For Greater Independence and Reduced Electricity Costs: Sunny Island 3.0/4.4M

SMA Product Manager Ralf Rietze has assisted with the introduction of the new Sunny Island. In an interview, he introduces us to the new addition to the battery inverter portfolio.

The new Sunny Island 3.0/4.4M is suitable for grid-connected systems to reduce electricity costs and for use in remote regions with no grid connection. What exactly does that mean?

The new Sunny Island battery inverter can be installed in both self-sufficient off-grid systems, i.e., off-grid as well as in grid-connected applications with an existing utility grid (on-grid). In off-grid applications, the Sunny Island in combination with a battery forms the core of an autonomous electricity supply and, in addition to the integration of PV systems, also makes it possible to control other energy sources such as diesel generators, water or wind turbines. Off-grid hybrid systems of this kind are typical of rural regions without electricity supply. When used as a solution in a grid-connected area, the Sunny Island provides the link between a utility grid and the battery. Intelligent and automated management maximizes self-generated PV electricity for self-consumption so that less electricity is obtained from the utility grid. The devices can therefore be used for both applications. The only differences relate to the accessories required and the configuration of the devices.

With regard to grid connection, how can I use Sunny Island in my own home?

Example of a single-phase on-grid system

Just like the larger Sunny Island 6.0H/8.0H, the new Sunny Island can be incorporated as a core component into the SMA Flexible Storage System, the variable SMA storage solution in the SMA Smart Home. The SMA Flexible Storage System is the key to making your own energy transition and putting a stop to high electricity costs. Together with the battery-storage system and PV system, the new Sunny Island 3.0/4.4 make it possible to meet over 80% of annual electricity demand through solar power from your own roof. The surplus energy not used during the daytime is stored in the battery and is available to cover energy needs during the night. The Sunny Home Manager provides grid-optimized charging, meaning it minimizes, for example, derating losses resulting from any restriction on feeding into the grid. In addition, it enables intelligent and automatic load management. Assessment of results is possible via the Sunny Portal at any time, allowing customers to closely monitor energy flows.

The table shows which Sunny Island, battery storage capacity and PV system size are appropriate depending on the annual power consumption level (kWh).

The SMA Flexible Storage System can be optionally installed with a battery-backup function, so that even in case of a power outage, the solar energy currently being generated and stored can be used. With sufficient solar irradiation, a permanent electricity supply is ensured almost without restrictions. The customer has flexibility here in the choice of battery storage system, PV system size, PV inverter and battery inverter. In addition to the battery type (lead or Li-ion), the battery manufacturer and the battery capacity can also be designated. This ensures that a suitable replacement battery will be always available in the future. The product safety of the Sunny Island is confirmed by the “Certified safety” seal of approval from an independent certification body.

How can I use the Sunny Island in the off-grid area?

“Off-grid” it is mainly used in places where there is no access to the utility grid. In these regions, it helps to build a stable and reliable stand-alone grid. The PV system operators benefit from great variety and flexibility in terms of power and the merging of different energy sources to form an off-grid hybrid system. In this way, the system can be precisely tailored to customer needs to ensure that locally available and economical energy sources are always the ones used. As a stand-alone grid manager in off-grid applications, the Sunny Island will safely control all energy sources incorporated within the stand-alone grid. It can, for example, automatically start and stop a diesel generator if required by the connected load or the battery state of charge (SOC). The figure shows a single-phase Sunny Island system, which, in addition to the PV system, integrates a wind turbine, a diesel generator and a direct current charge controller (Sunny Island Charger). In the off-grid area, the new battery inverters stand up particularly well as a result of their robust design and excellent overload capacity. The high degree of protection IP54 and wide temperature range ensure that it operates continuously and reliably even in harsh ambient conditions. The sophisticated battery management system also ensures a long battery life, which ultimately has a positive effect on the operating costs of the entire system.

Example of the selection of Sunny Island for single-phase off-grid systems

Example of the selection of Sunny Island for three-phase off-grid systems

Your conclusion as a product manager: What is special about the new Sunny Island, and why should potential PV system operators choose it?

The new Sunny Island 3.0/4.4 are designed for low power ratings of up to 4.4 kW for single-phase and 13 kW for three-phase systems: This means that they offer perfect solutions for various applications in the lower power range. Sunny Island also provides customers with the maximum level of flexibility. Firstly, the battery size, battery manufacturer and battery type (Li-ion or lead) are freely selectable. Secondly, the battery storage system is suitable for both new and existing PV systems; the existing systems can also include external inverters. Thirdly, sophisticated battery management ensures a long battery life and reliable operation. The design of the PV system sizes and installation as either a single- or three-phase system are an advantage for both on- and off-grid operation. Irrespective of whether the Sunny Island is used to optimize the independent electricity supply in the user’s own home or for off-grid applications, with the Sunny Island, customers get a reliable and future-proof complete solution—and all tailored specifically to their installation design.

Thanks a lot, Ralf, for the answers.

More information

The new Sunny Island 3.0/4.4M have been available for delivery since mid-November 2014. For more information, visit our website.