Hydropower Facility Modernization

One of our utility clients, located in northern California, has been providing quality water to the region for more than 100 years. Today, the utility has grown into a multifaceted water and power agency, operating multiple powerhouses, including a 39-megawatt hydroelectric facility. This facility faced reliability and operational challenges due to aging system components.

To continue efficient electricity generation, the utility needed to understand the condition of its equipment and contemplate making substantial capital expenditures. The utility sought a partner to guide future improvements, maintain unit reliability, and determine the feasibility and economic viability of increasing the power output of its turbines and generators.

Hydroelectric powerhouse refurbishment projects enable utility owners to extend the useful lifecycles of their facilities, enhance efficiency and dependability, and boost power generation capacity. Over the past 50 years, the facility has deteriorated while regulations and energy market dynamics have changed. It was essential to determine which components could be repaired and which portions of the system needed to be replaced, substantially refurbished, or upgraded. GFT conducted a multi-phase powerhouse condition assessment of the critical systems, including the hydro turbine, generator, and balance of plant.

The first phase focused on detailed project scoping, equipment testing, and feasibility studies to assess the potential for increasing the unit’s capacity. This included an uprate feasibility study to evaluate the possibility of increasing the power output, which involved cost-benefit analysis and equipment efficiency evaluations. The analysis also examined the utility’s potential revenue increase to determine the return on investment.

The second phase of the project identified which original equipment could be replaced, refurbished, or upsized without compromising system safety or functionality. This required a comprehensive evaluation of the entire system, beyond the hydropower plant’s physical assets and controls system. Our team assessed flow data, water availability and head potential, and system performance, along with their respective impacts on the hydro facility’s operations.

We facilitated all stakeholders in a workshop to weigh the pros and cons of various scenarios, discuss cost estimates, and make final recommendations, which included:

• Equipment maintenance and refurbishment: Complete generator cleaning while concurrently strategically preparing for a generator rewind, maximizing upcoming outage opportunities.
• Electrical system improvements: Generator maintenance, generator stator ground protection relay installation, generator step-up transformer online monitor installation, and a gantry crane investment for rotor inspection and maintenance.
• Mechanical equipment maintenance, replacement, and refurbishment: Runner and seal removal and restoration, replacement of turbine and wicket gates, draft tube reconstruction and restoration, canal maintenance, pipe wall thickness testing program initiation, and regular inspection and maintenance scheduling.