A virtual battery is not a piece of equipment, it is a commercial offer from an electricity supplier: nothing is stored anywhere, the injected surplus becomes a line of kWh credit in the supply contract. Two consequences you have to set out on the quote. The credit only offsets the energy portion of the bill, never the grid fees or the taxes, and France’s national energy ombudsman puts those two items at close to two thirds of the price of a kWh, with excise duty alone at €30.62/MWh as of 31 August 2026. And taking up such an offer means giving up the purchase obligation, whose tariff the order of 1 June 2026 has now set at €0.011/kWh excluding tax: what is being given up has become small, which changes the trade-off without making it obvious.
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 an accounting mechanism, and nothing else. The system injects the solar surplus into the grid; the client’s electricity supplier converts it into an energy credit, like a meter running “backwards.” No equipment is installed, no plant room is needed, there is nothing to connect and nothing to maintain. Say so at the start of the appointment: the word battery suggests autonomy during an outage, and there is none. Everything rests on the clauses of the supply contract.
What you actually get back: credited kWh, conditions, limits
The client gets back credited kWh when he consumes later, in the evening or during winter. In practice, the credit only offsets the energy portion of the bill. Here, item by item, is what remains payable on a domestic low-voltage connection of 36 kVA or less, with the rates in force.
| Bill item | Cleared by the credit | Rate applicable at 31 August 2026 |
|---|---|---|
| Supply, energy portion | yes, up to the balance | contract price |
| TURPE, management component | no | €17.12/year, contract signed by the supplier |
| TURPE, withdrawal, capacity portion | no | €12.49/kVA/year, medium use |
| TURPE, withdrawal, energy portion | no | 7.21 / 3.84 / 1.66 / 1.14 c€/kWh across the four time bands |
| Excise duty on electricity | no | €30.62/MWh |
| CTA levy and VAT | no | per the schedule in force |
TURPE 7 HTA-BT schedule applicable from 1 August 2026, set by decision no. 2026-105 of France’s energy regulator of 21 May 2026. The reading to keep is one sentence from the national energy ombudsman: when the client consumes his credit, he pays the grid fees and the taxes, close to two thirds of the price. A credited kWh is therefore not worth a purchased kWh, and that is the first thing to put in writing if you present the offer.
Depending on the contract, add an expiry date on the balance, an annual cap on credited kWh, and forfeiture of the balance if the client switches supplier or moves house. None of those three clauses comes from any regulation: they are what the supplier chose to write, and they vary from one offer to the next.
The key differences with a physical battery and with full resale
A physical battery brings real local autonomy, at the price of the hardware, its round-trip efficiency and its replacement. The virtual kind requires no works, but creates a dependency on the supplier and offers nothing during an outage. With full resale, all the production is sold and all the consumption bought back. The three arrangements therefore do not compare on the same plane: the first is a works package, the second a contract clause, the third a valuation regime.
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 the 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.
The benchmark is easy to set, and it has changed a great deal. The order of 1 June 2026 removed the self-consumption premium and set a single feed-in tariff of €0.011/kWh excluding tax up to 100 kWp, indexed by 2% a year over a 20-year contract, with no payment for injection beyond 1,600 kWh/kWp/year. Put another way, 1,000 kWh injected over the year earn €11 excluding tax under the purchase obligation. That is the figure against which the virtual battery subscription has to be compared over twelve months. On installations commissioned before 5 June 2026, on the other hand, the earlier purchase contract stays in force and the trade-off has to be redone with its own tariff, often ten times higher.
On the tax side, only two things are settled. Article 35 ter of the French general tax code exempts from income tax the proceeds of an individual’s sale of solar electricity, on three cumulative conditions: a rating not exceeding 3 kWp, connection to the grid at no more than two points, and an installation not used for a professional activity. Above that, the proceeds fall under industrial and commercial profits. And the 9 kWp threshold people quote is a different one: that is the threshold for the 5.5% VAT rate on supply and installation.
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. Argile lays the panels out roof plane by roof plane and estimates output from the orientation and the shading recorded.
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
Three points of vocabulary, because they are wrong almost everywhere. The CACSI, the self-consumption agreement without injection, only covers systems that inject nothing: for self-consumption with injection up to 36 kVA, the route runs through a connection request, a connection proposal, then an access and operating contract signed with Enedis. Next, the purchase contract is not signed with Enedis, which is the grid operator, but with EDF Obligation d’achat or a local distribution utility. Finally, the service-public.gouv.fr page on selling the surplus is out of date: checked on 1 October 2025, it still describes a self-consumption premium revised each quarter, which has since been removed. Stop handing it to clients.
The client remains responsible for the grid-access contract and the choice of how to value 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.
The risk nobody writes into the contract: how solid the supplier is
A virtual battery is not an asset of the client’s, it is a claim in kind against an electricity supplier. That risk has already materialised: by an order of 13 January 2026, the French energy minister withdrew from ACTELIOS SOLUTIONS, which traded as JPME, its authorisation to buy electricity for resale to final customers, with effect from 22 January 2026. Customers were moved to backup suppliers without any interruption, but their surplus valuation arrangement disappeared.
The practical consequence fits on one line of the quote. Write that the valuation of the surplus depends on a supply contract separate from your works contract, that its continuity is not your responsibility, and that your output figures carry no promise of savings. An installer who has shown an annual gain built on an offer that has since vanished is left alone to explain it.
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.
