The Nivoli PV plant had many malfunctions, among which an inefficient monitoring system. The exhisting monitoring system was complex and employed a series of Siemens programmable logic controllers (PLCs) connected to centralized Nidec inverters and managed by a PC which collected data from the plant. This system entailed high maintenance costs, due to the expansive Siemens software licences, and was instable because the PC wasn’t able to function non-stop in a dusty environment where temperature and humidity leaps happen on a daily basis. Predictably, the PC stopped working. The employed software represents the second problem Higeco has solved. Although it was specifically designed for the Nivoli plant, the software lacked many of the fundamental features required from monitoring system, such as the alarm management. Therefore, due to the impossibility to have a real-time overview on the machines status and their problems, the number of plant stoppages increased greatly, causing a proportional economic loss.
In order to solve the problem, Higeco has installed a GWC 4DIN, which replaced the Siemens PLCs and was interfaced directly with all the centralized inverters. Higeco GWC was also able to acquire the relay protection (to control its real-time status) and connect to all the chillers and video cameras installed in the plant, allowing the user to manage the devices electric consumption in relation to solar radiation, inverter temperature and ambient temperature. In fact, thanks to Higeco Solar Advanced software, the user can integrate any device with a modbus communication protocol. Finally, Higeco created an efficient alarm management system, which ensures a real-time overview on malfunctions, allowing the user to intervene quiclky and to accurately diagnose the cause of the breakdowns.
The intervention has improved the situation on two levels. Firstly, the implementation of Higeco systems has both lead to important savings, thanks to the termination of the Siemens PLCs licences, and has allowed the user to know the real-time status of every plant device, decreasing the number and duration of maintenance interventions. Moreover, the efficient management of the air-conditioning functioning has greatly decreased its energy consumption. Secondly, the plant efficiency has been restored (PR 87%) and the downtime has been eliminated together with the cost of maintenance.
The estimated payback period of the revamping investment is about 8 weeks.