A real-world example of the smart integration of solar panels, thermal storage, and a battery system
Sodium-ion batteries in practical use: Insights from Benzenschwil
The energy transition is conceived at the national level, but its implementation takes place in individual buildings and neighborhoods. A striking example of this is the Synergieplus multigenerational house in Benzenschwil. The project aims to maximize the self-consumption of renewable energy and minimize the need for external energy supplies.
Even before the most recent expansion, the property had a high-performance infrastructure: a 144 kWp photovoltaic system generates most of the electricity needed, while a heat pump and a seasonal heat storage system ensure that excess summer heat can also be used during the cold season.
Despite this favorable starting point, a familiar challenge emerged, particularly during the transitional seasons and in the winter months: the time lag between energy production and energy consumption meant that part of the electricity demand still had to be met through the grid.
The Role of Battery Storage
To further increase self-consumption, a battery storage system based on sodium-ion technology was installed in April 2026. The system has a power output of 72 kW and a storage capacity of 108 kWh.
The purpose of the storage system is simple: excess solar energy is stored during the day and is then available when the photovoltaic system is producing little or no energy. This helps smooth out peaks in energy consumption and significantly reduce the amount of energy drawn from the grid.
The initial operational data clearly demonstrates the potential of this solution. While approximately 850 kWh of electricity still had to be drawn from the grid in March 2026, this figure dropped to just 8.8 kWh in April following the commissioning of the battery system. At the same time, the self-sufficiency rate increased from 62 to 99 percent.
These figures demonstrate the impact that a smart storage solution can have on the use of locally generated energy.
Why sodium-ion technology?
In addition to improving self-consumption, the owners of the multigenerational home also prioritized sustainability and safety when selecting storage technology. Sodium-ion batteries are considered a promising alternative to conventional lithium-ion systems in this context.
The key features of these sodium-ion batteries include:
- Avoiding critical raw materials such as lithium and cobalt
- High thermal stability and a high level of safety
- Good performance even with frequent charging and discharging cycles
- Reliable performance even at lower temperatures
This makes the technology particularly well-suited for stationary energy storage systems that are designed to operate reliably for many years.
Findings from the project
The Synergieplus example shows that high levels of energy self-sufficiency are already technically feasible today. The key factor here is not only storage capacity, but also the choice of the right technology.
By using sodium-ion batteries, the project is deliberately focusing on a sustainable alternative to conventional lithium-ion systems. The technology does not require lithium, cobalt, or other critical raw materials, thereby contributing to a more resource-efficient energy storage.
Safety was also a key factor in the choice of storage system. Sodium-ion batteries are considered a particularly safe solution for stationary applications and are designed for long-term use.
Synergieplus thus makes it clear that the energy transition is not merely a matter of energy production. Equally important are storage solutions that combine sustainability, safety, and security of supply.
A glimpse into the future
Projects like Synergieplus provide valuable practical experience for the next generation of energy systems. They demonstrate that a sustainable and largely independent energy supply is not just a vision, but can already be implemented today.
Interested parties can view the battery system on site. Synergieplus offers tours . Please contact inesco energy directly if you would like to learn more about sodium-ion storage systems:
Phone: +41 44 517 51 40
Email: beratung@inesco.energy