In this age of information, smart investors expect to stay informed regarding the performance of their investments. This is as true for the stock market as it is for PV systems. System owners want real-time, easy-access insight into their systems, visualization of energy performance, knowledge of system health, the ability to report and share their output, and of course to be able to easily calculate system revenue. As the industry moves towards more advanced functionality and greater connectivity of PV to the cloud and smart grid, inverters are increasingly able to meet these demands.
The inverter was originally named for its main function of AC-DC conversion, but its role has since expanded. Functioning as the brain of the PV system, advanced inverter solutions are now responsible for communications, monitoring, smart energy management, grid interaction, safety and more. But what is the brain without the entire nervous system working in tandem? Module-level power electronics (MLPE) create a network of control and intelligence operating behind the modules to provide module-level maximum power point tracking (MPPT), emergency shutdown, design flexibility, and insight into system health. MLPE devices, such as power optimisers, track module-, string-, and system-level data on system production enabling greater resolution into system performance. However, enabling remote access to the data is just as important as the data itself – and this is where the cloud comes in.
The first link in the communications chain is from the module to the inverter. For instance, with SolarEdge power optimisers, the communications from module to inverter is conducted via Power Line Communication (PLC), so no special wiring is required. However, the link from the inverter to the cloud can be more complicated. Typical communication strategies require installers to enter the premises for setup, and then for the system owner to maintain that connection through their router throughout the system’s lifetime. Both of these requirements can be troublesome.
Wifi, ZigBee, and newer cellular-based strategies eliminate the need to access the premises. Cellular-based communication solutions can also remove the requirement for the system owner to maintain connectivity and can be useful in locations without internet access or broadband infrastructure. With a GSM cellular kit, installers receive a GSM network card combined with a preinstalled SIM card, typically including a data plan. Such a cellular kit can be used with any single phase SolarEdge inverter, including SolarEdge’s StorEdge solutions to provide online battery monitoring and the SolarEdge revenue-grade inverters to provide an end-to-end revenue metering solution.
Once the connection is made, data can be uploaded and saved on cloud-based monitoring platforms and accessed through any device with internet connectivity. System owners and installers alike can see high-resolution system performance via computers, smartphones, or tablets.
With a reliable chain of communications from the inverter to the cloud, we unlock a suite of possible options. For example, by simply adding an electricity meter, system owners can watch their consumption patterns. When paired with a battery, system owners gain detailed insight into energy stored, consumed or fed in to the grid. With connectivity also comes control. Inverters can be upgraded and programed remotely rather than requiring an onsite visit. So even though we are an industry that is dependent on sunny days, it turns out that the cloud plays an important role in its advancement.
Lior Handelsman is vice-president marketing and product strategy at SolarEdge.