The tariff order of 6 October 2021, often referred to as s17, marked a significant step in the regulation of tariffs for photovoltaic installations. It introduced new rules and amended the eligibility conditions for those wishing to benefit from the purchase obligation. This article aims to dissect the changes brought about by this order, clarify the transition periods, and explain how the different tariff structures are organised according to power output and other specific criteria. We will also cover the necessary administrative procedures and the specificities related to self-consumption.

Key Points to Remember

• The s17 order, which came into force in October 2021, redefined the tariffs and eligibility conditions for solar installations.
• Tariffs are now published quarterly and depend on the installation’s power output (up to 500 kWp) and the connection request date.
• The P+Q principle aims to prevent the fragmentation of installations to benefit from better tariffs, by combining the power outputs on a single site.
• Specific conditions apply, including the installer’s qualification requirement and landscape integration requirements for larger installations.
• Self-consumption, whether individual or collective, is taken into account, with specific investment premiums for these consumption modes.

Understanding the s17 Tariff Order of October 2021

The tariff order of 6 October 2021, often referred to as

Tariff Structures and Their Evolution

The October 2021 tariff order introduced significant changes in how solar electricity is remunerated. It is important to fully understand these new structures to anticipate the potential income from your installation.

Sales Tariffs and Self-Consumption Premiums for Installations up to 100 kWp

For installations with a power output of 100 kWp or less, the order distinguishes two types of remuneration: sales tariffs for electricity injected into the grid and an investment premium to encourage self-consumption. These tariffs and premiums are digressive based on the total power output of the installation, in order to limit project fragmentation. The date of submission of the complete connection request is the determining criterion for setting the applicable tariff and premium.

Sales Tariffs for Installations from 100 to 500 kWp

Beyond 100 kWp and up to 500 kWp, the order focuses solely on sales tariffs for injected electricity. There is no longer an investment premium at this power output level. Tariffs are also digressive according to power output, but specific conditions may vary. It is essential to consult official publications for the exact amounts.

Quarterly Publication of Tariffs and Premiums

Sales tariffs and investment premiums are not fixed. They are revised quarterly. The Energy Regulatory Commission (CRE) publishes these new values each quarter, generally towards the end of the month preceding the start of the period concerned (for example, end of December for the January-February-March quarter). This publication allows for the adjustment of remuneration based on market developments and renewable energy development objectives. It is advisable to follow these publications to stay informed of current conditions, such as those announced for the third quarter of 2025 which foresee a decrease in tariffs [b2f6].

Here is an overview of the publication periods:

• End of March: Tariffs for April, May, June.
• End of June: Tariffs for July, August, September.
• End of September: Tariffs for October, November, December.
• End of December: Tariffs for January, February, March.

Remuneration is guaranteed by a 20-year purchase contract, provided that the installation is completed within 24 months following the connection request. It is possible to modify the remuneration method during the contract, under certain conditions [61c1].

Conditions for Application of the s17 Order

The tariff order of 6 October 2021, often referred to as S17 or S21 depending on the context, establishes the rules for benefiting from the purchase obligation for electricity produced by photovoltaic installations. To be eligible, several conditions must be met.

Eligibility Conditions for Photovoltaic Installations

To benefit from the provisions of this order, your installation must meet certain fundamental criteria. It is imperative that the installation is located on a building, a shed, or a canopy. This also includes agricultural greenhouses, covered playgrounds, or structures housing animals. The order applies to installations for which a complete connection request was submitted before 22 September 2025, for a maximum power output of 500 kWp. From this date, the power output limit is lowered to 100 kWp. Furthermore, the installation must either sell all the electricity produced or opt for self-consumption with surplus sales. It is important to note that installations already in service before 8 October 2021 cannot benefit from this scheme. For an overview of the small photovoltaic installations, the Energy Regulatory Commission has published an FAQ.

Requirements for the Installer

A significant point concerns the qualification of the company carrying out the installation. It is mandatory for the installer to hold a recognised professional qualification or certification. This requirement aims to guarantee the quality and safety of the installations. For installations with a power output of 100 kWp or less, a sworn statement signed by the producer and the installing company is required. For installations with a power output greater than 100 kWp, a certificate of conformity, issued by an approved inspection body, is necessary. These documents prove that the installation complies with current standards.

Specifics for Installations in Non-Interconnected Zones

Application conditions may vary for installations located in zones not interconnected to the continental metropolitan grid. This particularly concerns Corsica, the overseas departments (Guadeloupe, Guyana, Martinique, Mayotte, Réunion) as well as certain Ponant Islands inhabited year-round. These territories benefit from a specific tariff order, published on 5 January 2024. It is therefore essential to refer to the regulations specific to these zones to ascertain the precise eligibility conditions. The S21 order, in its initial version, primarily applies to mainland metropolitan France, and all eligible installations can benefit from it, subject to compliance with the criteria.

The order of 6 October 2021 details the conditions for the sale of all electricity or for self-consumption with surplus sales, as stipulated in Article R.314-7 of the Energy Code. Compliance with these conditions is paramount for the application of the current tariff order.

The Principle of Tariff Digressivity

The s17 tariff order of October 2021 introduces a mechanism for digressive purchase tariffs for photovoltaic installations. This principle aims to adjust remuneration based on the total power output of the installation, thereby encouraging smaller projects while regulating larger ones. The objective is to control the deployment of solar energy and adapt public support to market developments.

The Impact of Power Output on Purchase Tariffs

The power output of your installation is a determining factor for the purchase tariff that will be applied to you. The higher the power output, the more the purchase tariff tends to decrease. This digressive logic is implemented to reflect the economies of scale generally observed in larger installations. It is therefore important to properly assess the power output of your project from the outset to anticipate potential remuneration.

Limiting the Fragmentation of Installations

To prevent projects from being artificially divided into several smaller installations to benefit from more advantageous tariffs, the P+Q principle has been established. Power P corresponds to your project’s connection request, while power Q takes into account other installations located on the same site whose connection requests were submitted within 18 months before or after your own request. It is the sum of these two power outputs (P+Q) that is used to determine the applicable tariff bracket. This measure ensures greater equity in the application of tariffs.

Different Power Output Brackets and Their Associated Tariffs

The order defines several power output brackets, each associated with a specific purchase tariff. Here is a simplified illustration of this digressivity:

• Up to 3 kWp: These installations benefit from the highest purchase tariff.
• From 3 to 9 kWp: The purchase tariff is slightly lower than that for installations of 3 kWp and less.
• From 9 to 100 kWp: Purchase tariffs continue to decrease progressively for these brackets.
• Beyond 100 kWp: Installations in this category no longer benefit from the purchase tariffs set by the order. They are subject to tender mechanisms, which are competitive bidding procedures for the award of electricity sales contracts. These installations can also register under the EDF Tempo offer to optimise their consumption.

It is important to consult the tariff structures published by the Energy Regulatory Commission (CRE) to know the exact amounts applicable to each bracket, as these tariffs are revised quarterly. This information is available on the CRE website and is essential for evaluating the profitability of your photovoltaic project, particularly for installations up to 100 kWp which are affected by these sales tariffs and self-consumption premiums.

Integration and Power Output Criteria

To benefit from the purchase tariffs provided by the s17 order, it is essential to understand how your installation’s power output and its integration are evaluated. These two aspects are crucial for your eligibility and the level of remuneration.

The Importance of Landscape Integration

Landscape integration concerns how your photovoltaic installation fits into its environment. For certain configurations, specific rules apply. For example, roof-mounted installations, whether on a building, a shed, or a canopy, and which are parallel to the roof plane, must comply with general criteria. The same applies to systems installed on flat roofs (slope less than 10%) or those that fulfil architectural functions such as spandrels, cladding, sunshades, railings, pergolas, or curtain walls.

There was also a landscape integration premium, but this was subject to strict conditions and has no longer been available since 8 October 2023. To benefit from it, the installation had to be on the roof of a building or a shed (not a canopy), with an inclination between 10 and 75°. The modules had to ensure the roof’s watertightness, have a favourable technical opinion from the CSTB, and cover at least 80% of the roof plane surface.

Calculation of Cumulative Power Output (P+Q)

The power output of your installation is calculated in two parts: power P and power Q. Power P corresponds to the installed peak power of your photovoltaic modules. Power Q, on the other hand, represents the installed power of all other similar installations located on the same site, whether planned or already connected. Installations for total self-consumption and those that do not benefit from any other support scheme are also taken into account in this calculation of power Q. It is imperative to declare this power Q when submitting your connection request and to notify any subsequent modifications. All this information is available on the EDF OA website.

Power Output Thresholds Determining Tariffs

The different power output brackets, particularly the cumulative power output P+Q, directly influence purchase tariffs and any premiums. For installations where the P+Q power output exceeds 100 kWp, additional criteria apply, notably concerning the carbon footprint of the modules and their manufacturing process. It is important to thoroughly check these thresholds to anticipate regulatory requirements and optimise your project. The procedures for connecting your installation are detailed on the Enedis portal, which is increasingly simplifying procedures, especially for total self-consumption projects. Installations with an installed peak power output greater than 500 kWp can benefit from a remuneration top-up contract find out more about these installations.

It is crucial to clearly define the power output of your installation and to take into account the cumulative power output (P+Q) from the very beginning of your project. This will allow you to comply with the criteria of the s17 tariff order and ensure optimal remuneration for your solar electricity production.

Administrative Procedures for s17

Once your photovoltaic installation project is defined, several administrative steps are necessary to be able to benefit from the purchase tariffs provided by the s17 tariff order. These procedures aim to regulate the connection of your installation to the electricity grid and the contracting of electricity sales.

Submission of a Complete Connection Request

The first step is to submit a connection request to the relevant network operator. It is important that this request is complete to avoid any delays. It must include precise technical information about your installation, as well as supporting documents concerning planning permissions. The submission date of this request is crucial for the application of tariffs. It is often possible to submit a connection request even if planning permission has not yet been definitively obtained, with a submission receipt being sufficient initially.

Signing the Purchase Contract

After your connection request has been accepted and the necessary works completed, you will need to sign a purchase contract with the obligated buyer. This contract formalises the conditions for selling your electricity production, including the guaranteed purchase tariff over a given period. It is essential to thoroughly read and understand all clauses before signing.

Certifications Required for Compliance

Several certificates of conformity are generally required to validate your installation. These guarantee that your system complies with current technical and safety standards. For installations with a power output of 100 kWp or less, a sworn statement from the installer may suffice. Beyond this threshold, a certificate of conformity issued by an approved inspection body (such as Consuel) is often required. It is also necessary to declare the presence of any energy storage device, which may require a new specific certificate of conformity. These documents are essential for finalising the file and receiving income from electricity sales, for example via the EDF OA producer area producer area.

It is essential to keep a copy of all administrative documents and all correspondence exchanged with the various stakeholders (network operator, obligated buyer, inspection bodies) throughout the process.

Specifics of Self-Consumption with s17

The S17 tariff order, dating from May 2017, introduces specific provisions for photovoltaic installations aimed at self-consumption. It clarifies the terms for selling produced electricity, offering the producer several options for valorising their energy surplus.

Total Sale or Surplus Sale

With S17, the producer has a choice between two main methods for valorising their electricity: total sale or surplus sale. Total sale means that all electricity produced is sold to the obligated buyer. In the case of surplus sale, only the electricity not consumed by the installation is sold, with the remainder being self-consumed. This latter option allows for a reduction in electricity bills while generating additional income. It is important to note that for S11 to S17 contracts, switching from total sale to surplus sale resulted in the loss of the investment premium (Pa or Pb). The October 2021 order (S21) relaxed this rule, allowing this change without loss of premium in certain cases.

Integration into a Collective Self-Consumption Operation

The S17 order also regulates the integration of installations into collective self-consumption schemes. These operations allow several consumers and producers to share locally produced solar energy. The rules for the distribution and valorisation of energy within these collectives are defined by specific contracts, while respecting the general regulatory framework set by the tariff order. This paves the way for shared energy projects and better management of renewable electricity production and consumption.

The Self-Consumption Investment Premium

For self-consumption installations with surplus sales, S17 provides for an investment premium. This premium aims to financially support projects and encourage the development of self-consumption. Its amount depends on the installation’s power output. The eligibility conditions and calculation methods for this premium are detailed in the order. It is essential to fully understand these mechanisms to optimise the profitability of your photovoltaic project. Tariffs and premiums have since been updated, notably with the order of 6 October 2021.

It is crucial to carefully choose your electricity valorisation method (total sale or surplus sale) from the moment the purchase contract is signed, as subsequent modifications can have financial consequences, particularly on investment premiums.

Previous Tariff Orders and Their Nomenclature

Before the s17 tariff order of October 2021, several regulatory texts governed support for photovoltaic installations in France. Each of these orders introduced modifications to purchase tariffs, premiums, and eligibility conditions, reflecting the evolution of energy policies and technological costs. Understanding this chronology is essential for grasping the current framework.

Contract Nomenclature (S01, S06, S10, S11, S17)

Over time, tariff orders have been associated with nomenclature codes, allowing for the distinction between different generations of purchase contracts. These codes, such as S01, S06, S10, S11, and the most recent S17, correspond to specific application periods and distinct tariff conditions. For example, the order of 12 January 2010 (often associated with S06) marked an important step in tariff structuring.

Evolution of Tariff Orders Before 2021

The history of tariff orders is punctuated by several key texts. We can cite the order of 13 March 2002, which laid the initial foundations for support, followed by the order of 26 July 2006, then the order of 31 August 2010. Later, the order of 4 March 2011 and that of 9 May 2017 continued to adjust the scheme. Each of these texts introduced modifications to the tariff structures and application conditions, directly influencing the profitability of photovoltaic projects.

Application Conditions of Previous Orders

The orders preceding s17 had their own rules. For example, the moratorium of 9 December 2010 temporarily suspended new connection requests, before new tariffs were published. Eligibility conditions, power output thresholds considered for digressivity, and associated premiums varied significantly from one order to another. It was therefore crucial to refer to the order in force at the time of submitting the connection request to know the precise conditions. Understanding these older frameworks allows for a better grasp of the changes brought by s17, particularly concerning the calculation of cumulative power output (P+Q) [297b].

Here is an overview of notable orders before s17:

• Order of 13 March 2002: First support provisions.
• Order of 26 July 2006: Tariff adjustments.
• Order of 31 August 2010: Introduction of new tariff structures.
• Order of 4 March 2011: Modifications following market developments.
• Order of 9 May 2017: Preparation for evolution towards new regulatory frameworks.

Remuneration for Photovoltaic Installations

How your photovoltaic installation is remunerated depends on several key factors, including its power output, how you choose to sell the electricity produced, and specific installation conditions. It is important to fully understand these elements to optimise the return on investment of your project.

Different Elements of Remuneration

The overall remuneration for your installation can consist of several parts. Firstly, there is the basic tariff for the electricity you inject into the grid. These tariffs are revised quarterly by the Energy Regulatory Commission (CRE). Secondly, for small-scale installations (up to 100 kWp), an investment premium may be granted to encourage self-consumption. Another premium, linked to landscape integration, was also available under certain conditions until October 2023. It is important to know that the date of your complete connection request determines the tariffs and premiums applicable to your installation.

Prohibition of Cumulating Public Aid

An essential point to remember is that it is generally not possible to cumulate several forms of public aid for the same installation. For example, if you benefit from the electricity purchase tariff, you will not be able to claim other public support schemes that would target the same type of production or sale. It is therefore crucial to carefully choose the remuneration scheme that best suits your project from the outset. The government encourages the adoption of solar energy, for example with a reduced VAT rate of 5.5% for installations under 9 kWp [ceae].

Procedures for Changing Remuneration Mode

Once your purchase contract is signed, changing the remuneration mode is no small matter. Contractual conditions are generally strict, and modifications are limited. It is therefore advisable to carefully consider your long-term needs and objectives before committing. If you plan to modify your installation or your sales method, it is imperative to consult the terms of your contract and contact the purchasing body to ascertain the possible procedures and their conditions. Decisions made at the time of connection have a lasting impact on the profitability of your project.

Commissioning and Billing Deadlines

Once your photovoltaic installation is operational, it is essential to understand the deadlines governing its commissioning and how the billing of produced electricity will be managed. These aspects are governed by the tariff order and your purchase contract.

Duration of the Purchase Contract

The purchase contract, which binds you to the obligated buyer (such as EDF OA), has a determined duration. This duration is generally 20 years. It begins to run from the effective date of the contract, which is specified in its particular conditions. It is important to note that this period ensures stability of remuneration for your electricity production.

Contract End Conditions

At the end of the 20 years, the purchase contract terminates. At that point, you have several options. You can choose to continue selling your electricity, but the tariff conditions will then be market-based, or to no longer sell your production. It is advisable to inquire well before the end of the contract to anticipate these steps. The S21 order, for example, has seen its conditions evolve, so it is relevant to follow updates on the current tariff order.

Billing Period for s17 Contracts

The billing frequency for your production depends on the power output of your installation. For contracts falling under the S17 order, the terms are as follows:

• Installations up to 36 kWp: Billing is annual, carried out on the anniversary date of the purchase contract’s effective date.
• Installations from 36 kWp to 250 kWp: Billing becomes semi-annual.
• Installations over 250 kWp: Billing is monthly.

It is your responsibility, as the producer, to bill for your electricity. The obligated buyer provides tools to simplify this process, such as a producer area and a simplified electronic invoice. You will need to submit your production readings.

The self-consumption investment premium, if eligible, is paid according to specific terms that may vary depending on the power output and the connection request date. For installations of 100 kWp or less, it can be paid in full in the first year or spread over 5 years. Landscape integration premiums, on the other hand, are generally paid in a single instalment upon the first invoice. It is important to fully understand these mechanisms to optimise the profitability of your solar project, which can be partly financed by aid such as the Eco-PTZ.

Tariff Increase and Special Cases

Certain photovoltaic installations may benefit from an increase in their purchase tariffs or premiums. This increase aims to take into account geographical or technical specificities that could impact the profitability of a solar project. It is important to fully understand the application conditions to benefit from it.

Conditions for Tariff Increase

The tariff increase is not systematic and depends on several factors defined by the order. It may be linked to the location of the installation, particularly in areas where connection or operating costs are higher. It is essential to consult official texts to ascertain the precise criteria entitling one to this increase.

Installations Located in Corsica and the Overseas Departments and Territories

Island territories, such as Corsica and the French Overseas Departments and Territories (DOM-TOM), are often subject to specific provisions. Due to logistical constraints and higher transport costs, solar installations in these areas may benefit from increased tariffs. This aims to encourage the development of renewable energies in contexts where energy supply can be more complex. These increases are calculated to compensate for the additional costs associated with insularity and remoteness from continental grids. The objective is to make solar projects as competitive as possible in these territories, thereby promoting energy autonomy.

Non-Interconnected Ponant Islands

Similarly to the DOM-TOM, islands not interconnected to the continental electricity grid, such as certain Ponant Islands, can also benefit from advantageous tariff conditions. The absence of interconnection implies more autonomous management of electricity production, which can lead to additional costs. The tariff increases granted in these cases aim to support renewable energy projects in these isolated areas, contributing to their energy independence and reducing their reliance on imported fossil fuels. These schemes are crucial for the development of solar projects in environments where logistical and technical challenges are greater. For more details on eligibility conditions and the amounts of the increases, it is recommended to refer to the official publications relating to the s17 tariff order, which detail the specificities for each territory concerned. Understanding these mechanisms is a key step to optimising your solar project, just like choosing an RGE certified installer.

Here is an overview of the areas that may benefit from increases:

• Corsica
• Overseas Departments (Guadeloupe, Guyana, Martinique, Réunion, Mayotte)
• Overseas Collectivities (for example, Wallis and Futuna, Saint Pierre and Miquelon)
• Ponant Islands not interconnected to the metropolitan grid

In the section "Tariff increase and special cases", we address the specificities that can influence prices. It is important to fully understand these elements to make the best choices. To learn more about these topics and discover how we can help you, visit our website today!

Conclusion

The October 2021 tariff order, often referred to as S21, marked a significant step in the regulation of the photovoltaic sector. It introduced adjustments to tariff structures, power output criteria, and integration conditions, aiming to adapt the scheme to market developments and national energy objectives. Although successive modifications have refined these rules, the general spirit of the order remains: to encourage the development of solar energy while ensuring a certain stability and predictability for sector stakeholders. It is essential for professionals and individuals to stay informed of the latest updates and to fully understand the application procedures to optimise their installation projects.

Frequently Asked Questions

What is the S17 tariff order of October 2021?

The S17 order of October 2021 is like a new regulation for those who produce electricity with solar panels. It dictates how their electricity will be purchased and if they will receive additional aid. This regulation has been updated several times since its release.

What changed with this order?

The rules for setting the prices at which solar electricity is purchased have been modified. There were also special periods, called ‘transition periods’, to allow everyone to adapt smoothly to the new conditions.

How does my installation’s power output affect the sale price of my electricity?

The more powerful your installation, the lower the price at which your electricity will be purchased. It’s a bit like discounts: the more you buy in bulk, the cheaper it is per unit. The total power output of your installations on the same site counts to avoid dividing a large installation into several smaller ones to get a better price.

Who can benefit from these tariffs?

To benefit from these tariffs, your installation must comply with certain rules. For example, it must not exceed a certain power output (500 kWp, then 100 kWp after a certain date). The installer must also be qualified, and the installation must be well integrated, for example on a building.

What is collective self-consumption?

Collective self-consumption is when several people or buildings share the electricity produced by solar panels. The S17 order provides rules for this to work well and how the shared electricity is sold or used.

How are solar electricity sale prices set?

Prices are decided every three months. The date on which you officially request the connection of your installation determines the price at which your electricity will be purchased for 20 years.

Are special procedures required to sell solar electricity?

Yes, a complete connection request must be submitted. Then, you sign a purchase contract that specifies how the electricity will be sold. You must also provide documents to prove that your installation complies with all rules.

Can other aid be received in addition to these tariffs?

No, generally, you cannot cumulate these aids with other public aid for the same installation. This is to avoid receiving too much money for the same thing. There are exceptions, but the rules must be carefully checked.