Lately, there have been quite a few changes regarding how electricity grid connection costs are calculated, especially for large installations. We’re talking about the famous « refaction rate » here. If you have an installation exceeding 250 kVA, it’s important to fully understand these new rules. It can have a direct impact on your bill. We’ll try to clarify all of this together, without too much complicated jargon.
Key Points to Remember
- The refaction rate is the portion of connection costs that the grid operator covers. This reduces what you, the producer, have to pay.
- Since March 2022, the rules have changed for installations over 250 kVA. The refaction rate no longer applies in the same way, especially with the introduction of the S3REnR share.
- For installations between 250 kVA and 500 kW, the refaction rate on dedicated works is 60%. However, there is also an S3REnR share whose refaction rate decreases with power.
- ‘Grouped’ installations (same owner, connected at the same location) may be considered as exceeding 250 kVA even if each installation is smaller, which can make them liable for the S3REnR share.
- These new rules apply to connection agreements signed after 26 March 2022. For very small installations (up to 36 kVA), the Connection Proposal (PDR) is authoritative.
Understanding the refaction rate for high-power installations
The refaction rate is a financial mechanism that eases the burden on the producer when connecting their installation to the electricity grid. It represents the portion of connection costs that is covered by the grid operator, often as part of the tariffs for using public electricity grids (TURPE). For installations of significant power, particularly those exceeding 250 kVA, this rate takes on particular importance and has recently been adjusted by legislation.
Definition and role of the refaction rate
The refaction rate corresponds to the portion of connection costs not directly borne by the producer. Its main role is to reduce the producer’s initial financial contribution at the time their installation is commissioned. It applies to the works necessary to connect the installation to the grid, whether these are works specific to the installation or shared works within the framework of the Regional Schemes for Connection to Renewable Energy Grids (S3REnR).
Impact on the producer’s contribution
The application of a refaction rate reduces the amount the producer has to pay for the connection. For example, a 60% refaction rate means the producer only pays 40% of the eligible costs. This reduction can have a significant impact on the economic viability of a project, especially for large installations where connection costs can be substantial. The Climate and Resilience Law introduced modifications that directly affect this contribution.
Regulatory framework modified by the Climate and Resilience Law
The Climate and Resilience Law paved the way for a revision of connection rules, particularly for installations with power exceeding 250 kVA. A decree of 22 March 2022 concretised these changes, modifying the applicable refaction rates. These new provisions aim to better distribute the infrastructure costs necessary for the development of renewable energies, taking into account the power of the installations and their contribution to the grids. It is important to note that these new rules apply to connection agreements signed after 26 March 2022.
New provisions for installations over 250 kVA
Since the Climate and Resilience Law, significant adjustments concern the financial participation of producers for the connection of their installations. For those with power exceeding 250 kVA, new rules apply, changing how costs are distributed. It is no longer just about taking into account the works directly related to your installation, but also considering a broader contribution to the grid infrastructure.
Application of the refaction rate to dedicated works
‘Dedicated works’ refers to the elements directly necessary for your connection, such as dedicated cables or transformers. Previously, the refaction rate on these works could vary. Now, for installations with power between 250 kVA and 500 kW, a refaction rate of 60% applies to these works. This means that the producer only covers 40% of their cost as invoiced in the connection quote. This is a notable improvement compared to the old rules which could impose a heavier burden.
Consideration of the S3REnR share
Beyond dedicated works, installations with power exceeding 250 kVA are also affected by the ‘S3REnR share’. These Regional Schemes for Connection to Renewable Energy Grids aim to pool investment costs for grid development, particularly for renewable energies. The producer’s contribution to this share is calculated based on the power of their installation. It is important to note that even for low-voltage installations, if the sum of the powers of several installations belonging to the same producer exceeds 250 kVA, they collectively become liable for this share. The Climate and Resilience Law introduced this measure to better distribute the costs associated with grid extension and reinforcement.
Determination of the refaction rate according to power
The power of your installation is the key factor determining the applicable refaction rate, particularly concerning the S3REnR share. For installations between 250 kVA and 500 kW, the refaction rate on this share starts at 60% and gradually decreases as the power increases. For example, a 300 kVA installation will benefit from a higher refaction rate on the S3REnR share than a 490 kVA installation. This decreasing scale aims to adjust financial participation according to the size and potential impact of the installation on the grid. It is therefore essential to know the exact power of your project to anticipate connection costs. The NF EN 50549 standard, which will be mandatory from 1 January 2025, also frames the technical aspects of connection, ensuring compliance with European and French requirements for grid stability. For more details on compliance obligations, consulting Enedis’ technical documents is a recommended step.
Calculation of the refaction rate for installations between 250 kVA and 500 kW
For installations with power between 250 kVA and 500 kW, the calculation of the refaction rate follows specific rules, introduced notably by the decree of 22 March 2022. These new provisions aim to adjust the producer’s participation in connection costs based on the size of their installation and their contribution to the Regional Schemes for Connection to Renewable Energy Grids (S3REnR).
Refaction rate on dedicated works
Installations in this power range benefit from a 60% refaction rate applied to dedicated works. These works correspond to the elements directly necessary for connecting your installation to the public distribution network. Concretely, this means that the producer will only cover 40% of the cost invoiced for these works in the connection quote. This is a significant portion of the initial cost coverage.
Evolution of the refaction rate on the S3REnR share
Beyond dedicated works, installations between 250 kVA and 500 kW are also affected by the S3REnR share. Unlike smaller installations, the refaction rate on this share is not fixed. It gradually decreases as the power of the installation increases. The refaction rate is calculated according to the formula: 60% – (P – 0.25) x 80%, where P is the installation’s power expressed in MW. This formula shows that the higher the power in this range, the greater the producer’s share of the S3REnR share, thus reducing the refaction rate.
Influence of power on the refaction rate
The interaction between the refaction rate on dedicated works and that on the S3REnR share creates a dynamic where the installation’s power plays a decisive role. While the rate on dedicated works remains stable at 60% for this category, it is the evolution of the rate on the S3REnR share that modulates the overall refaction rate. For example, a 250 kVA installation (i.e., 0.25 MW) will benefit from the highest refaction rate on the S3REnR share, while a 500 kW installation (i.e., 0.5 MW) will see this rate decrease. It is therefore important to accurately anticipate the exact power of your project to precisely estimate your contribution to connection costs, by consulting the connection terms.
Here is a summary table to illustrate this influence:
| Power (P in MW) | Refaction rate on dedicated works | Refaction rate on S3REnR share | Overall refaction rate (approximate) |
|---|---|---|---|
| 0.25 (250 kVA) | 60 % | 60 % | 60 % |
| 0.30 (300 kVA) | 60 % | 56 % | 58 % |
| 0.40 (400 kVA) | 60 % | 48 % | 54 % |
| 0.50 (500 kW) | 60 % | 40 % | 50 % |
It should be noted that these calculations are based on regulatory provisions and may be subject to adjustments according to regional specificities or future legislative developments on solar panel connection.
Specific cases of grouped installations
When several renewable energy production installations are considered to form a group, the rules for calculating the refaction rate may be modified. It is therefore essential to correctly identify these situations to apply the regulations properly.
Criteria for subjection to the S3REnR share
An installation is considered part of a group if other installations using the same type of energy, belonging to the same company or related companies, are already connected or awaiting connection to a substation whose voltage level is immediately higher than their own connection voltage. Two companies are considered related if one holds the majority of the other’s capital, or if both are under the control of the same third company. This concept of grouping is crucial because it can lead to subjection to the S3REnR share even for individual installations whose power is less than 250 kVA.
Calculation of cumulative power for grouped installations
In the case of grouped installations, the total power taken into account for calculating the S3REnR share is the sum of the connection powers of all concerned installations. For example, if a producer has a first installation of 100 kVA and creates a second of 200 kVA connected to the same HTA-BT substation, the two installations are then considered grouped. The S3REnR share will be calculated on a cumulative power of 300 kVA (100 kVA + 200 kVA).
Consequences for the refaction rate
Subjection to the S3REnR share for grouped installations has direct repercussions on the calculation of the refaction rate. The total cumulative power determines the producer’s level of participation in the investment costs of the grids. It is important to note that installations whose cumulative power is less than 250 kVA are exempt from paying this share, in accordance with Article D442-22-1 of the Energy Code. The precise determination of the total power is therefore a key step in evaluating the applicable refaction rate and the producer’s financial contribution. Dedicated works, intended for the connection of the installation to the grid, are also affected by this refaction rate, the calculation of which can be influenced by the overall power of the group of installations.
It should be noted that installations for total self-consumption, without injection into the grid, are not subject to the S3REnR share, as their connection power is considered to be zero.
Application of the new refaction rates
The entry into force of these new tariff provisions marks an important step for renewable energy producers. It is therefore essential to fully understand when these new rules actually apply. The modifications introduced by the decree of 22 March 2022 primarily concern installations with power exceeding 250 kVA, but also those up to 500 kW. These changes directly impact how connection costs are distributed.
Effective date of the new rules
The new rules relating to refaction rates came into effect for connection agreements signed from 26 March 2022. This means that if your connection proposal was accepted and the agreement was signed after this date, you are affected by these new provisions. It is important to note that for installations with power equal to or less than 36 kVA, the connection proposal (PDR) serves as the agreement.
Connection agreement as reference
The connection agreement is the key document that determines the application of refaction rates. The date of signature of this agreement is authoritative for knowing whether the old or new rates apply to your project. Grid operators, such as Enedis, rely on this date to establish the connection quote and calculate the producer’s contribution. A connection request can be submitted before a deadline, but it is the signing of the agreement that triggers the tariff application according to the rules in force.
Cases of installations with power equal to or less than 36 kVA
For smaller installations, up to 36 kVA, the process is slightly simplified. The connection proposal (PDR) issued by the grid operator acts as the agreement. Therefore, it is the issue date of this PDR that determines the application of refaction rates. Although these installations are generally not affected by the S3REnR share, it is always good to check the specifics of your case.
It is crucial to carefully consult your connection proposal and the associated agreement to precisely identify the tariff conditions applicable to you.
Works covered by the refaction rate
To properly understand how the refaction rate applies, you must first know which types of works are taken into account. Broadly speaking, we distinguish between two main categories: ‘dedicated works’ and those falling within the framework of the Regional Schemes for Connection to Renewable Energy Grids (S3REnR). The distinction is important because it directly influences the calculation and amount of your connection contribution.
Identification of dedicated works
Dedicated works are essentially the elements that directly connect your installation to the public grid. Think of everything created specifically for you, from the connection point to the interface with wider networks. This includes, for example, HTA outgoing cells with their protections, HTA/HTA transformers, HTA and BT cables (underground or overhead), HTA/BT substations (with their busbars, transformers, switchboards), and of course, metering installations. These elements are the first line of defence for your connection. They are described quite precisely in the connection conditions provided by Enedis.
Definition of S3REnR works
S3REnR works are a little different. These are more substantial works, often larger grid infrastructures (such as HTB/HTA transformers, HTA busbars in source substations) that are created or reinforced to accommodate new renewable energy production, including yours. The idea behind S3REnR is to pool investment costs for the grid. Your participation in these costs is via an ‘S3REnR share’. The works created within this framework are therefore partly financed by producers, while those that are simply reinforced are generally at the expense of grid operators. This is a way of distributing the financial effort to adapt the grid to the growing needs of renewable energies.
Distinction between dedicated works and S3REnR works
The key difference is that dedicated works are truly specific to your installation, while S3REnR works are broader infrastructures that benefit several producers or the entire grid. For example, if you install a small solar power plant, the cables running from your inverter to the grid connection point will be considered dedicated works. If, to connect this plant, an existing transformer in an electrical substation needs to be reinforced or a new one created, then this transformer and associated equipment will fall under S3REnR. It is important to note that works carried out on your private property, even if necessary for connection, generally do not benefit from this refaction rate. The UTE C 15-712-1 guide provides details on the technical aspects of photovoltaic installations, which can indirectly influence how these works are designed and therefore their cost.
The role of Regional Schemes for Connection to Renewable Energy Grids (S3REnR)
The Regional Schemes for Connection to Renewable Energy Grids, better known by the acronym S3REnR, play an important role in the development of green energies. They aim to organise and plan the investments necessary to connect new renewable energy production installations to the electricity grid. Essentially, they allow for the pooling of connection costs among different producers. This approach helps make the deployment of renewable energies more affordable for everyone.
Pooling of investment costs
The principle behind S3REnR is to distribute the costs associated with creating or reinforcing grid infrastructure. Instead of each producer bearing the total cost of their connection alone, S3REnR allows these expenses to be shared. This is done notably via an ‘S3REnR share’, a contribution calculated based on the installation’s power. This pooling is particularly relevant for installations whose power exceeds a certain threshold, such as those over 250 kVA, which are subject to this contribution. The objective is not to hinder project development with prohibitive connection costs. For more information on the technical aspects of connection, you can consult the connection conditions.
Producers’ participation in cost burden
Although S3REnR aims for pooling, producers are not entirely exempt from participation. Installations with power exceeding 250 kVA contribute financially to these investments via the S3REnR share. The amount of this share is calculated based on the installation’s connection power and the overall cost of the works planned in the regional scheme. It is important to note that these amounts are updated annually and may vary by region. This participation is a counterpart to the possibility of connecting to the grid under optimised conditions.
Impact of S3REnR on the refaction rate
S3REnR has a direct influence on the calculation of the refaction rate applied to connection costs. For the installations concerned, the refaction rate on the S3REnR share is progressively reduced based on power. For example, for an installation between 250 kVA and 500 kW, the refaction rate on this share decreases as the power increases. This means that the portion of the cost borne by the producer for this specific component of the connection can vary. It is therefore essential to fully understand how these different elements articulate to estimate the final cost of your connection. The chosen connection power has a direct impact on these calculations, and it is sometimes possible to adjust it to optimise costs, as explained in power management.
S3REnR are strategic tools that allow electricity grids to be adapted to the growing needs of renewable energies, by ensuring a more equitable distribution of infrastructure costs among sector players. They are part of a broader regional energy planning approach, similar to the Energy Development Schemes (SDE) that define objectives at a territorial level, as shown by regional plans.
Here is a summary table of the application of the S3REnR share:
| Installation Power | Subjection to S3REnR share |
|---|---|
| Less than 250 kVA | No |
| Greater than 250 kVA | Yes |
| Grouped installations (sum of powers) < 250 kVA | No |
| Grouped installations (sum of powers) ≥ 250 kVA | Yes |
Understanding the S3REnR share
The S3REnR share represents the financial contribution of renewable energy producers to the investment costs of electricity grids, as defined by the Regional Schemes for Connection to Renewable Energy Grids (S3REnR). This mechanism aims to pool the expenses necessary for reinforcing and extending grids to accommodate new production installations.
Calculation of the unit share
The calculation of the unit share is based on the total cost of the works planned in the S3REnR, divided by the scheme’s overall reception capacity. In other words, the amount of investments needed for the works to be created is taken and related to the total capacity that the grid can absorb. This calculation allows for the determination of a tariff per kilowatt (kW) installed. The values of these shares can vary from one region to another and are subject to change.
Annual update of the share
It is important to note that the S3REnR share is updated annually. This update generally applies to connection offers issued after 31 January of each year. However, significant modifications to the S3REnR, such as a revision or adaptation, may lead to the application of a new share from the date of the connection request, in accordance with the provisions of the Energy Code. It is therefore advisable to consult the most recent information available on the Caparéseau website.
Conditions for applying new share values
The application of new share values depends on several factors. For individual or grouped installations whose connection power exceeds 250 kVA, the share is calculated by multiplying the installation’s power by the unit share. Installations whose cumulative power is less than 250 kVA are generally exempt. Attention must be paid to specific cases, particularly for grouped low-voltage installations which may be subject even if their individual power is below this threshold. Connection projects, whether subject to the Declaration, Registration, or Authorisation regime, must take these provisions into account according to their power.
Concrete examples of refaction rate calculation
To fully grasp the new rules, there’s nothing like looking at a few practical examples. This allows us to concretely visualise how the refaction rate applies and what impact it has on the final connection cost. The calculations may seem complex at first, but by breaking them down, it becomes easier to understand. It must be said that taking into account dedicated works and the S3REnR share adds layers of calculation.
Simulation for a 300 kVA installation
Let’s take the case of a renewable energy production installation with a power of 300 kVA. According to the Climate and Resilience Law, this installation is subject to the application of the refaction rate on dedicated works and on the S3REnR share. The refaction rate on dedicated works is set at 60%. For the S3REnR share, the rate decreases with power. For 300 kVA (i.e., 0.3 MW), the calculation is as follows: 60% – (0.3 – 0.25) x 80% = 60% – 0.05 x 80% = 60% – 4% = 56%. Thus, the producer benefits from a 60% refaction on dedicated works and 56% on the S3REnR share. This significantly reduces their contribution to the total connection cost.
Analysis of a grouped installation exceeding 250 kVA
Imagine several production installations belonging to the same producer, connected to the same distribution substation. If the sum of their powers exceeds 250 kVA, they are considered a grouped installation and are therefore liable for the S3REnR share. For example, two installations of 150 kVA each total 300 kVA. They will be subject to the same calculation rules as the previous example. The cumulative power is the determining criterion for subjection to the S3REnR share, even if each individual installation is less than 250 kVA. It is therefore important to carefully check the total power of installations belonging to the same producer.
Impact of power variations on the refaction rate
The refaction rate is not fixed and varies according to the installation’s power, particularly for the S3REnR share. Here is a table illustrating this variation for installations between 250 kVA and 1 MW:
| Installation Power (P) | Refaction on dedicated works | Refaction on S3REnR share |
|---|---|---|
| 250 kVA ≤ P ≤ 500 kW | 60 % | 60 % – (P – 0.25) x 80 % |
| 500 kW < P < 1 MW | 40 % | 40 % – (P – 0.5) x 40 % |
As can be seen, the higher the power in these ranges, the lower the refaction rate on the S3REnR share. For example, a 500 kW installation benefits from a 60% refaction on dedicated works and 20% (60% – (0.5-0.25)*80%) on the S3REnR share. A 750 kW (0.75 MW) installation will have 40% refaction on dedicated works and 30% (40% – (0.75-0.5)*40%) on the S3REnR share. These examples show the importance of accurately knowing the exact power of your project to anticipate connection costs. The connection quote provided by Enedis is the reference document for these calculations, and it is advisable to fully understand it before committing. Connection costs can vary, and a good estimate is necessary for your project budget.
It is essential to note that connection agreements signed after 26 March 2022 are subject to these new provisions. For installations with power equal to or less than 36 kVA, the connection proposal (PDR) serves as the agreement.
Understanding these mechanisms is crucial for renewable energy producers. The refaction rate is a key element that directly influences a project’s profitability. It is therefore recommended to seek professional advice to ensure that all regulatory and financial aspects are correctly taken into account. The role of the refaction rate is to find a financial balance while facilitating the deployment of renewable energies.
Exclusions and special cases of the refaction rate
Installations for total self-consumption without injection
For installations that consume all the energy they produce, without injecting any back into the grid, the question of the refaction rate does not arise in the same way. Indeed, these installations are considered to have zero connection power. Consequently, they are not subject to the S3REnR share. If, hypothetically, they were, this share would in any case be zero, making the calculation of the refaction rate inapplicable in this specific context.
Works carried out on private property
It is important to distinguish between works that constitute the connection to the public grid and those located on your private property. When works are carried out entirely on private property, at the user’s request and subject to compatibility with technical rules, the part of the works carried out on your land does not benefit from any refaction. The cost of these works therefore remains entirely at your expense. This typically concerns the installation of a delivery point on your plot, if technically feasible and desired.
Installations with power exceeding 5 MW
The refaction rate mechanism, as modified by the Climate and Resilience Law and the decree of 22 March 2022, specifically applies to installations with power below 5 MW. Beyond this threshold, installations no longer benefit from any partial coverage of connection costs. This means that for projects of 5 MW and above, the producer bears the entirety of the costs related to connection, without application of refaction on dedicated works or on the S3REnR share. The calculation of grid connection costs therefore becomes a major financial issue for these large installations.
It is essential to correctly identify the power of your installation and to check if it falls within the power ranges eligible for the refaction rate. The thresholds are clearly defined, and non-compliance with these criteria leads to a different application of the rules for cost coverage.
Certain situations do not follow the usual rules for calculating energy savings. These are called exclusions and special cases. For example, if you have very specific needs or if your installation is a little different, this can change how the refaction rate is calculated. To find out if your case is special and how it might affect you, please visit our website. We have clear information to help you understand.
In summary and for further reading
These new rules concerning refaction rates for installations over 250 kVA mark an evolution in the coverage of connection costs. It is important for producers to fully understand these changes, particularly the distinction between dedicated works and the S3REnR share, as well as how the power of their installation influences these rates. Staying informed of developments and, if necessary, consulting reference documents or a professional will help navigate these new provisions optimally and anticipate the costs associated with connecting your installations.
Frequently Asked Questions
What is the refaction rate and what is its purpose?
The refaction rate is a bit like financial aid for connecting your installation to the electricity grid. It reduces the portion of connection fees you have to pay. Basically, the grid operator covers part of the costs, which means you pay less upfront.
Who is affected by these new refaction rules?
These new rules mainly concern installations that produce electricity and whose power exceeds 250 kilovolt-amperes (kVA). Previously, it was mainly for smaller installations, but the law has changed things for larger ones.
How is the refaction rate calculated for installations between 250 kVA and 500 kW?
For these installations, the calculation becomes a little more complex. There’s one part for ‘dedicated works’ (those directly serving your installation) and another part for ‘S3REnR works’ (which serve to pool costs for everyone). The refaction rate decreases as your installation’s power increases, especially for the S3REnR part.
What is the ‘S3REnR share’ and why is it important?
The ‘S3REnR share’ is the amount you pay to contribute to the construction or improvement of the electricity grids needed to accommodate renewable energies. It’s a way of sharing the costs among all those who benefit from these improvements, especially if your installation is medium to large (over 250 kVA).
What is a ‘grouped installation’ and how does it affect the refaction rate?
A grouped installation is when several installations belonging to the same owner are connected at the same location. If the total power of all these installations exceeds 250 kVA, they are all considered a single large installation and must pay the S3REnR share, which can modify the applied refaction rate.
When did these new refaction rate rules come into effect?
These new rules apply to connection contracts that were signed after 26 March 2022. If you signed your contract before this date, the old rules apply.
What types of works are covered by the refaction rate?
There are two main categories: ‘dedicated works’, which are directly linked to your installation, and ‘S3REnR works’, which are larger infrastructures for the grid. The refaction rate can be different for these two types of works, especially for installations with power exceeding 250 kVA.
Are all renewable energy production installations affected?
No, not all. Very small installations (up to 36 kVA) have slightly different rules, and those designed for total self-consumption without feeding electricity back into the grid are generally not affected by the S3REnR share. Installations over 5 megawatts (MW) are also excluded from these new refaction rules.
