Planning For a Monitoring Retrofit
Retrofitting a legacy solar site with a new monitoring or control system can bring both uncertainty and risk to the daily operations and business reporting functions. Having performed hundreds of retrofits with our own Acuity platform, we've developed a guide for new customers to reduce the retrofit migration risk by supporting proper planning.
First, establish a baseline of what is and is not working on the site before planning a retrofit activity:
Make a list of all the Devices on site: Meters, Inverters, Trackers, Weather Station Sensors, Reclosers, etc.
For each one of these devices, record whether the device is currently communicating. In the event that the existing monitoring system is not functioning, or partially functioning, a technician may need to verify device communications locally from the field.
Also, for each device that should be monitored, record the method and configuration of the communications. Is the device network or serial chain connected? Does it have an IP address or use a MODBUS RTU device ID and baud rate configuration?
For serial connected devices, will the serial chain be moved to the new retrofitted system, or is there a business need to share communications between the existing system and new retrofit system for a period of time to allow for transition?
For devices that cannot be communicated with currently, is there a plan to address the root cause prior to or during the retrofit process? Examples may include repairing a serial chain, replacing network cables or switches, replacing inverter comms cards, replacing old weather station sensors.
Secondly, consider the condition of the existing monitoring equipment, even if functional:
Are the existing control cabinets in good condition, dry, and weather tight?
Do the existing power supplies have proper surge protection and wattage to support any additional retrofitted components (if not self-powered)?
Are the existing network switches in good working condition with functional spare ports to use for any new network connections.
Third, metering is critically important for performance analysis and revenue recognition business processes.
Ensuring that PT and CT ratio values are known.
A recent sample of power and energy series data is available to verify proper scaling and comparison when the transition is completed.
Fourth, determining how data will get from your site to you:
Is there an existing connection or cellular modem that can be used?
If cellular, who manages the data plan, and is it sufficient to support the retrofitted system?
If cellular, which cellular providers are supported in the area?
If a local connection (building or school network) is being used, are there any IT setup, security, or access coordination that need to be coordinated.
Finally, documenting some of the business specific requirements the retrofitted system will need to perform:
Which users will need access, and what permission levels should they have?
Are there any existing reports or data deliveries that need to be configured?
Are there any business systems or services that need to be integrated with to support business continuity?
Taking the time to perform a detailed facility and equipment survey, coupled with an evaluation of the access and roles the new system will be required to perform will help your retrofit project execute more smoothly and with fewer surprises.