The automatic battery backup function introduced in January 2014 with Firmware Release 3.0 lays the foundation for maximum supply security. In the event of a power outage, it ensures nearly continuous power supply to all consumers, with an interruption of only five seconds. Even customers who have already installed a Sunny Island self-consumption system can use the new battery backup function, thanks to the possibility of retrofitting this new feature. The necessary firmware will be available for download.
After more than 10 years of practical experience with battery backup systems, SMA offers PV system operators the security of worry-free service. The Industrial Trade Association inspection certificate testifies to the system’s reliability, giving the installer maximum assurance that all current installation and safety standards have been met.
With Release 3.0, self-consumption and battery backup systems with Sunny Island can also be expanded into three phases. This makes the SI6.0H/SI8.0H suitable for a wide range of applications, including commercial. The extremely high-capacity backup system offers lasting protection against grid failures – a particular advantage for relatively small commercial entities, such as workshops or office buildings.
Self-consumption and power backup systems based on the Sunny Island 6.0H/8.0H offer high flexibility for system design, with useful configurations for all PV systems from 3 to 30 kWp.
What is my projected self-consumption level – and therefore my independence from conventional energy carriers? An important question for the PV system operator. The SMA Sunny Design software provides the answer, even during the consultation phase. The application calculates the self-consumption and self-sufficiency rates with precision, yielding reliable predictions of potential savings and cost reductions. With the online version of Sunny Design, determining these parameters is now even easier and more user-friendly.
Installers have two options for assembling the battery backup function: They can do it themselves, consulting the installation guide for details, or they can order the distribution board as a fully wired system.
Longer battery service life and therefore lower system costs are the clear advantages for PV system operators using the new seasonal battery operation, which can be activated with Release 3.0. The possibility of automatically reducing optimal self-consumption in winter keeps the battery charged at a high level during this season when irradiation is weaker. During long winter nights, most of the battery charge can be used as backup power, providing additional security for the system operator. The scenario in summer is exactly the opposite, self-consumption rises, and with it the self-sufficiency rate. In summer, when nights are shorter, only a small portion of the battery must be reserved for backup power.
Release 3.0 features other remarkable improvements in efficiency. For example, when the minimum state of charge is reached, functions that are no longer needed are turned off until the next opportunity to recharge with solar energy.
With Sunny Island systems, solar energy is always available when it's needed – even after sunset and when the sun is hiding behind clouds. Using its integrated energy management system, the Sunny Island automatically charges and discharges the connected battery. The PV inverter does not feed electricity into the utility grid until the battery is fully charged and the electricity needs of all electric devices in the household have been met.
Although the Sunny Island is only connected to one line conductor, it automatically manages the total power. The energy meters work in a cumulative manner, so that the power from the individual line conductors is added up. The Sunny Island can then always feed in or draw as much energy as is needed in accordance with the sum total of all phases.
External measurements confirm the system's extremely high efficiency, with a rate of 95.8 percent – and well over 90 percent even at a charging/discharging capacity of just 300 W. SMA is the only manufacturer in this field that currently allows fully external measurements of efficiency curves and also makes the results public. The overall efficiency curve of AC systems based on the Sunny Island is significantly higher than that of most DC-coupled systems.