O&M Fundamentals for PV Activities, frequencies, actors
O&M-related Characteristics of PV • Modules: high reliability lasting 20 years or more • O&M Costs • Non-tracking: $12/kW/yr or .17% of capital cost • Single-axis tracking: .35% of capital cost • $40/kW/yr including inverter replacement • Planned maintenance: 0.04-0.08% of initial cost per year • Unplanned maintenance: 0.01-0.22% of initial cost per year • Most panels protected by tempered glass • Cleaning is possible and can be elected depending on site conditions • Most rely on rain to keep panels clean
O&M Tasks for Site Staff: Ongoing • Observe inverter front panel indicators when sun is up – generating power? Typical of conditions? Sudden changes? • Maintain log of cumulative energy delivery (kWh to date) and chart against the date. • Document all O&M activities in workbook available to all service personnel.
O&M Tasks for Site Staff: Annually • Walkthrough arrays for panel and racking damage. Report for warranty replacement. • Check position of disconnect switches. • Inspect/maintain wiring, insulation, protective materials. • Check tightness of mounting clamps. Reinstall loose modules. • Check for shading (new objects, vegetation) and remove. Remove debris from behind collectors and from gutters. • Clean modules with water or mild dishwashing detergent – no brushes, solvents, abrasives, harsh detergents. • Check hardware for corrosion, remove rust, repaint as needed. • Check inside combiner boxes for blown fuses and loose connections. Infrared camera useful for checking connections. • Check for signs of intrusion by pests: insects, rodents. Remove nests from electrical boxes or proximity of array.
O&M Tasks for Solar or O&M Contractor At intervals according to site conditions • Take simultaneous readings to compare balance-of-system efficiency with original efficiency of system as function of • Incident sunlight • Temperature • Energy output • Replace air filters on air-cooled equip. such as inverter • Retorque all electrical connections • Replace corroded electrical boxes • Repair / replace damaged to racks and modules • Replace failed fuses and other components • Install upgrades to inverter firmware and that of data acquisition and monitoring systems.
Unscheduled Maintenance: component failure • Complete systems: often warranted by installer for one year • Modules (rare, 6% of unscheduled maintenance costs) • theft / vandalism • 20 or 25 year warranty typical • Inverters (more common, 59% of unscheduled maintenance costs) • Much lower than any other type generator • Recent models much more reliable • 10 year warranty now typical
Step 5: O&M– Outputs Photo from Henry Price, NREL 14952 • Ensure responsible party carries out O&M/R&R* • Measuring and tracking success • Correlation with business plan and strategic energy plan • Contract compliance • Reporting of generation Met or exceeded energy and financial performance *Esp. if owner