As more inverter and storage companies partner on integrated devices for solar, installation doesn’t have to be complicated. The sonnenBatterie—a fully-integrated unit equipped with an inverter, lithium ion batteries, a 200-A automatic transfer switch and associated wiring and cabling—is a plug-and-play solution that’s quick to install. Similar devices can be installed comparably, but what follows is a guide to installing sonnen’s energy storage system.
First, it’s recommended that an appropriately sized service disconnect be installed between the main AC panel and the grid input terminals of the sonnenBatterie. Whole house backup using the sonnenBatterie is possible, however, a protected loads panel application will be used for the installation process.
AC Connections
There are no special tools required for installation. The sonnenBatterie provides a 240-V output to its microgrid. A 50-A breaker is placed in the main panel and the conductors run via conduit to the grid terminals inside the sonnenBatterie. Loads terminals connect to another 50-A breaker in the protected loads panel.
AC source connections
A 12-kW generator (no larger) can be connected directly to the generator terminals inside the sonnenBatterie. Existing or newly installed solar inverters can be AC coupled to the sonnenBatterie by placing the associated breaker into the protected loads panel. In an existing PV installation, the PV breaker on the main must be shifted to the protected loads panel. In this configuration, the PV will directly power the loads and any excess will charge the battery. When grid-tied, excess PV will backfeed to the grid.
DC connections
Since the sonnenBatterie uses lithium ion battery modules, there is no need to install a battery room ventilation fan, electrolyte circulation pump or even battery containment. There is also no need for specific gravity checks since the battery health and status is measured by software. Batteries connect in parallel using premade busbars, and building management system (BMS) cabling attaches to each battery in a daisy chain. The most important safety feature of the sonnenBatterie is the orange safety plug that is inserted into each 2-kWh battery module; the safety plug ensures there is no danger of electrical shock by the batteries even if the positive and negative terminals are shorted out by a dropped wrench.
Internet ready
A standard Ethernet connection to the sonnenBatterie allows for updates to be sent to the sonnen portal. From the portal (or sonnen app), customers and installers can keep tabs on systems and see performance and other service data. Software updates are automatically pushed to the system.
The sonnenBatterie has the ability to tie into local weather websites to balance charge and discharge behavior of the batteries based on a three-day forecast. If the weather will be bad for PV production, the sonnenBatterie will not allow the batteries to discharge as deeply since the storage will be needed for later use.
Smart plugs
sonnenBatterie uses Z wave controlled smart plugs that can be turned on automatically so excess PV can be consumed by loads instead of just backfed into the grid. This could be useful for zero export limitations. The plugs can also be configured to act as load shedding devices to turn off loads and extend the battery capacity for extended outages.