Operations & Maintenance (O&M)
Project: Cliff Cottage
System Size: 50kWp
Summary Overview/Goals & Objectives/Result: Regensys was contacted regarding an existing installation with lower than expected production. Originally installed in 2010, the installer was no longer trading and therefore could not assist with the warranty issues. The owner first noticed the issue via online monitoring linked to the inverters, which showed low output and an error code. Regensys undertook a complete assessment of the array, which was poorly installed with insufficient space between panels. The results of the assessment were stark, 78 panels had failed! They suffered from water ingress and hotspots/flashing. Unfortunately, the original installer had chosen a very cheap Chinese brand; they had no UK presence and would not honour their warranty. Before replacing the panels—paid for by the client—we assessed the benefit of increasing the space between the panels and concluded the cost would be offset by the additional generation.
Future: We now regularly monitor and maintain the array to ensure peak performance.
Project: Bowldown Farm
System Size: 17kWp
Summary Overview/Goals & Objectives/Result: Regensys was originally asked to install an automated metering reading (AMR) solution for a portfolio of clients by the system installer. The objective was to provide collective meter reading services to clients through standard AMR meters where clients will have access to their meter reading via a simple centralised web-portal. Our AMR service provide a host of added benefits, the most prevalent of these being the capability to compare actual generation performance data with the PVGIS database with an aim to measure individual system performance giving early stage system diagnosis.
Our AMR system soon alerted us to suspicions under-performance issues with this installation running at 47% capacity degrading to around 42% in some cases. This identified some serious issues with the installation and we were asked to conduct a full investigation of the array and electrical installation. We found multiple issues across the array with water ingress and hotspots/flashing being the most prevalent. The panels were still under warranty and from an active supplier in the UK.
Future: We continue to monitor the array via the smart meter and recommended a total system re-build to ensure optimum performance of the installation. Within our monitoring package we set alerts which are triggered by performance tolerances; if the array performance dips below the predicted output based on weather data and past performance, we will automatically inform the client and either diagnose remotely or send an engineer to investigate.
System Size: 120 kWp
Summary Overview/Goals & Objectives/Result: Metering and monitoring of the array has demonstrated general performance exceeding expectations by between 5-10%.
Future: A review was carried out to extend the system capacity, subject to planning to bring the system more in line with the site demand and full export capacity. We have recommended to install an extended array in the same field and re-arranging the system architecture to make optimum use of the export capacity in peak summer months as well as connecting another main property not currently taking energy from this supply into the new distribution system. Interestingly, there is a limit imposed by the District Network Operator to not exceed 130kW peak back into the grid. Our proposal is to install an additional 50kWp array and ‘clip’ the maximum output by restricting the inverter design architecture such as to use the full export limit on peak generation days. This then allows the client to benefit from a much greater yield throughout the majority of the year while only sacrificing a small peak output on a few days of the year, at which point they will still be generating optimum capacity.