Solar Power Storage

The Battery to Power your Home

Helped by Akkodis, Solar energy specialist SENEC is spreading its wings. The Leipzig-based company is expanding outside Germany, in Europe and beyond, as well as increasing and updating its portfolio of energy storage solutions for homes. SENEC has been developing sustainable energy solutions that bring together solar panels, energy storage and electric vehicle (EV) charging stations since 2009.

Around 75,000 SENEC storage systems are currently in operation across Germany. That number is expected to increase sharply, not least due to the energy crisis, which is highlighting the advantages for homeowners of producing and consuming their own energy.


More than a Battery

The centerpiece of the SENEC portfolio is the SENEC.Home energy storage box. The newest version, SENEC.Home 4, can store up to 25.2 kWh. But a battery is not just a battery, and it’s not only defined by its storage capacity. To deliver value to the customer it must fit in with other systems and infrastructures, such as billing software, installation and maintenance systems, backends, databases and much more.

Since 2019, Akkodis Germany has been developing a large part of the software to do that job–with around 45 consultants engaged in various SENEC projects, it’s one of the largest commitments in the Akkodis Germany portfolio.

The Akkodis solar power platform team is working on the newest version of the energy storage system, the Home 4, as well as on its predecessor, the Home 3, and on various other connected devices and services including software to configure the storage unit or the solar panels and wall box for charging an EV. The system has to be configured for connection to the energy grid. And the companies selling and installing the system have their own web interface including technical information and calculation tools too.


Beginning with Billing

It all began, back in 2019, with billing. EnBW, Germany’s third-largest energy company, had acquired SENEC the year before and hired Akkodis to help migrate to the EnBW billing system, named PowerCloud.

That accomplished, the team began updating the web portal used by the more than 1,200 installers selling and setting up SENEC products. The PIP (Partner Installer Portal) helps installers find the right solution for the customer, based on factors including, for example, the energy needs of the household and the position of the solar panels on the roof. The new PIP is making life easier for installers, for instance allowing them to configure the storage unit via the cloud instead of connecting directly to the unit via cable. The PIP is designed with modern technology, including the latest Angular software tools.


Splitting the Monolith

The next task was to modernize and scale the backend of the system. Sven Thiergen, Senior Backend Developer covering backend business logic, database handling, real-time message processing and cloud deployments, took a key role.

“The old version had been built as a monolith and was reaching its limit and starting to get into problems to scale,” he says.

The solution was to split the monolith into sub-parts and deploy a microservices architecture instead, with new additions and features as microservices in Kubernetes.

“With a modern cloud approach, the backend is now ready to handle much more data than before,” Thiergen says.

Real-time Communication

Describing the technology, Thiergen and Hoffmann point to one important feature in the new, updated SENEC.Home 4 device: real-time communication.

While the embedded control system of the device currently transmits data every five minutes, the new version has switched to real-time communication, with Kafka as an event-streaming and central messaging platform. That makes the SENEC.Home 4 a truly real-time system and allows for much quicker control, supervision and prevention of issues such as battery overcharging or other factors that could affect performance and lifetime of the storage unit.

However, ensuring scalability is probably the most crucial contribution Akkodis has brought to SENEC. SENEC has grown to 500 employees in just three years, and is now expanding into Italy and Australia, both markets with specific requirements. Australian homeowners, for example, want to sell excess energy from their storage directly to their local energy grid. To do that, the system needs to support VPP (Virtual Power Plant), a software tool that bundles the output from small energy producers and sells it to grid operators.

In a few years’ time, instead of 75,000, there could be 500,000 or even a million storage units in private homes across the globe–thanks to the careful work of the Akkodis solar power platform team, that growth should come without scalability issues.