarm Database and Alarm Audit and Enforcement modules for proper management of change.
Realizing results
Content: As each site received the regular performance reports, the detailed, quantitative analyses enabled immediate alarm improvement by first addressing nuisance alarms. In a four-month period, Contact Energy achieved 60% alarm rate improvements by adjusting alarm setpoints, deadbands, delay-times and improving control logic. Additionally, the company realized a 65% reduction in long-standing “stale” alarms, contributing to a noticeable improvement to the operators’ alarm-related workload.