Solar Sheep Grazing Case Study: French Evidence

Last updated: November 2026

A useful sheep-grazing case study needs a named site, published methods and honest limits. The French example comes from INRAE, CVE and Statkraft, who followed a flock at a working solar plant for two years. It tells you a lot about animal welfare and handling. It tells you nothing about the cost or return of an unnamed five-megawatt project.

SurgePV publishes this post and sells solar design software. This is a secondary summary of published research, not SurgePV fieldwork or a customer story. The planning guidance after the study summary is editorial advice for another site, not measured results from the studied plant.

The Documented French Study

The INRAE animal-welfare report covers CVE’s solar plant at Bissey-sous-Cruchaud, which has been kept by eco-grazing since it started operating in 2021. Researcher Véronique Deiss led the animal-welfare work.

The report says earlier studies covered only weeks or months and did not assess feeding, housing, health and behavior together. This one ran for two years. The April 2024 INRAE announcement summarizes the findings but gives a flock of 24 ewes, while the report’s methods say 20. Keep each count attributed to its document, and read the report for the method.

What the Study Found

The report reaches five main findings. Each one describes this plant, not sheep farming under solar in general.

Heat stress was lower under the panels. The researchers used a heat load index (HLI), which combines temperature, humidity, wind and solar radiation. In August 2023, between 10:00 and 17:00, the index showed marked stress in bare and between-row zones, while under the panels it never went beyond moderate stress. Light-sensor data showed the ewes sheltering under panels in hot periods. Panels did not remove the stress: in May 2022 the index showed marked stress in every zone from 10:00 to 19:00.

Daily behavior did not change. On average the ewes spent 428 minutes a day lying and 1,012 minutes standing, in line with the normal ruminant cycle of feeding, rumination and rest. The flock stayed synchronized, and no ewe was isolated.

Grass grew taller under the panels at this site. In the protected sample plots on the better southern part of the plant, average grass height in May 2022 was 12 cm under the panels and 10 cm between rows. In July 2022 it was 6 cm and 3 cm. The northern part of the plant grew little grass anywhere, with visual estimates under 5 cm throughout. Forage analysis found more protein and slightly better digestibility under the panels, and more fiber between the rows.

Panels did not affect parasites, anemia or cleanliness. Fecal soiling scores stayed between 1 and 2 and no diarrhea was seen. One check in late spring 2022 found 5 to 6 ticks per ewe, absent at the next check. One ewe was found dead in 2022 and was not autopsied, so the report offers no cause.

Injuries were the problem. In early 2022 the flock was gathered with dogs for care and sensor fitting. That caused stress, flight behavior and some serious injuries, including one ewe that needed veterinary treatment and was removed from the plant. From late 2022 the plant was fenced into zones and the ewes were drawn in with feed, and no injuries followed.

The report also measured noise. At 1 m from an inverter at 13:00 it recorded 71 dBA in June 2023, 72.4 dBA in August and 61.5 dBA in October. Ewes were never seen near inverters at full output, though those areas were grazed, and the author suggests insulating inverters or placing them at row ends.

What INRAE Recommends for Layout

The report’s conclusion turns the findings into design advice. It advises against dogs for gathering in a solar plant. It recommends fewer supports, fewer protruding supports, a minimum structure height of 80 to 90 cm, a park divided into several zones, and a panel-free zone in the middle of a row. It also suggests isolating inverters or placing them at row ends.

What Transfers to Another Pasture?

The case gives a reason to investigate how animals use a solar site. It does not show that every pasture should host PV. A proposed layout needs review with the farmer and appropriate agricultural, livestock, veterinary, structural, electrical and safety specialists.

INRAE’s broader agrivoltaic research overview describes different pasture responses: panels can help under dry conditions, while shading may reduce production where light limits more productive pasture. Transfer depends on climate, vegetation, management and geometry.

Start with the agricultural problem. What does the farm need to maintain or improve? What would be unacceptable? Put those questions beside the electricity objective before selecting a layout or quoting a return.

Separate these decisions:

• Whether the proposed activities fit the applicable legal framework.
• Whether the layout permits acceptable animal movement, handling and maintenance.
• Whether suitable observations support the intended agricultural effect.
• Whether the electricity model represents the actual equipment, geometry and operating conditions.
• Whether the farmer, landowner and electricity operator understand their responsibilities and separate cash flows.

A positive answer to one does not settle the others. Grazing activity does not by itself prove legal agrivoltaic status, acceptable returns or a biodiversity benefit.

Design Around the Farming Operation

Create a joint site record. Identify the actual flock, farming calendar, water access, handling areas, machinery, terrain, vegetation and responsible people. Note which items were observed, supplied by the farmer, modeled or still open.

Do not choose a universal panel height or sheep-per-hectare ratio from another project. The 80 to 90 cm figure in the INRAE report is that plant’s recommendation. Assess your animals and working practices against your own clearance envelope, supports, fencing, access and equipment. For trackers, review relevant positions and maintenance or failure states, because clearance in one position does not guarantee clearance in all conditions.

This is a planning aid, not an installation specification. The responsible reviewers should set the actual acceptance criteria and stop conditions.

Keep Energy Models Separate from Agricultural Observations

A PV model estimates electricity from weather, geometry, equipment and loss assumptions. It does not measure forage or animal welfare. A grazing observation likewise cannot tell you electricity yield, inverter compatibility, structural suitability or lender acceptance.

The agrivoltaic design guide and bifacial design guide cover related modeling questions. Check each assumption against the actual project and do not import a percentage gain because another site reports one.

Keep DC nameplate capacity separate from AC equipment capacity. Label modeled versus measured production and note periods, meter boundaries, missing data, availability and curtailment. A gap between estimate and actual does not isolate a grazing, soiling or shading effect.

Illustrative consistency check, not specifications of the French research site: 14,000 modules at 360 Wp total 5,040,000 Wp, or 5.04 MWp DC. Eight inverters rated at 630 kW AC total 5.04 MW AC. Those ratings give a DC/AC ratio of 1.00, not 1.20, so a different ratio needs a different rating basis, equipment quantity or accepted output limit, each with a source.

Similarly, 7,000 MWh equals 7,000,000 kWh. Multiplying that hypothetical energy by an assumed 0.087 euro per kWh gives 609,000 euros before adjustments. This is arithmetic, not a tariff, a measured yield, a contract or a profit. A forecast needs the actual compensation terms and project evidence.

Define Monitoring Before Claiming Benefits

Specify the question, comparison basis, observation locations, dates, instruments, missing-data treatment and reviewers before collecting measurements. Photographs of animals under panels cannot replace a method. The INRAE report is a good model: it fixed its sensors, observation periods and health protocol up front.

Do not interchange sheep count, grass height, dry-matter production, animal weight and farm income. Keep the denominator and period for every measure. Weather, feed, flock composition, health management and grazing practice can all affect comparisons.

Biodiversity, soil-moisture and avoided-emissions claims need their own evidence. An animal-welfare study does not cover them. A carbon calculation must state generation, displacement, life-cycle and time assumptions, because grazing is not automatically carbon-neutral.

Check French Legal Status from Official Sources

Checked November 4, 2026: Energy Code Article L314-36, in force since 12 March 2023, defines an agrivoltaic installation as one that durably supports agricultural production on an agricultural plot. It must directly provide at least one of four services to the plot: improved agronomic potential, adaptation to climate change, protection against hazards, or improved animal welfare. It cannot qualify if agricultural production is not the main activity on the plot, or if the installation is not reversible. A photograph or voluntary label cannot establish compliance.

The April 2024 decree introduced implementing provisions for agrivoltaic development and PV on agricultural, natural or forest land. Obtain the current consolidated provisions and project-specific advice before relying on conditions, monitoring duties or an approval path.

Review land tenure, planning, environmental requirements, agriculture, utility connection, insurance, tax and agricultural-support eligibility with responsible advisers and authorities. Do not assume an association certificate guarantees permission, tariffs or Common Agricultural Policy payments.

Use the CRE tender documents and the actual award or contractual route as compensation evidence. A historical rate or an assumed universal agrivoltaic premium is not a new project’s price.

Keep the Farmer, Landowner and Solar-Company Accounts Distinct

Identify whether a financial model concerns the farm, the landowner, the electricity project or a consolidated view. Attribute revenue, costs, financing, taxes and contractual payments to the correct party.

Rent paid by the project company is a payment for that company and a receipt for the landowner. In a properly scoped consolidated view of both, eliminate the internal transfer, since it is not additional external revenue. The farmer’s land income is not automatically the solar company’s electricity income.

Use consistent periods, price assumptions, cost boundaries and responsibilities when comparing alternatives. Define the agricultural baseline. Revenue per hectare, operating profit, net income and return on invested capital are different measures.

Evaluate supported scenarios with solar financial modeling, validated inputs and appropriate financial review. Do not report IRR, LCOE, payback or finance approval without the cash-flow method and evidence. Higher combined revenue may also involve more capital, obligations and risk.

Evidence to Request Before Publishing Another Case

Obtain permission for named people, organizations, images and data. Identify the source author, operating site, equipment basis, dates and publisher relationship. Separate operator-reported information, independent research and editorial interpretation.

For an investment case, request dated costs, contractual compensation, energy records, agricultural results, operating costs, entity structure and calculation methodology. For a welfare case, ask for the protocol, observation periods, outcomes and limits. Do not fill missing fields with plausible figures.

Readers should understand what happened, what supports it, which decision it can inform and what remains unknown. A source-linked case with clear limits is more useful than an unsupported success story.

Carry Accepted Conditions into the Design Workflow

SurgePV’s design workflow and shading analysis cover 3D roof modeling, array layout, shading and energy-yield modeling. Check the required inputs and outputs for a dual-use site in a demo, using a representative sanitized project with your equipment, geometry and revisions.

Software cannot supply missing agricultural observations, certify welfare, settle French legal status or approve the project. Carry the accepted agricultural and technical conditions into the model, and leave the decisions with the responsible reviewers.

Planning a dual-use site? Book a SurgePV demo and bring your layout, clearance and evidence requirements.

Frequently Asked Questions

What does the French sheep-grazing solar study show?

A two-year INRAE, CVE and Statkraft study at the Bissey-sous-Cruchaud plant found that panels limited heat stress for grazing ewes and did not change their daily activity pattern. It also recorded injuries during early dog-assisted gathering. The results describe one site and cannot set stocking rates, yield or returns elsewhere.

Does sheep grazing make a French solar project agrivoltaic?

No. Grazing alone does not give a project agrivoltaic status. Article L314-36 of the Energy Code requires that agricultural production stays the main activity on the plot, that the installation is reversible, and that it delivers at least one listed agricultural service, such as improved animal welfare.

What panel height is suitable for sheep grazing under solar panels?

The INRAE report recommends a minimum height of 80 to 90 cm for the panel structure at this kind of site, plus fewer protruding supports and a panel-free zone mid-row. Your own minimum depends on the flock, handling, machinery and, for trackers, every operating position.

What does a five-megawatt sheep-grazing solar project cost or earn?

The French study does not publish costs, energy yield or returns, so it cannot answer this. Build the figure from dated equipment quotes, a documented compensation route, measured or modeled energy and the farm’s operating costs. Label any illustrative arithmetic separately from contracted outcomes.

Do sheep benefit from shade under solar panels?

In this study, yes, partly. Ewes sheltered under panels in hot periods, and the heat load index stayed lower under panels than in bare or between-row zones. In May 2022 the index still showed marked stress in every zone from 10:00 to 19:00, so panels reduced the stress without removing it.

Does grazing under solar panels harm sheep health?

The INRAE report found no effect of the panels on parasites, anemia or cleanliness. Injuries were the exception: early dog-assisted gathering caused stress and some serious injuries, including one ewe that needed veterinary treatment in 2022. Injuries stopped after the site was fenced into zones and the ewes were gathered with feed.

How should farm and solar revenues be compared?

Compare them only on the same entity, period and cost boundary. Keep the farmer, landowner and electricity operator separate, remove internal transfers such as rent in a consolidated view, and distinguish revenue from operating profit, net income and return on capital.