Case Study: Avista improves hydro plant availability and capacity with ARMS Reliability

Avista Utilities improves Availability and Capacity with Optimized Preventative Maintenance

Avista Utilities, a regulated power generation utility in Spokane, Washington, needed to decide how much maintenance and replacement investment was justified for its aging Little Falls Hydro Electric Development, where much of the original equipment was still in service. With rising energy costs, limited budgets, and the need to balance reliability with customer value, Avista turned to ARMS Reliability for maintenance strategy optimization using Availability Workbench.

ARMS Reliability helped Avista build a detailed reliability model of the plant, test maintenance, inspection, spare-parts, and replacement scenarios, and compare short- and long-term outcomes. The optimized strategy showed that while the base case was better over 10 years, the optimized spares and maintenance case delivered much better 50-year results, improving availability from 0.98665 to 0.9976, increasing average capacity from 19.32 MVA to 21.55 MVA, and reducing consequence costs from $247.9 million to $125.4 million. Including consequence costs, the optimized case improved customer economics with a lower levelized gross margin requirement and about $124.5 million in avoided power purchase/opportunity costs over 50 years.

Avista