The indexation of photovoltaic feed-in tariffs is based on a precise mechanism, often summed up by the term « coef k ». This coefficient adjusts the price at which solar electricity is purchased each year to take account of changes in production costs and economic context. Many producers wonder how this coef k is determined, exactly what its purpose is, and what consequences it may have for the profitability of their project. This article explains simply how this indexation system works, the indices it is made up of, and what it actually changes for photovoltaic installations.
Key points to remember
- The coef k is used to adapt the purchase price of solar electricity every year in line with economic changes.
- This coefficient is based on several official indices, such as labour costs, the price of aluminium or the long-term interest rate.
- The indexation formula depends on the power of the installation and the commissioning date.
- For installations under 9 kWc, indexation has not applied since 2025.
- Complying with indexation procedures via coef k guarantees a stable tariff over 20 years, though some adjustments are possible under legislation.
Understanding the role of coef k in the indexation of photovoltaic feed-in tariffs
Definition of coef k and its importance
The k coefficient, often called coef k, is the indexation factor that adjusts the purchase tariff for electricity generated from photovoltaics according to economic trends. Without this coefficient, the tariff would remain fixed despite changes in production costs and market conditions. It relies on indices published regularly by bodies such as INSEE. This makes it possible to track real-world factors, such as changes in the price of materials or wage costs. The coef k thus prevents a gap developing between the regulated tariff and economic reality as experienced by solar producers, which is vital for investment stability.
By adjusting the purchase price to the economic climate, coef k enables economic changes to be accommodated without disadvantaging producers or buyers over the life of the contract.
Objectives of tariff indexation
The indexation of tariffs aims to achieve several clear goals:
- Maintaining the appeal of the solar sector, even when production costs change.
- Reducing financial risk for project sponsors over the long term (often 20 years).
- Ensuring appropriate remuneration for each installation, whether small or large.
- Adjusting the purchase price to changing costs, as seen in the quarterly update of the purchase price influenced by coef k (example of indexed contribution).
When investing in a solar installation, it becomes easier to anticipate income, as the price adjusts transparently.
Impact on PV project profitability
The coef k has a direct impact on the profitability of solar projects. If the constituent indices increase, the tariff rises, offsetting higher costs (materials, salaries, interest rates). Conversely, falling indices reduce the tariff in line with falling charges or technical progress. Some concrete effects:
- Stability of the internal rate of return (IRR), thanks to the annual tariff adjustment.
- Ability to maintain margins when investment costs rise quickly.
- Greater project resilience to economic volatility, reassuring lenders and making it easier to access credit (role of kWc and optimisation).
| Economic parameter | Without indexation | With coef k |
|---|---|---|
| Rising material costs | Profitability decreases | Tariff adjusted, profitability maintained |
| Falling interest rates | No effect | Tariff readjusted down |
Every photovoltaic project owner therefore needs to pay attention to how the coef k evolves, as it largely determines investment performance over time.
The basic principles of feed-in tariff indexation for photovoltaics
In photovoltaics, it’s common to confuse indexation with degression, whereas they are two opposite mechanisms forming the feed-in tariff formula. Indexation aims to adjust the tariff in line with economic cost changes (wages, raw materials, financing), while degression seeks to lower it gradually in line with the structural fall in equipment costs.
- Indexation is based on economic indices, generally published by INSEE, to offset inflation or increasing production-related charges.
- Degression applies a periodic reduction according to the volume of new installations or public policy objectives: the more projects are submitted, the sharper the decrease.
- These two mechanisms operate on different timescales: degression is often quarterly, while indexation is annual (over the life of the contract – 20 years in most cases).
In practice, the feed-in tariff you obtain therefore takes into account both the regular fall in PV costs and a correction to prevent inflation eroding your investment’s profitability.
Current regulatory framework
The PV feed-in tariff indexation system is based on a set of tariff decrees regularly updated by the French authorities. At present, the regulatory framework provides for:
- A legal guarantee of the feed-in tariff for all producers with a contract with EDF OA or another obligated purchaser.
- Possible changes every new quarter for tariffs applied to new applications; once your tariff is secured, it evolves solely by annual indexation until the end of the contract.
- A system of coefficients (such as BN and K) that put indexation into effect according to indices (wages, production, interest rates, etc.): their calculation and application methods are specified in the contract terms, as outlined on the page on the recalculation of the indexed feed-in tariff.
Synthetic table of key regulatory developments:
| Year | Decree/Event | Impact on indexation |
|---|---|---|
| 2021 | Application window >500 kWc opened | New formula, 7 indices taken into account |
| 2022 | 28 July decree | Upward revision of tariffs and indices |
| 2025 | Mandatory security deposit >100 kWc | Financial security, adjustment of terms |
Eligibility criteria for indexation
Not all photovoltaic projects benefit from exactly the same method of indexation. The criteria are precise:
- Installed capacity: Indexation procedures vary depending on whether your installation is below 9 kWc, between 9 and 100 kWc, or above 100 kWc. For example, large power stations have their own index references.
- Type of contract: Only contracts falling under the feed-in obligation or certain tenders are covered by automatic indexation.
- Regulatory compliance: Certified installation, completed procedures, compliance with capacity thresholds … all prerequisites to be validated. For self-consumption with resale, it is recommended to initiate the grid connection procedure early and consult a qualified installer to optimise timing and photovoltaic connection cost.
In short, PV tariff indexation is not just a mathematical formula; it is a living mechanism, shaped by public policy choices, economic indices, and continuously adapted to sector developments.
Breakdown of indices making up the coef k for photovoltaics
The k coefficient (often called coef k or coefficient KN in regulatory documents) is not just a single figure; it is built from several economic indices regularly published. These indices are essential as they allow the purchase price of photovoltaic electricity to be adjusted in response to sector cost changes and context.
Labour cost index (ICHTrev-TS)
The ICHTrev-TS index (Hourly Labour Cost Index, revised for the whole of industry and market services) represents the trend in wages in industry, including construction. The role of this index is to take into account increases or decreases in the wage bill in the sector.
- Published quarterly by INSEE.
- Based on French industrial data.
- ICHTrev-TS directly affects the labour share in the overall cost of PV projects.
Industrial production price indices
Several industrial indices are used in the coef k formula. Each reflects a share of the current expenditure linked to the construction or operation of a photovoltaic installation:
| Component | Associated INSEE index | Main use |
|---|---|---|
| Aluminium | IndexAlu (price of aluminium) | Cost of panel structures and frames |
| Copper | IndexCu (price of copper) | Cost of wiring and electrical systems |
| Steel | IndexAcier (price of steel) | Supports, framework, fixing |
| Transport | IndexTransport | Panel delivery, logistics |
Each of these indices is analysed over a rolling period to adjust the variation of the coefficient, considering raw material market fluctuations. Adjustment takes into account the sensitivity of actual costs experienced by businesses in the sector.
Long-term interest rate index
This final index, sometimes called « TauxDette » in regulations, reflects the cost of financing photovoltaic projects on the market. Most installations are not financed from equity but by borrowing.
- Measurement used: average long-term interest rates, generally over three months, with a two-quarter lag.
- Objective: ensure that projects remain viable even if bank rates rise.
The detailed make-up of coef k, and the weighting of each of these indices in the formula, is designed to ensure that remuneration for photovoltaic electricity remains aligned with the sector’s economic reality. Having an adjusted coefficient is especially important in areas where feed-in rates are segmented by power thresholds, as shown by the new tariff-setting rules in ZNI.
In summary, coef k is based on three main families of indices: labour costs, industrial material prices and financing rates. Their evolution ensures a kind of financial balance for project promoters, season after season.
Methodology for calculating coef k for photovoltaics
The calculation of the k coefficient, which indexes the purchase tariffs for photovoltaic installations, uses a transparent and controlled method. This mechanism adjusts solar electricity buyback prices in line with several economic indices, to reflect the actual cost increases experienced by producers. Let’s look step by step at the methodology used to determine this coefficient.
Official indexation formula
The coef k calculation formula is based on changes in a basket of indices published by INSEE and other official sources. For most powers between 100 and 500 kWc, the formula is generally as follows :
K = K(n+2)/K(n)
where « n » represents the reference tariff quarter. This method helps smooth the short-term impact of fluctuations.
For example, if in Q2 2025 the value of coef k is 1.267 and in Q3 it rises to 1.290, then the change in coef over the period will be:
Change in coef k = 1.290 / 1.267 = 1.018
which is a 1.8% increase.
Choice of reference indices
The basket of indices used for tariff indexation typically includes :
- Labour cost index (ICHTrev-TS, industrial sector)
- Industry production price index (for France and the European Union)
- Long-term interest rate index
Each index tracks a specific cost for producers. The aggregation of these indices gives a realistic picture of costs on which the feed-in tariff should be based, as detailed in the indexation coefficient K for wind power.
The careful selection of the indices keeps a fair relationship between the feed-in tariff and the actual cost price of photovoltaic electricity produced, while avoiding excessive volatility linked to the economic context.
Frequency of updates
The coefficient k is updated at regular intervals — usually each calendar quarter. However, some contracts provide for annual updates based on values published at a fixed date. Key stages:
- Gather the index values at the reference date.
- Calculate the relative change between the reference period and the update period.
- Publish the new coefficient and apply it to tariff-setting.
| Quarter | Previous coef k | Current coef k | Change (%) |
|---|---|---|---|
| Q2 2025 | 1.267 | 1.290 | +1.8 % |
| Q3 2025 | 1.290 | 1.305 | +1.1 % |
Regular adjustment ensures that the profitability of installations closely tracks actual expenses, thus limiting speculation or chronic under-remuneration.
In addition, it may be useful to consider the inclusion of the photovoltaic production coefficient, since attention to these various parameters determines the credibility of the purchase system. This framework, though structured, is flexible enough to ensure tariffs match what’s happening on the ground and sectoral trends.
Practical application of indexation via coef k according to installed capacity
Adjustment for installations from 9 to 100 kWc
For photovoltaic sites with a capacity between 9 and 100 kWc, the k coefficient plays a key role in tariff changes. Its application is based on several criteria:
- Annual tariff indexation is systematic throughout the contract period (20 years); it cushions the effect of inflation on running costs.
- The indexation formula mainly relies on economic indices such as ICHTrev-TS and index FM0ABE00000.
- Tariff updates usually take effect annually, ensuring a degree of stability for operators.
Degression coefficients, for their part, are activated according to the volume of new applications each quarter. This alters tariff trends across time, more or less markedly depending on the PV marketplace.
In practice, anticipating when to submit a connection application can significantly influence the tariff applied across the contract.
Specific rules above 100 kWc
As soon as installed capacity exceeds 100 kWc, special rules govern indexation:
- Combined indexation applies, blending several indices: labour costs (ICHTrev-TS), industrial production price index, debt rate, and others.
- There is a remuneration cap defined as installed capacity multiplied by a duration of 1,100 hours. Beyond this, energy remains remunerated, but at a reduced, non-indexed tariff.
- Updates remain annual for the main tariff, but the application of KN or BN coefficients introduces a fine adjustment depending on economic variations.
Here is a representative example, taken from the year 2025, for full or surplus sale:
| Capacity range | Feed-in tariff (c€/kWh) | Annual ceiling (h) | Tariff above ceiling (c€/kWh) |
|---|---|---|---|
| ≤ 500 kWc | 8.86 to 10.52 | 1,100 | 4.00 |
This modular approach is suited to the wide variety of projects and encourages optimising installation size to maximise the volume paid at the full rate.
Cases of installations below 9 kWc
For smaller installations under 9 kWc, the process is simplified:
- The buyback tariff benefits from automatic indexation, based on fewer indices.
- These installations are not subject to quarterly fluctuations tied to marketplace dynamics: tariff stability is paramount.
- Administrative requirements remain minimal, as do the rules regarding application submission and contracting.
Small project holders thus benefit from a secure environment, conducive to individual or family investment.
The variation in indexation according to capacity allows the rules to be adapted to each market segment. Installed capacity and tariff structure go hand in hand to reflect the true cost and associated challenges.
To size capacity correctly and avoid overspending or under-sizing, it is best to assess energy needs and grid connection requirements. Useful advice is offered in this resource on Enedis connection power.
For projects above 500 kWc, there are other remuneration schemes, as outlined on the page covering the contract for installations over 500 kWc.
Influence of reference periods and calendar quarters on coef k
The PV indexation system based on coef k depends on distinguishing the quarter when the Complete Connection Request (DCR) is submitted from the calendar quarter applied to the actual tariff. The calendar quarter is not chosen at random: it is strictly linked to the submission period of the application.
| Start and end of reference quarter | Corresponding calendar quarter |
|---|---|
| 1 December – 28/29 February | 1 January – 31 March (Q1) |
| 1 March – 31 May | 1 April – 30 June (Q2) |
| 1 June – 31 August | 1 July – 30 September (Q3) |
| 1 September – 30 November | 1 November – 31 December (Q4) |
Thus, a DCR made in March falls under the second calendar quarter, and so on. This determines the purchase price allocated to a given period. To delve deeper into this correspondence mechanism, it may be useful to consult the logic of taxation tariffs and associated arrangements.
The exact time when you submit your application or commission your PV installation plays a direct role in setting the purchase price via coef k:
- Commissioning just after the close of a quarter can lead to the application of new economic indices, sometimes less favourable.
- Tariffs are set based on indices published and fixed at the start of each calendar quarter.
- Bringing forward or delaying an application changes the reference index base and thus the coef k applied.
- For small installations under 9 kWc,
tariffs no longer change each quarter since March 2025.
Choosing when to submit an application can have measurable effects on profitability, especially when a sharp change in indices is expected soon.
Legislative changes sometimes introduce transitions that change how reference periods and calendar quarters affect coef k. When a new decree comes into force:
- The indices used for the calculation change their reference value or scope.
- DCRs submitted before/during the change find their tariffs set under the old or new decree, sometimes retroactively.
- The reference period for coef k calculations may be changed, involving new indices or temporary correction coefficients.
- Keeping a close eye on regulatory news, such as the current tariff decree since 2021, is crucial to anticipate potential impacts on the tariff obtained.
These adjustments and crucial transition periods raise many questions for project owners or installation managers, especially during times of sharp price or interest rate changes. Aligning the administrative timetable with the indexation calendar thus becomes a vital factor in optimising the value of PV production.
Annual and quarterly update process for tariffs indexed to coef k
Annual update over the duration of the purchase contract
Each photovoltaic energy purchase contract generally covers twenty years. During this period, the purchase price initially set is not fixed: it is revised annually through an indexation mechanism based on the k coefficient. This ensures that the feed-in tariff remains appropriate to changing economic costs affecting the photovoltaic sector. The annual adjustment is based directly on published reference indices and official methods that ensure long-term coherence for both producer and buyer.
By securing an annual update, the PV producer protects their investment from unexpected market changes and limits financial risks from structural cost increases.
Calculation based on indices published by INSEE
The k coefficient is mainly based on the variation in several economic indices regularly updated by INSEE. These include:
- ICHTrev-TS, reflecting labour cost
- Production price indices (aluminium, copper, steel, transport)
- Long-term interest rate index
The calculation of the k coefficient reflects changes in these indices between the reference date set by the last tariff decree and the contract revision point. For illustration:
| Index | Reference Value | Updated Value | Weighting |
|---|---|---|---|
| ICHTrev-TS | 129.2 | 131.7 | 25% |
| FM0ABE production price | 127.7 | 130.2 | 20% |
| IndexAlu | 149.5 | 152 | 10% |
| IndexCu | 159.6 | 166 | 10% |
| IndexAcier | 199.0 | 203 | 10% |
| IndexTransport | 234.8 | 240 | 15% |
| TauxDette | 0.0165 | 0.0171 | 10% |
This table gives an overview of the factors used, but the exact formula and coefficients, as explained in the structure of indices, remains an essential aspect to understand in any calculation.
Making adjustments in the event of economic deviation
If the measured evolution of the indices shows a significant gap (rise or fall) compared to what was anticipated, the purchase price is adjusted upward or downward. This adjustment mechanism, quarterly or annual depending on the capacity and the applicable rule, plays a direct role in the producer’s remuneration. Here is how it works:
- Retrieve the updated value of each index at the review date.
- Calculate coef k using the official formula, with the weighting for each index.
- Apply coef k to the initial feed-in tariff to calculate the new tariff.
If a period shows high volatility (such as a sharp rise in material prices or financing cost), this indexation system ensures a degree of fairness, automatically adjusting tariffs to match economic reality.
To find out all the payment procedures, TURPE calculation or what happens in the event of a dispute or adjustment, the CARD contract offers a useful and up-to-date summary for all connected producers.
Concrete examples of calculating a PV feed-in tariff with coef k
Case study for a 100 kWc installation
Take a 100 kWc photovoltaic installation connected and commissioned in the third quarter of 2025. The initial purchase price, obtained in the second quarter of 2025, is 11.26 c€/kWh. The final tariff then undergoes various adjustments accounting for both degression and indexation via coef k (also called KN):
- Reduction via coefficient BN, representing a typical decrease of 0.25% per quarter (here, B15/B14 = 0.9975)
- Application of the KN change (K15/K14 = 1.290/1.267 or +1.78%)
- Applied degression coefficient, based on connection application volumes: for this quarter it’s 0.945 (-5.5%)
| Items | Value |
|---|---|
| Purchase price N-1 | 11.26 c€/kWh |
| BN (down 0.25%) | x 0.9975 |
| KN (up 1.78%) | x 1.018 |
| Degression (down 5.5%) | x 0.945 |
| Final result | 10.81 c€/kWh |
This mechanism encourages you to pay close attention to when your grid connection application is submitted, as each quarter affects the effective tariff applied for 20 years.
Impact of a change in an index on the final tariff
The coef k indexation is based on several economic indices (wages, industrial costs, interest rates). A rise in the main INSEE index impacts the tariff almost immediately. Here are some typical situations:
- An increase in the wage index helps raise coef k, thus the purchase tariff
- A decrease in industrial production costs brings coef k down
- The long-term interest rate affects investments and tariff adjustments
| Scenario | KN change | Effect on tariff |
|---|---|---|
| Wage indices up (+2%) | x 1.02 | Rise |
| Industrial costs down (-1%) | x 0.99 | Fall |
| Long-term rates up (+0.5 point) | Variable | Depending on weighting |
Producers must therefore keep a regular eye on official index publications.
Effects of delayed commissioning
A delay in commissioning a photovoltaic installation can affect the final tariff due to the KN+P/KN rule. Depending on the number of quarters between the complete connection request (DCR) and the actual commissioning date:
- If commissioning coincides with the DCR quarter: KN/KN = 1 (no impact)
- One quarter delay: KN+1/KN (usually a slight decrease or increase depending on circumstances)
- Two or more quarters: KN+2/KN (risk of significant decrease)
Keeping on schedule for commissioning is crucial to preserve the expected profitability of the PV project.
For more on the role of capacities and their impact on connections, it is useful to consult the distinction between contracted power and connection power in this article on the concept of power.
Adjusting coef k in response to economic and regulatory changes
Adjustment of coef k in the photovoltaic sector is never static. Its evolution reflects the need to react quickly to market changes, be they driven by material prices, bank rates or regulatory amendments. The goal is to maintain a balance between long-term economic viability and the public interest in renewable energy development.
Taking account of raw material price trends
Sudden movements in the aluminium, copper or steel markets can unbalance a project’s budget. The coef k then provides a real means to adapt to rising production costs. The calculation of coef gives significant weight to a number of specific indices:
- IndexAlu for aluminium
- IndexCopper for copper
- IndexSteel for steel
- IndexTransport, as logistics also impacts the final price
For example, on 1 November 2022:
| Index | Value |
|---|---|
| IndexAlu0 | 149.5 |
| IndexCu0 | 159.6 |
| IndexAcier0 | 199.0 |
| IndexTransport0 | 234.8 |
These figures directly reflect the economic reality of projects and thus secure the business model of operators.
Effects of changes in financing costs
The financial balance of a PV project depends heavily on its funding. Rising interest rates change the expected return. The coef k — via the TauxDette index — takes this major issue into account. For example, a 1% rise in the interest rate is offset by a 4% increase in coef k to preserve project profitability.
Practical reminder:
- TauxDette0 on 01/11/2022 : 0.0165 (i.e. 1.65%)
- Calculation is based on the average for quarter N-2, for stability
This system prevents higher debt costs from pushing smaller producers out of the market at difficult times.
Changes linked to successive tariff decrees
The regulatory timetable is not linear. Tariff decrees or laws may change the calculation formula or indices, sometimes from one quarter to the next. The main principles remain, but the parameter details may change — as happened with the amending decree of 8 February 2023, which set new references for the KN coefficient and INSEE indices.
For each change, producers must:
- Use the new official calculation formula
- Update INSEE indices and reference rates
- Adapt their budget forecasts in line with changes
Through successive adjustments, coef k serves as a safety mechanism for contract economic balance over 20 years, even in a changing regulatory environment.
Similarly, tariff adjustment mechanisms are found in other energy sectors, such as storage management for EDF service providers, showing that tariff flexibility is now essential in energy.
Specifics of coef k for full-sale and surplus-sale models
The indexation of the feed-in tariff via the k coefficient (or coef k / KN) applies equally to full sale and surplus sale, but some rules and impacts clearly differ according to the chosen model.
Differences in the application of indexation
- The coef k indexation mechanism works on the guaranteed feed-in tariff for both models (full and surplus).
- Tariff structures are set per quarter, with the date of the grid connection request determining the initial tariff.
- There is a remuneration ceiling based on energy generated during 1,100 hours at full installed power: above that, remuneration drops to 4 c€/kWh, unindexed.
- Indexation is strictly applied within this ceiling. Any surplus above does not benefit from indexation (see the production declaration and adjustments to the invoice for sale to EDF OA).
Respective benefits of both mechanisms
- Full sale:
- Secures all energy produced at an indexed rate.
- Administrative simplicity: all is exported to the grid.
- Often chosen for medium and large-scale arrays (>36 kWc).
- Surplus sale:
- For those who consume some of their own electricity.
- Portion not consumed is sold at the indexed tariff.
- Attractive for small systems that reduce their bill through self-consumption.
| Sale type | Coef k applies | Energy self-consumed | Tariff indexation ceiling |
|---|---|---|---|
| Full sale | Yes | No | Yes |
| Surplus | Yes | Yes | Yes (on surplus) |
Limits for exceeding the remuneration ceiling
- The purchase tariff indexed by coef k is capped: if annual production exceeds « capacity x 1,100h », the producer is only paid at the unindexed tariff of 4 c€/kWh thereafter.
- This rule applies to both full sale and surplus sale.
- This protects the system against excessive profitability and controls public expenditure.
Even when the indices included in coef k rise sharply, profits are never unlimited: the ceiling guarantees remuneration model stability.
In summary, the indexation logic for full and surplus sale via coef k remains similar, but the management of self-consumption and remuneration cap really distinguishes the two options.
Obligations, guarantees and payment arrangements linked to coef k indexation
Security deposits and conditions for projects >100 kWc
Photovoltaic installations above 100 kWc must meet several specific conditions to benefit from indexation based on the k coefficient. Firstly, a financial security deposit is usually required from the producer to guarantee project completion. This acts as security for the purchaser in the event of non-performance or delay.
- The amount of security depends on system size and capacity.
- It must be paid at the signing of the purchase contract.
- If the project is abandoned or the schedule not met, the deposit may be withheld.
To receive payment at indexed tariffs, actual grid connection and regulatory compliance are always checked.
Scrutiny of the project owner’s financial solidity is a key step, with regular checks during the whole contract period.
20-year payment guarantees
The law requires the tariff indexed to coef k to be guaranteed for twenty years from the commissioning date. This contractual security encourages investors to commit for the long term.
Main associated arrangements:
- The initially agreed price is revised annually via indexation according to INSEE-published indices.
- The producer is assured of payment for the full contractual period, subject to operational compliance.
- Transparency over the tariff calculation method (available on the decree of 6 October 2021) prevents future disputes.
The regulatory framework protects producers while ensuring suitable modulation of the indexed tariff.
Payment deadlines and processes using indexation
Coef k indexation involves specific payment arrangements, set by regulations:
| Stage | Usual timescale | Special features |
|---|---|---|
| Indices transmission | Once a year | Published by INSEE |
| Tariff calculation and billing | Quarterly or annual | Depending on installation type |
| Payment after invoicing | 30 to 45 days | Reflects indexation |
Payments are systematically revised each reference period. For systems already running or commissioned after a regulatory change, payment rules may differ slightly, especially for the initial bonus paid at the start of the contract (detailed for <36 kWc systems on initial bonus entitlement).
- Issue of an invoice taking account of indexation.
- Automatic check for compliance with reference indices.
- Adjustment of payment according to economic changes for the relevant quarter.
Indexation protects against inflation, but strict paperwork and deadlines remain imperative to trigger payment.
Understanding these obligations and guarantees enables project owners to secure their long-term profitability, taking account of regulatory and economic developments throughout the lifetime of the PV purchase contract.
It’s important to understand how the k coefficient influences indexation. With this system, your obligations, guarantees and payment process are clear. For full details or to ask a question, visit our website. You’ll find straightforward explanations and help to better understand your contracts!
Conclusion
In conclusion, the calculation of photovoltaic feed-in tariff indexation, especially via the KN coefficient, may seem complex at first. In reality, it is based on clear rules and well-defined economic indices. Every quarter, tariffs change to reflect real market conditions and sector costs. This guarantees a measure of stability for project developers while avoiding excessive profitability. If you plan to invest in solar, it is important to keep abreast of these developments and to check the latest regulations. If in doubt, do not hesitate to consult a professional or the official resources. You can then move forward with confidence, with a clear view of the tariff terms that will apply to your system.
Frequently Asked Questions
What is the k coefficient in the indexation of photovoltaic feed-in tariffs?
The k coefficient is a figure used to adapt the purchase tariff for solar electricity. It takes account of several economic indices such as production costs, salaries and interest rates. This ensures the tariff remains fair even if prices change.
Why are photovoltaic electricity feed-in tariffs indexed?
Indexation is used to adjust the purchase price to take into account changes in the costs of producing solar electricity. This ensures producers do not lose money if material or wage costs increase.
How is the k coefficient calculated?
The k coefficient is calculated from several official indices published by INSEE, such as the industrial wage index, the price of aluminium or copper, and interest rates. These indices are updated regularly to reflect market realities.
Does every solar electricity producer benefit from indexation by coef k?
No, only producers with installations above 9 kWc are affected by indexation with coef k. For installations of 9 kWc or less, the tariff remains fixed and does not change from quarter to quarter.
Does the commissioning date of the installation affect the price paid?
Yes, the commissioning date is important. The later the commissioning compared to the grid connection application, the more the purchase price may change. It is therefore advisable to commission the system quickly after the grid connection application.
What are the differences between full sale and surplus sale regarding indexation?
With full sale, all the electricity produced is sold and the tariff is indexed with coef k. For selling the surplus, only the electricity not used is sold, but the purchase price is also indexed in the same way. However, there are remuneration ceilings not to be exceeded.
What happens if economic indices change a lot from one year to the next?
If the indices move significantly, the k coefficient will adapt and the feed-in tariff is adjusted up or down. This protects producers against big changes in material costs or interest rates.
How long is the tariff indexed with coef k guaranteed for?
The feed-in tariff indexed with coef k is guaranteed for 20 years, which ensures financial stability for the producer throughout the contract.
