1. In France, solar value is moving toward self-consumption

France’s residential solar model has long been built around a familiar structure: the household consumes the electricity produced by its solar panels first, then sells the surplus injected into the grid under the obligation-to-purchase framework. This model still matters, but its center of gravity is shifting.

The S21 tariff framework was significantly revised in 2026. The new parameters published around June 2026 clearly push small-scale PV toward more direct self-consumption: the announced tariff for injected electricity is much lower than historical levels, and investment premium mechanisms have been reduced or removed in the new framework. For new projects concerned by these rules, surplus sale can no longer be treated as the main driver of solar economics.

This creates a new question for French homeowners: how can a home avoid selling low-value solar electricity that could be used locally at higher value? The answer comes down to three capabilities: store surplus energy, control power flows and see the full system clearly.

2. Why existing PV systems in France need a retrofit path

Many French households installed solar panels before considering a battery. This staged approach makes sense: produce first, observe household usage, then add storage when the value becomes clear. But when surplus injection loses value, the limits of older architectures become visible.

A strong solar storage system should not only answer “how many kWh can the battery store?” It should answer a more important question: how does the system decide where solar energy should go at each moment?

3. The bidirectional AC port: what makes storage genuinely useful

The TSUN MAU series is based on an AC-coupled architecture designed for retrofit. In a home that already has photovoltaic panels, AC-coupled storage can add a battery on the alternating-current side without replacing all panels or rebuilding the rooftop DC architecture.

The key differentiator is the bidirectional off-grid AC port. Unlike a traditional backup port that only powers a load during an outage, a bidirectional port can participate in everyday energy management. It can support critical loads, integrate existing solar generation, enable local PV expansion and help the system control power flows more precisely.

4. TSUN microinverter + MAU: from passive solar to controlled solar-storage

France already has many PV systems based on microinverters. For these homes, adding a battery should not mean replacing useful existing equipment. TSUN’s approach is to bring microinverters and the MAU battery into a shared communication and energy-management logic.

When a PV system equipped with TSUN microinverters is paired with a TSUN MAU battery, the goal is not simply to add storage capacity. The goal is to create a control loop: solar production, battery state of charge, household consumption, grid injection and EMS strategy work together.

For a homeowner who already has solar panels, this approach protects the original investment. The system no longer behaves like free generation followed by passive injection. It becomes a controlled residential solar system designed to raise self-consumption and reduce grid purchases during less favorable periods.

5. Dual metering and smart EMS: see clearly to save more

A solar self-consumption system cannot be optimized if data is fragmented. The homeowner needs to know how much the panels produce, how much the house consumes, how much the battery charges or discharges, and how much electricity is imported from or exported to the grid.

TSUN MAU is built around a multi-flow measurement logic. On the grid side, the system follows electricity exchange with the grid. On the PV side, it analyzes solar production. On the battery side, it monitors state of charge and available power. On the household side, it helps users understand energy behaviour. This visibility matters for French homes that want to optimize self-consumption with Linky, Enedis procedures, a solar battery and increasingly electrified household loads.

What the EMS should manage automatically

7. Checklist before adding an AC solar battery in France

A good solar battery is not selected only by capacity in kWh. It must match the PV system size, household consumption, injection contract, existing inverter type and the homeowner’s goals.