IN Brief:
- Polarium and inexogy will connect more than 1,600 distributed German battery systems through intelligent metering infrastructure.
- The architecture allows storage capacity to be divided between local resilience, trading, and grid services.
- The partnership can scale towards 10,000 systems as Germany continues its statutory smart meter rollout.
Polarium is working with German metering specialist inexogy to connect more than 1,600 distributed battery storage systems through intelligent metering infrastructure, turning an existing fleet of behind-the-meter assets into a controllable virtual power plant.
The first phase will use Germany’s intelligent metering systems, or iMSys, to provide the measurement and control layer needed for market participation. Polarium says the programme is intended to scale towards as many as 10,000 systems nationwide, moving the fleet from individually managed backup capacity towards a distributed resource that can support several commercial and grid functions.
The collaboration is structured as a long-term operational partnership. Binding service level agreements cover meter replacement and commissioning through 2029, while switching times will vary according to the processes of the relevant distribution system operator. Financial terms have not been disclosed.
Polarium describes the operating model as capacity slicing. Rather than committing an entire battery to a single use, available capacity can be divided between local resilience, trading, and grid services. That matters for assets installed at telecom and commercial sites, where backup power remains the first obligation but unused capacity can otherwise sit idle for most of the year.
The metering layer is what makes that division commercially usable. Real-time dispatch without reliable measurement does not create a settlement-ready flexibility product, and Germany’s distribution system is fragmented across hundreds of regional operators with different processes and timelines. The programme therefore depends on repeated metering, communications, commissioning, and data handling rather than simply adding more batteries to a software dashboard.
Polarium already has a commercial route for part of the same distributed fleet. In April, the company agreed a multi-asset tolling arrangement with RWE covering more than 1,600 batteries. From late 2026, RWE is expected to optimise at least 50MW of power and 135MWh of energy from those systems, with the portfolio targeted to grow towards around 300MW, 810MWh, and more than 10,000 batteries.
The inexogy agreement addresses the infrastructure needed to make that aggregation dependable. RWE’s role is market optimisation; inexogy’s is to support compliant measurement and connectivity. Bringing those functions together creates the route from a battery installed for local resilience to one that can be dispatched, measured, and settled as part of a wider flexibility portfolio.
Germany’s smart meter rollout remains central to that route. Bundesnetzagentur data for 30 June 2026 show 3.17 million intelligent metering systems installed across 54.1 million metering locations, equivalent to 5.9% of the total. Within the mandatory rollout category covering customers using between 6,000kWh and 100,000kWh a year, together with controllable loads under Section 14a of the Energy Industry Act, penetration had reached 26.1%.
The regulator has also stressed that installation alone is not enough. Intelligent meters must reliably capture and transmit quarter-hourly values before they can provide the technical basis for more dynamic tariffs and more efficient network control. For a distributed battery fleet, that same requirement applies to commercial flexibility: metering that cannot consistently support data transfer and settlement limits the value of otherwise responsive storage.
Low-voltage networks are one potential beneficiary. Distributed batteries can alter when sites import or export electricity, reducing local peaks or making spare capacity available at times of constraint. They cannot replace reinforcement where cables or transformers are fundamentally undersized, but coordinated storage can change the timing of power flows and defer some stress on equipment that would otherwise experience sharper peaks.
The control problem becomes more complex when backup obligations remain in place. A telecom battery may need to preserve a minimum state of charge for resilience while allowing a separate portion of capacity to respond to market signals. The platform has to account for state of charge, site reserve requirements, communications availability, market commitments, and network conditions at the same time.
That makes the first 1,600 systems a test of operational repeatability as much as storage capacity. Each additional site introduces another meter, communications path, distribution operator interface, and commissioning process. Scaling to 10,000 systems will depend on how far those processes can be standardised without losing the local requirements that determine whether an individual installation can actually participate.
The battery hardware is therefore only one layer of the project. Polarium and inexogy are attempting to industrialise the connection between distributed storage and the electricity market, using smart metering to turn dispersed backup assets into a measurable, controllable portfolio. If the model scales as planned, the value will come from coordinating thousands of small systems reliably enough that the market can treat them as one flexible resource.
