Solar Self-Consumption: The Virtual Battery (2026 Installer Guide)

Understanding the Virtual Battery for Your Solar Self-Consumption

The principle: storing your solar surplus “on the grid” rather than at home

A virtual battery is really just an accounting mechanism. Your client’s solar system injects the solar surplus into the grid. Their supplier converts it into an energy credit, like a meter running “backwards.” Nothing is physically stored at the client’s home. The grid acts as the buffer, and everything depends on the contract’s rules.

What you actually get back: credited kWh, conditions, limits

You get back credited kWh when you consume later, in the evening or during winter. In practice, the credit mainly offsets the energy portion of the bill. Standing charges, grid fees and taxes remain payable. Depending on the offer, there may be an expiry date, an annual cap, or a loss of the balance if the client switches supplier.

The key differences with a physical battery and with full resale

With a physical battery, the client gains local autonomy, but pays for the hardware, its efficiency losses, and eventual replacement. With a virtual battery, there’s no extra installation work, but the client depends on the supplier and gets no backup during an outage. With full resale, the client sells all the production and buys back all their consumption.

Solar + Virtual Battery: When It Makes Sense in 2026

Winning site profiles: all-electric homes, heat pumps, EVs, shifted consumption

The virtual battery becomes worthwhile when your client has high, regular electricity use. Typically an all-electric home, a heat pump, a controlled water heater, or an electric vehicle. Solar produces a lot during the day. If usage can be shifted, or if the household also consumes in the evening, virtual storage helps make the most of the surplus injected and later “recovered” under the contract.

What can limit profitability: low surplus, shading, oversized capacity

If the surplus is small, the virtual battery does little. Same if the roof is shaded, or if the PV capacity is oversized relative to actual needs. Also watch out for subscription fees, the commitment period, and the metering rules. The gain often depends on the level of self-consumption and the purchase price of the kWh.

Ballpark figures to check on-site: annual consumption, base load, capacity, orientation

On-site, start from the bills and the hourly load profile. Note the annual consumption, the base load, the subscribed power, then the orientation and any nearby obstructions. Also check the available roof space in kWp and the fit between solar production, shiftable usage, and occupancy patterns. For more detail, see the guidelines for sizing a self-consumption system.

Choosing a Virtual Battery Offer: What to Check Before Signing

Fees and clauses: subscription, management fees, commitment period, caps

Before shifting your client’s solar surplus into a virtual battery, look at the total price. Check the monthly subscription, activation fees, management fees, and options that are sometimes charged separately (app access, data export). Check the commitment period, the cancellation terms, and the caps on credited kWh. Beyond that, some contracts cap or re-bill the surplus.

Compensation rules: credit validity period, seasonality, meter reading

Ask how the compensation is calculated. An injected kWh isn’t always a recoverable kWh. Check the credit validity period (monthly, annual), how seasonality is handled (generous in summer, tighter in winter), and the meter-reading frequency. Depending on the operator, Linky data can arrive with a delay that pushes back when credits become usable.

Technical compatibility: Linky meter, inverter, production and injection monitoring

On the technical side, confirm that the Linky meter is properly configured to measure both draw and injection. Check inverter compatibility and the communication gateway, and the quality of the monitoring. A good dashboard should separate production, self-consumption, and injection — otherwise you’re flying blind. To go further on using data from communicating meters, see using the data.

Field Method for Sizing a Solar System with a Virtual Battery

Data-gathering step: consumption history, usage, evolution scenarios (heat pump, EV)

Start with 12 months of consumption data (Linky, bills). Identify the morning and evening peaks, and the major daytime loads. Note which appliances are shiftable (water heater, washing machine) and which aren’t. Add a clear scenario if a heat pump or an EV charging point is coming. Solar sizing often hinges on this step.

PV sizing: aim for a good self-consumption rate without oversizing

Aim first for the daytime consumption share. An oversized system injects a lot, and the “virtual battery” doesn’t always offset the cost. Work from a realistic assumption of sunlight, orientation, shading, and a monthly curve. Adjust the capacity to cover a steady base, then manage the usage.

Planning commissioning: procedures, connection, settings, injection control

Plan ahead for the town-hall declaration, then the connection and the self-consumption agreement with the grid operator. At start-up, check the inverter setting, the metering, and any injection limits if required. Monitoring the first few days avoids surprises.

Securing Your Job: Regulations, Warranties and Best Practices

Administrative framework: self-consumption with injection, agreement, responsibilities

For solar, self-consumption with injection requires an Enedis agreement and a complete declaration of the system. The client remains responsible for the grid-access contract and the choice of how to sell the surplus. On your side, clarifying who does what avoids blockages. The file, timelines, contacts, and commissioning should all be written into the quote from the start.

Contracts, insurance, warranties: ten-year guarantee, equipment, electrical compliance

A detailed quote protects everyone. Check that your ten-year guarantee (garantie décennale) covers photovoltaic work. On the equipment side, distinguish between the product warranty and the performance warranty. For safety, plan for the inspections and the electrical compliance certificate when required, with diagrams and the location of the cut-off devices.

Client education: explaining the limits simply and avoiding overpromising

Make realistic promises. Production, savings, and payback depend on orientation, shading, and habits. Be clear about what’s included. Explain the simple points: daytime consumption, monitoring, maintenance. A well-informed client makes for a smoother job.