GridTools is a software and hardware solution for monitoring, modeling, data-logging, and control of large-scale 3-phase or single-phase grid-connected PV applications.  The kit includes a DC side data-acquisition device (SystemDataBoard), AC side digital power meter (APN), LAN/DSL compatible static IP address remote data node (Vlinx ESP902), necessary site hardware, and GridTools software.   Ground up design approach has allowed complete specialization for PV applications. Significantly lower installation costs than competing alternatives with less functionality.   Custom hardware and software modifications possible.   Avoids interfacing with an inverter, where changing firmware and inaccurate data values make this reliance undesirable.

Live System Website, San Diego, CA

Many Useful Data Outputs are Logged:

• DC side: Array Volts, Array Amps.

• AC side: Phase A, B, C: Volts, Amps, Frequency, Power Factor, kW, kWh and Total for 3 phases: kVA, kVAh, Power Factor, kW, and kWh.

• Solar Irradiation: Used to calculate theoretical array output under environmental conditions.

• Temperatures: Array temperature, Ambient temperature.

• Computed: Sun position, Theoretical Array Output.

• Sandia PV Model used to calculate theoretical array output.

• Model uses measured solar irradiation and calculated sun position and array design and orientation.

• Model outputs max power point voltage, power at max power point, operating point max power and relative performance index.

• Inverter performance also calculated (DC to AC conversion efficiency).

DC Side Data Acquisition Device (SystemDataBoard) Specifically Designed for Standalone and Grid-tied PV Applications Includes:

• 12-bit accuracy on 11 channels.

• 2 DC amps channels configurable to measure any DC shunt (50mV or 100mV); 5A to 3,000A.

• Solar irradiation using small PV module (5-10W nominal, or LiCor).

• Solar irradiation sensor temperature (3 remote sensors included).

• 2 PV array temperature channels.

• Ambient temperature.

• 2 DC voltage channels.

• Spare 0-5VDC channel.

• Barometric pressure.

• 3 digital inputs.

• 2 digital outputs with software control.

• The SDB handles primarily the DC side data acquisition and the APN the AC side data acquisition, effectively bracketing any inverter in use.  

AC Power Meter (APN) Includes Digital Accuracy:

• 120-600VAC, single or 3-phase.

• Phase A, B, C: RMS VAC, RMS AAC, kVA, Power Factor, kW, Frequency.

• 3-Phase Total: kVA, Power Factor, kW, kVAh, kWh.

Designed For Remote Installations (using Vlinx ESP902):

• The Vlinx ESP902 is a remote data communication device addressable at any configurable IP address on the internet or LAN.

• Your office based GridTools PC can communicate with any number of  remote Vlinx ESP902's, using the IP address and access password.  

• GridTools software automatically publishes an HTML website for each system, including chart images, reports, text, and desired links.

• Maui Solar Energy Software can also host your system software and publish your system website.

Additional Software Features:

• One PC can be used to monitor and control many discrete PV systems using the GridTools software. 

• The number of systems monitored is limited by bandwidth and processing speed. Each discrete system requires 1 SDB, 1 APN, and 1 Vlinx respectively. 

• Reads the data acquisition hardware 1 time per second and calculates GUI updates. All data averages and calculated values are logged to database at 5 second (optional), 1 minute, 1 hour, and 1 day intervals.

• The user has an interface to specify the system design including location, module type, module orientation and tracking.

• The software then models the array output based on the sophisticated Sandia PV Model. As a result the software is constantly computing a performance index indicating whether the array is performing to expectations based in environmental conditions. Environmental conditions include sun position (spectrum), angle of incidence, array temperature, and irradiation. Also, the modeled Max Power Point Voltage is calculated and compared to operating voltage of the array, along with numerous corollary values.

• Sandia Photovoltaic Model can be used to accurately calculate PV module outputs under any environmental conditions.

• User must select array modules from database and construct series and parallel configuration of the array.

• Model inputs include total broadband irradiation, module temperature, sun position, and angle of incidence.

• Actual output of system can now be compared to modeled output.

• Relative performance index is computed.

• Troubleshooting can include or exclude array based on performance index.

Complete Kit Cost: $2,950 per system - Includes full installation support.

Software will monitor multiple systems (10-50) depending on computer speed and internet connection.

Call 808-298-9181 for more information or e-mail GridTools@mauisolarsoftware.com.

Qualitative Benefits Include:

• Documentation of energy output for customer, installer, public in general.
• Assurance system is performing to specification.
• Indication of production shortcomings, and prevention of further loss.
• Information for troubleshooting system and optimizing output.
• Site visits not required for detailed system analysis.