Solar Plants & Monitoring – Why?

Real-time monitoring of Solar Plants

Solar plants benefit their owners by producing power in line with expectations for the duration of the plant’s life. Typically, a plant’s life lasts about 25 years. If a solar plant is not monitored in real-time, it will be virtually impossible to know when it is not producing what it is supposed to.

Most solar plants either sit on a client’s roof. Alternatively, they may sit on some vacant land close to the client’s building. The solar plant produces electricity when the sun shines. This electricity is fed into the client’s building, supplementing energy from the grid or diesel generator.

Solar Irradiation

A solar plant produces power based on the level of solar irradiation it receives. Solar irradiation can be the ambient temperature or the module temperature. A solar plant will produce its rated capacity in kWp only under Standard Testing Conditions (STC). STC is 1000 W/m2 of irradiation, ambient temperature of 20 °C and module temperature of 25°C. If any of these variables differ from STC, the actual production of the solar plant can vary.

Other Factors Impacting a Solar Plant

  • Shading on panels
  • Dirt on panels
  • An oversizing of the solar system (ie if the load is smaller than the solar production and if grid-feedback is not allowed, then inverters throttle the solar plant)
  • Inverter de-rating due to extreme weather conditions
  • Inverters tripping due to grid power fluctuations
  • Stolen panels

Real-time Monitoring

With a proper real-time monitoring and control system on a solar plant, the actual production can be compared to expected production. Expected production can be calculated using the measured irradiation, ambient temperature and module temperature. When the actual production deviates from expected, this can be investigated to determine the cause of the problem. The problem can either be addressed via remote controls by changing or updating settings on the inverters. Alternatively, a technician can be deployed to site to remedy the problem. Most important to note is that the problem cannot be fixed unless it is identified first. This is where remote monitoring is critical.

Financial Returns

If a solar plant does not produce what it is expected to, the financial returns to the owner will be lower than expected. What is worse is that the owner might not even realise it until much later. This may result in further deterioration of components. Some component warranties can also be jeopardised if they are operated under strenuous conditions for long periods of time.

Issues Affecting Solar Plants

From our experience, a range of issues can affect solar plants and their expected production. They are typically large assets, spanning many thousand square meters. They have thousands of panels, many inverters, kilometres of cabling, and many parts and components. Any fault among these components can ultimately affect the energy produced. A solar plant works only as well as it is looked after and maintained. If a solar plant is not managed properly, it will not produce what it is supposed to. A solar plant owner cannot know that his plant is not operating efficiently without real-time monitoring and controls.

To ensure your renewable system is performing optimally, we offer management services to suit your facility’s needs and internal resources. In addition to our live in-house monitoring systems, we offer monthly reporting, monthly cleaning, rapid response and regular site inspections. With an NSE maintenance agreement in place, you are able to focus on your own work, with peace of mind that your facility is performing optimally all year round.