Monitoring and Instrumentation

Managed by Sandia National Laboratories and the National Renewable Energy Laboratory (NREL), the RTCs are predicated on technical excellence. To ensure consistency across the five RTC sites, the RTC team has designed state-of the-art monitoring and data-acquisition systems. In addition, each site has an identically configured meteorological station (see details below.)

With these systems, the RTCs can predict and verify the power output of a PV or CPV system (based on the technology as well as the climate in which it is tested) and provide the data a manufacturer needs to affirm performance.

RTC Monitoring System

DC Electrical

  • Current shunts to measure the DC current of each string.
  • Resistive voltage divider to measure DC voltage of each system.

AC Electrical

  • Active, Reactive, and Apparent AC Power
  • Power Factor
  • Frequency
  • Line-to-line and line-to neutral voltage for all three phases
  • Line currents for all three phases and neutral

Temperature Measurments

  • Thermocouples measure back-of-module temperatures (OMEGA SA1)

Plane-of-array irradiance sensors

  • Pyronameter
  • Reference Cells
Basic RTC Monitoring Equipment
Current transducersCR Magnetics Model 189
Power meterElectro Industries, model: Shark100T–60-10-V4-D2-485P-DIN
ThermocouplesOMEGA SA1
PyranometerKipp & Zonen, CMP11
Reference irradiance sensorsEETS Model RC

RTC Meteorological Station

RTC Met Station Instrumentation
10-meter towerAluma Tower Co, Inc.
Irradiance SensorsDirect NormalGlobal horizontalDiffuse horizontalKipp & ZonenKipp & ZonenEppleyCMP 22CHP 18-48
PS Solar TrackerKipp & ZonenSOLYS 2
Barometric Pressure SensorVaisalaPTB110 or CS106
AnemometerRM Young03002-L
Humidity and temperatureVaisalaHMP60-L
Rain gaugeMet One Instruments370/375
Data loggerCampbell ScientificCR1000-XT-SW-NC

The data transfer process is described in the following SAND Report: The Regional Test Center Data Transfer System (556836 downloads)