In the global energy storage landscape, obtaining the first official certification of a grid-connected inverter combined with sodium ion batteries marks a milestone. The result achieved by the Heiwit team represents not only a technological breakthrough, but also a system validation that opens up new opportunities for the integration of renewables and the decarbonisation of electricity grids.
Why certification of a grid-connected inverter is crucial
In the electrochemical storage sector, the certification of inverters for grid connection according to standards such as CEI 0-21 (low voltage) or CEI 0-16 (medium voltage) is an essential prerequisite for ensuring safety, reliability and full interoperability with grid operators. Until now, official certification was reserved exclusively for systems based on lithium or lead batteries. Sodium-ion batteries, although already used in pilot projects, had not yet passed the complex testing and validation procedure required by certification bodies.
Heiwit has successfully tackled this process by developing a solution that combines state-of-the-art sodium ion batteries with an industrial-grade three-phase inverter, optimised to handle the voltage and current characteristics typical of sodium.
Certification Stages: Testing, Testing and Compliance
The route to certification involved extensive testing of:
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Electromagnetic compatibility (EMC)
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Response to network commands (e.g. anti-islanding, frequency/voltage adjustment)
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Electrical safety and energy efficiency
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BMS-inverter interfacing, with active sodium cell monitoring and management
One of the most challenging aspects was the calibration of voltage and current limits, as sodium ion batteries have different charge and discharge curves compared to lithium. This required firmware customisation on the inverter and the development of new balancing strategies, CAN communication and integrated protection algorithms.
A record that opens up new markets
The achievement of the first grid-connected certification for sodium places Heiwit as an international “first mover”. The potential is huge: sodium-ion systems are inherently safer (no thermal hazard, non-flammable), sustainable (no lithium and cobalt), and promise lower costs with more abundant raw materials. With certification, they can now be installed in incentivised plants, energy communities and utility-scale projects with full regulatory compliance.
Heiwit continues to invest in research and development to push the boundaries of innovation and offer truly disruptive solutions in the storage sector. With this milestone, a new era opens for sodium ion batteries in Europe and worldwide.
La conformità alla CEI 0-21 riguarda l’insieme inverter più accumulo, non il singolo componente: nella gamma Heiwit agli ioni di sodio trovi i modelli pensati per lavorare in coppia con gli inverter ibridi.
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