Photovoltaic connection refused or limited: who pays for network reinforcement?

The short answer

A refusal or limitation of connection does not necessarily mean that your roof is unusable. It may mean that the requested power cannot be accommodated at the planned point without modification, that a study is incomplete or that the project must be connected to another point. The first instinct is to ask for a written technical decision, not to choose equipment based on a telephone sentence.

The question “who pays for the reinforcement?” » does not have a single answer. It is necessary to distinguish between the line which connects your installation to the network, the equipment specific to the connection, a general reinforcement of the network which benefits several users and the internal costs of your building. The rules and prices may depend on the power, the voltage level, the connection point and the qualification of the work.

ElCom describes the network reinforcements necessary for the resumption of electricity produced by renewable installations. The official page notably recalls the criteria of necessity and economicity, as well as compensation mechanisms by Swissgrid for certain reinforcements. It also indicates reference amounts for general low-voltage reinforcements and for certain connection lines of more than 50 kW. These indications do not replace a local calculation and do not allow one to conclude that a quote is fair without seeing the diagram.

For a buyer, the right method is to separate in the offer: study and connection request, work in the switchboard, private line, DSO work, general reinforcement, meter, control and possible single contribution. Each line must have a manager and a base.

Why a connection may be limited

The distribution network was built to transport electricity to buildings. High solar production reverses the flow at certain times and can increase voltage on a street. A transformer may reach its thermal limit, a line may have an insufficient section or a substation may already accommodate several projects. The DSO must analyze the situation at the connection point, not just the power of your modules.

The peak power of the panels is not always the injected power. The inverter, self-consumption, battery and export setpoint modify the flow. A 100 kWp installation with power limitation may have a different impact from a smaller installation which exports all its peak. The file must therefore specify the DC power, the AC power and the maximum exported power requested.

The timing of the request also matters. A network that accepts a project today can request a new study after the arrival of another producer or a major consumer. This does not mean that the DSO can change any condition without explanation; this means that the connection is a technical situation which must be documented on the date of the study.

A refusal may be temporary. A diagram, setting information or confirmation of a limitation may be missing. It can also be definitive for the requested point but possible at another voltage level or at another distance. Always ask if the answer is “impossible”, “impossible at this power”, “impossible at this point” or “possible after work”.

The four works to be separated in the estimate

Connection specific to the building

The general panel, protections, cables between inverter and connection point, cable trays and any roofing work may be part of your project. They must be included in the offer from the installer or electrician. If the building requires adaptation to comply with safety rules, this cost must not be presented as a reinforcement of the public network.

The connection line

The line that connects your installation to the network may have a different logic from general reinforcement. For a large installation, it can be long, buried, sized for the power requested or linked to a new station. The contract and the DNO regulations determine the producer's contribution. Ask for a plan, length, section, starting point and ending point.

General strengthening

General reinforcement can improve network capacity beyond just your connection. It can benefit other producers, heat pumps or charging stations. ElCom indicates that certain reinforcements necessary for the connection of renewable producers are subject to compensation via Swissgrid, according to the applicable conditions. It is therefore necessary to ask how the GRD classifies the work and what part is treated in this mechanism.

The counter and measurement

The bidirectional meter, metering system, communications and commissioning have their own costs. A smart meter may be required or simply expected. ElCom points out that measurement systems and their costs are linked to network rules and the installed equipment. Do not automatically place the meter in the “reinforcement” section: ask for its nature and billing duration.

What the compensation framework says, with caution

The ElCom page on grid reinforcements explains that costs can be offset by Swissgrid when reinforcement is necessary and economically justified to connect a renewable installation. It mentions compensation of 59 CHF per kW for general low voltage reinforcements within the framework described. For installations exceeding 50 kW, it also mentions a limit of CHF 50 per kW for certain reinforcements of the connection line and a reimbursement to the producer by the DNO via Swissgrid.

These amounts are not a universal bill or an automatic right to receive an amount. They are linked to categories and conditions. The threshold, date of the study, voltage level, recognized power, necessity and procedure of the DSO must be verified. An offer that says “Swissgrid pays everything” is as unreliable as one that says “the owner always pays everything”.

Ask for the DSO's classification decision: internal structure, connection line, general reinforcement or combination. Also ask who advances the cost, who orders the work, when any compensation is received and what happens if the final power changes. The payment flow may be different from the final economic manager.

What to do with denied power

Start by asking for a costed alternative. Lower injection power, a different orientation, a smaller inverter or an export setpoint can reduce the impact on the network. The installer must show the annual energy lost in this solution, not just say it is “acceptable”.

Storage can reduce the peak, but the DSO may require specific control and guaranteed behavior. A battery installed just to obtain permission is not automatically profitable. Compare the cost of the battery with that of the reinforcement, the duration of the restriction, the value of the energy not injected and the future needs of the building.

Another connection point may be possible, but a longer distance creates new costs. Ask for the plan and available power. For a PPE or an agricultural building, a common connection may require a study of property, easements and internal distribution. The technical choice must remain compatible with user contracts and meters.

Finally, a temporary limitation may be acceptable if accompanied by a timetable. Ask for the steps, those responsible, authorizations and the date of re-evaluation. Without a date or document, “the network will soon be strengthened” is not a banking hypothesis.

How to dispute or request clarification

Write to the DSO with the reference of the installation and request the response in the form of a note or letter. Stay precise: DC power, AC power, requested injection power, connection point, date, planned storage and possible limitation. Ask if the refusal is based on thermal overload, voltage, protection, lack of capacity or an incomplete record.

If the document seems contradictory, request a technical meeting with the DSO and the installer. Both sides should look at the same pattern. Keep the versions of the plans, as a change to the inverter can change the demand. Do not ask the installer to declare an artificially low power if the equipment can inject more without a verifiable limiting device.

If there is ongoing disagreement over a tariff or qualification, independent electricity or energy law advice can help. ElCom has information skills and procedures, but each dispute must be presented with documents. Emotional exchanges or forum opinions do not replace the technical file.

The content of a good connection offer

The offer should show a single-line diagram, the measuring point, the power of each equipment, the export instruction, the protection, the trench or cable work and the coordination schedule. It should indicate what depends on acceptance of the DSO and what remains due if the request is refused.

Ask for an “accepted project” version and a “limited power” version. The comparison must display initial cost, production, self-consumption, injection, curtailed energy, maintenance and tariff assumptions. For a large project, add the cost of financing during the wait, crane rental, site permits and coordination with a possible new building.

Connection charges must be linked to an identifiable invoice or payment. If the installer adds a “network reserve” line without amount, responsibility or condition, ask for justification. A reserve may be reasonable at the preliminary stage, but it must be transformed into a documented price or range before ordering.

Example of reading a refusal

Let's assume that the DSO accepts 30 kW of injection at the current point but requests reinforcement for 80 kW. This is not a rejection of the entire installation. It is necessary to compare an installation limited to 30 kW, an 80 kW installation with storage or limitation, and an alternative connection. In each case, estimate the kWh produced, consumed, exported and not recovered.

If the reinforcement improves the neighborhood network, ask which part is general reinforcement. If a private line is extended only for your building, ask about the liability and cost of that line. If the study recommends a transformer, ask if its power is linked only to your project or to several connections.

The cheapest option to build is not always the best over twenty years. A strong limitation can reduce income but avoid heavy construction. Conversely, reinforcement can make a common battery, terminals and heat pumps possible. The right choice depends on the length of ownership and future uses, not just the initial bill.

Questions to ask the DSO and the installer

The answers must correspond to the same plan. A phrase from the GRD on a line cannot justify an amount from another category in the quote.

Checklist before paying for reinforcement

First obtain the written decision from the DSO and the plan of the connection point. Check that the power requested in the decision corresponds to that of the offer. Ask for the basis for calculating any contribution and the reference to the connection regulations.

Then compare the scenarios. The base case should show the limited solution; the complete scenario must show reinforcement; a third scenario can integrate storage, control or other connection point. Vary the injection rate and the commissioning time. The money tied up during the work also has value.

Finally, enter the conditions in the contract: accepted connection, responsibility for the work, possible compensation, maximum cost, deadline, treatment of reduced power and right of termination if an essential condition changes. Do not pay a non-recoverable advance for a work which has not yet been validated by the GRD.

Follow-up after the connection agreement

Acceptance of the DSO is not the end of coordination. A change in power, a change of inverter or a battery added after the study can render the initial plan obsolete. Before ordering another model, have it confirmed that the new data sheet remains in the accepted request. The same principle applies to the extension of an existing installation: a few additional modules can modify the DC power, the protection and the injection tip.

Request a schedule that separates agreement, hardware ordering, network work, indoor installation, testing and meter replacement. A roof may be ready but the connection is not. In this case, the energy produced must not be put into service without the planned procedure. The contract must specify who bears the risk of delay and how deposits are protected.

Upon receipt, ask for the test reports and proof of the limitation or permitted power. The inverter settings, the single-line diagram and the DSO coordinates must remain accessible to the owner. If a problem appears after the first sunny days, note the date, measured values ​​and weather conditions. A simple trace helps distinguish between a network limit, a measurement failure and a production fault.

Finally, check the final invoice against the quote and the decision of the DNO. Expected compensation from Swissgrid or an amount advanced by the installer may follow a different schedule. The file must show the gross amount, any compensation, taxes and balance. This transparency is particularly important when several buildings or owners share the same network extension.

Do not delete old plans when the project is modified. Keep the rejected version, the limited version and the final version with their dates. This makes it possible to understand why the power has changed and to prevent a future participant from reintroducing a configuration that the network had not accepted. A good archive protects both the owner, the manager and the installer.

This archive can also be used during a sale of the building. The buyer will know what power is authorized, what meters are installed and if an extension has been studied. It avoids repeating a costly request or promising future power that has never been validated.

Traceability is therefore a part of the connection, not a secondary administrative formality.

The file after commissioning

Acceptance of the DSO must be followed by submission of documents: final plan, settings, tests, meter, invoices and possible compensation. If another inverter, battery or modules are added, confirm that the initial study remains valid. A new configuration should not be put into service on an old assumption.

Keep the rejected version, the limited version, and the final version. During a sale or extension, this timeline shows what power and connection point were actually accepted. It protects the owner and avoids repeating an unnecessary study.

Prepare the follow-up after the response from the DSO

A connection agreement should not be treated as a simple green light. It is valid for a power, a diagram, a point and a date. If the inverter, battery, exported power or number of modules changes, have the new configuration checked before ordering. An extension does not automatically benefit from the old decision.

Ask for a schedule that separates study, agreement, DSO work, interior installation, meter, testing and commissioning. The roof may be ready when the network is not. The contract must indicate who is responsible for a delay, how deposits are protected and what happens if final power is reduced.

Think about future charges, but don't charge them without a scenario. A heat pump, terminals or a neighboring building can justify additional capacity if the date and the benefit are real. A larger line built during a construction site may be rational; a vague reservation is not. Compare immediately needed capacity to documented expansion.

Upon receipt, obtain final diagram, measured power, report, inverter settings, meter and DSO coordinates. Check the invoice against the decision and the quote. Possible compensation may follow a different schedule; it should be presented as a hypothesis until the category and procedure are confirmed.

Compare limitation, reinforcement and storage

A refusal of power can produce three valid offers: reduce exports, strengthen the network or store part of the surplus. Compare them on the same surface and the same curve. The limited variant must show clipping; the network variant must show time, cost and category of work; the battery variant must show kWh charged, returned, losses and replacement.

Include future charges only when documented. A heat pump, a terminal or a building extension can modify the value of a reinforcement. A scenario without a date or without an identified user remains an option, not an acquired benefit. Show the capital tied up during the study and the construction site.

After the work, check the power on the meter and archive the parameters. If a new service provider must intervene, he must distinguish between private line, general reinforcement, meter and interior installation. This separation protects the owner when a bill or compensation is discussed.

Conclusion

A refused or limited photovoltaic connection is a matter to be clarified, not a battle of slogans. The question of payment depends on the type of work and network conditions. ElCom provides a useful framework for understanding necessity, economics and compensation, but only the DSO file allows you to know the solution for your address.

Request a clear separation between building, line, general reinforcement and measurement. Compare a limitation with a reinforcement and possible storage on the same production curve. You will then be able to decide with real visibility on the cost, the deadline and the kWh which remain recoverable.