A new performance index for PV system analysis

Conference · Sat Dec 31 04:00:00 EST 1994

OSTI ID:208239

Townsend, T; Whitaker, C ^[1]; Farmer, B ^[2]; Wenger, H ^[3]

---

1. Endecon Engineering, San Ramon, CA (United States)
2. Pacific Gas and Electric Co., San Ramon, CA (United States)
3. Pacific Energy Group, Walnut Creek, CA (United States)

This paper describes a term called the Performance Index (PI) for analyzing photovoltaic (PV) system performance. The PI is the dimensionless ratio of actual to expected generation over any time interval. PV system performance is often described by applying terms widely used for conventional power plants. However, there are drawbacks to using some of the most common quantities, such as capacity factor, efficiency, and availability. For PV systems, these quantities exhibit wider seasonal variations and smaller magnitudes than for conventional power plants. Consequently, PV systems are often judged to be operating poorly, even in the absence of failures. At PVUSA, the PI is now being used for both real-time power plant monitoring and for longer-term analyses. A description of the calculation procedures and sample results are included.

• OSTI ID: 208239
• Report Number(s): CONF-941203--; ISBN 0-7803-1459-X
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
CALCULATION METHODS
COMPUTERIZED CONTROL SYSTEMS
DISPERSED STORAGE AND GENERATION
ENERGY LOSSES
MONITORING
PERFORMANCE
PHOTOVOLTAIC POWER SUPPLIES
POWER RANGE 10-100 KW
POWER RANGE 100-1000 KW
SYSTEMS ANALYSIS
WEATHER