The value of energy monitoring systems for solar PV

Rob Barker, Director of Power Quality Expert Ltd, has more than 25 years’ experience in electrical test and measurement. Here Rob considers the advantages of a single supervision system for prosumer photovoltaic PV storage and self-consumption.

solar installer using energy monitoring system

The prosumer approach to the integration of renewable energy sources and storage in buildings and the distribution grid creates a need for sophisticated control and monitoring systems to ensure efficient energy management and grid stability.

These systems provide real-time data and decision-making capabilities that empower building owners and operators to optimise energy consumption, reduce costs, and enhance resilience.

With the exponential uplift in solar PV installs, measurement and communication systems are becoming increasingly important. In the past, installations used to be planned according to the “fit and forget” principle and PV systems were connected to the grid in an uncontrolled manner.

Today, PV systems with active power management should be actively controlled based on the system conditions. Some controls such as feed-in limitation, dynamic voltage limitation or even frequency control can be implemented locally without communication. However, if the PV systems are integrated into the overall system and operated to optimise with the distribution and transmission grid, supervision systems are necessary.

Under supervision

Energy monitoring and management systems can create a complete supervision and management system for photovoltaic systems (including multi-site ones) which will allow for the continuous control and monitoring of each component (inverter, panels, strings, etc.) in order to avoid total or partial stops in energy production and, at the same time, allow the energy produced and/or used for an installations activities to be measured and managed.

Monitoring and management systems can act as a single controller of the various components of the systems, regardless of their type, allowing you to manage various functions.

A single supervision system can benefit photovoltaic, storage, and self-consumption since it will:

Optimise energy production: the system can track solar irradiance and other environmental factors to determine the optimal time to generate electricity. It can also adjust the inverter settings to maximise power output.

Manage energy storage: the system can track the state of charge of the storage system and optimise its use to meet energy needs. It can also switch between using grid power and stored energy to minimise energy costs.

Promote self-consumption: the system cananalyse energy consumption patterns and suggest ways to reduce reliance on grid power. It can also schedule energy-intensive appliances to run when solar power is available.

Track energy use and production to spot issues quickly and make smart choices

Keeping the PV system under control is essential for ensuring a high and constant return and to cover the cost of the investment in the shortest possible time. With energy monitoring and management systems, you can acquire instant and historical data including the energy used or exported into the electricity grid.

In order for the yield to be at its maximum and constant, the individual photovoltaic panels that make up the system must function correctly.

A faulty or unproductive panel compromises the correct functioning of the entire string and consequently the entire system. The causes can be many such as: dirty cells, shading or poor power quality.

Because PV inverters can affect power quality, it is recommended to monitor and measure for power quality disturbances, especially harmonics and imbalance.

Predictive maintenance and remote control

Energy monitoring and management systems allow you to exploit the benefits of predictive and/ or preventive maintenance of a production plant. Thanks to the continuous acquisition of data and the generation of appropriate notifications it is possible to manage the maintenance by knowing the real operating conditions of the system.

The planned maintenance is therefore no longer at regular intervals but based on the actual operating conditions and before the occurrence of faults, significantly reducing costs and repair schedules.

Interconnection and integration between devices (inverters, storage systems, etc.) and systems (heat pumps, electric vehicle charging stations) of any brand installed or part of a legacy system is possible in order to create a system that allows continuous control of the functioning of each component.

Intelligent and shared data management makes a significant difference in both efficiency and in operational and decision-making speed. It is essential that remote management and interconnection are achieved using connections and protocols based on documented, publicly available and internationally recognised specifications (Modbus RTU o TCP-IP, HTTP, MQTT, JSON, Web API, etc.).

The result is the creation of an integrated digital ecosystem that can be controlled remotely.

An IoE (Internet of Everything) digital platform allows you to control and manage systems and buildings by combining the aspects of monitoring and energy automation with the possibility of interacting in real time on different devices using the possibilities offered by IoT (Internet of Things) systems.

For example, in a grid-connected photovoltaic installation, a control system is needed to manage the flow of electricity between the solar panels, the storage system, and the grid. The control system should be able to do the following:

  • Limit PV production to prevent excess power from being sent to the grid.
  • Maintain a healthy power factor at the point of grid connection to avoid penalties.
  • Shift energy-intensive loads to the time of day when solar power is most abundant.
  • Be compliant for demand response programs, which require the system to reduce or increase energy consumption during certain times of the day. This can be effectively achieved using storage or multiple generation sources.

Simplifying installation

The installation of an effective monitoring and management system is greatly simplified by using a pre-configured kit that is designed for the task.

One such solution is the Electrex monitoring kit. Based on the Libra devices that are designed for photovoltaic systems, the Electrex represents the ‘plug & play’ solution and delivers advanced technology for monitoring and managing any component of the system:

  • Inverters, strings and storage
  • Low and medium voltage electrical loads
  • Power quality analysis
  • Direct current measurement
  • Environmental and process parameters.

Libra devices have internal, multiple modules that are configured based on the needs of the system, allowing a quick, simple and non-invasive installation.


With a correctly specified single device it is possible to record the energy produced, consumed and exchanged, as well as integrate the data of the inverters or any other device in order to control every single panel in order to optimise its performance.

Image credit: iStock, Power Quality Expert Ltd