Pillar sub-scores
A pillar mixes what is endured and what is chosen; a grade is not the average of the pillars. Energy
Energy
●●●● Missing: PUE (announced energy efficiency), Waste-heat recovery — commitment.
Water
Water
●●●● Missing: Cooling technology + announced water volume.
Land & biodiversity
Land & biodiversity
●●●○ Missing: Ecological corridors (TVB), Site ground footprint, Avoid-reduce-offset (ERC) measures, Designated for urbanisation in a supra-municipal plan, Planning-document compatibility procedure under way.
Local impact
Local impact
●●○○ Missing: Announced jobs, Announced tax revenue, Observed level of opposition, Elected officials' position (voted facts only).
Transparency & governance
Transparency & governance–
“Rated C on site, but E on “Energy”.”
This site is among the 80% of the fleet connected to an already-saturated substation. Fleet figures →
This site is in France — the country's site index: C (55.9). See the country index →
What the environmental case file states
2023-03-10 · 27 pages · read the opinion (PDF)
Energy and heat
Grid connection voltage225 kVp.2
Des batteries électriques permettent d’attendre la mise en route des groupes électrogènes en cas de défaillance Le projet intègre également le raccordement au réseau de transport d’électricité par la création d’une double liaison souterraine 225 000 V, d’environ 1,4 km chacune, depuis le poste source RTE.
Data hall (IT) power120 MWp.9
Description technique du projet Le centre de données nécessite pour son fonctionnement « une alimentation électrique stable, permanente et fiable des salles informatiques » dont la puissance prévue est de 120 MW5.
Announced PUE1.4p.14
Il est rappelé que le PUE moyen des centre de données en France est de 1,8 et que celui attendu pour le projet est estimé à 1,4 qualifiant « d’élevée » la performance énergétique du projet d’après le dossier.
On-site photovoltaics (as reported)1612 m2p.15
En cours d’instruction l’ Autorité environnementale a été informée de l’installation de 912 modules de panneaux photovoltaïques en toiture sur une surface de 1612 m2.
Waste heat recoveryunder_studyp.14
Le projet prévoit la possibilité de valoriser la chaleur fat ale du site (p. 254), détaillée dans une étude de faisabilité pour la création d’un réseau de chaleur (annexe 11).
Water and cooling
Refrigerant (designation)3 values
R513A · R410Ap.106 Les fluides frigorigènes utilisés dans les refroidisseurs et condenseurs pour la production frigorifique sont le R513A et le R410A.
R1234zep.16De la même manière, sur la justification du choix des fluides frigorigènes utilisés dans les refroidisseurs air/ eau, l’étude d’impact indique (p. 254) qu’« en termes d’impacts environnementaux, l’utilisation du fluide HFO (R1234ze) est préconisée ».
Generators and fuel
Backup generators (count)27 groupesp.2
Afin d’assurer un fonctionnement en continu du centre de données en cas de défaillance du réseau électrique, 27 groupes électrogènes sont prévus pour suppléer à l’alimentation des installations.
Backup generator fueldomestic_fuel_oilp.9
Au nombre de 27, les groupes électrogènes seront alimentés en fioul domestique.
Fuel tanks (count)12 cuvesp.2
12 cuves enterrées de 100 m 3 chacune permettront de stocker la quantité nécessaire de fioul pour en assurer le fonctionnement pendant 48 heures.
Fuel tank unit volume100 m³p.9
12 cuves enterrées de 100 m3 chacune permettront de stocker la quantité nécessaire de fioul, de façon à garantir une autonomie électrique de 48 heures dans des conditions de fonctionnement à plein régime.
Backup autonomy48 hp.2
12 cuves enterrées de 100 m 3 chacune permettront de stocker la quantité nécessaire de fioul pour en assurer le fonctionnement pendant 48 heures.
Neighbourhood
Distance to nearest dwellings280 mp.7
Les premières habitations sont localisées à environ 280 m au nord-est du site, au sein d’un quartier résidentiel (p. 74).
Footprint and buildings
Building height18 mp.12
la hauteur maximale des bâtiments, qui ne peut excéder 18 m à l’acrotère, alors que le projet prévoit une hauteur de 30,85 pour les cheminées.
Measured noise
| Measure | Day | Night |
|---|---|---|
| Recorded levelsp.18 | — | — |
Les niveaux acoustiques en limites de propriété oscillent entre 57 et 61 dB(A) de jour (LAeq moyenné sur 7h-22h), et entre 50,5 et 57 dB(A) de nuit (LAeq moyenné sur 22h-7h).
State recorded in the impact assessment, before operation.
ICPE classificationICPE — the French regime that authorises, frames and inspects an activity liable to create a risk or a nuisance. Each number designates the activity concerned in the national nomenclature. Being classified does not mean being dangerous: it means being regulated, and therefore inspected.
- 3110Combustion — plants with a total thermal input ≥ 50 MW (IED directive)
- 2515Crushing and grinding of materials
- 2760Waste storage facility
Tracked indicators
| Indicator | Value | Reading | State | Source |
|---|---|---|---|---|
| Energy | ||||
| Local grid carbon intensity How much CO₂ is emitted to produce the electricity the site will consume, based on the regional grid. The lower the value, the better. | 17.6 gCO2e/kWh | Measured | RTE eCO2mix (données définitives) — France national CO2 intensity, 12-month mean 2025-07-30..2026-04-30 (17.6 gCO2/kWh, n=13196 half-hourly) — accessed 2026-07-30 | |
| Grid connection capacity / proximity How easily the site can be connected to the power grid: available capacity and distance to the nearest substation. | grid saturated at the connection point | Measured | Caparéseau (RTE S3REnR) — poste MONTJAY at 4.1 km: 0.0 MW available hosting capacity (updated 27/06/2026) — accessed 2026-07-14 | |
| Grid congestion / connection queue How congested the local grid is: the more saturated, the more the connection competes with other users. | critical local grid congestion | Measured | Caparéseau (RTE S3REnR) — poste MONTJAY at 4.1 km: 100.0% reserved-capacity fill rate (updated 27/06/2026) — accessed 2026-07-14 | |
| PUE (announced energy efficiency) The announced energy efficiency: total electricity used versus what actually powers computing. Closer to 1 is better. The lower the value, the better. | — | — | Not looked for yet We have not looked for this yet. It is dropped from the calculation and does not penalise the site. | — |
| Heat-network connectability Whether the site can valorise its waste heat via a district-heating network: distance to the nearest network and presence of a connection obligation (priority development perimeter). | heat network nearby | Measured | France Chaleur Urbaine (data.gouv, lov2) — réseau de chaleur le plus proche : 619 m (point→segment, Lambert 93) ; dans un PDP : non ; réseau classé : oui → proche (≤1000 m) — accessed 2026-09-30 | |
| Waste-heat recovery — commitment Operator commitment level to valorise the site's waste heat (delivered / signed contract / study / intention / none). | — | — | Not looked for yet We have not looked for this yet. It is dropped from the calculation and does not penalise the site. | — |
| Water | ||||
| Local water stress Water tension in the area: in an already water-scarce region, withdrawals weigh more heavily. | moderate water stress | Measured | VigiEau — drought-restriction status at point (accessed 2026-07-14) — accessed 2026-07-14 | |
| Water body status The ecological health of the affected river or aquifer, per the EU classification (from 'high' to 'bad'). | water body in moderate status | Measured | EEA WISE (WFD 2022) — water body FRHR99B 'L'Yvette du confluent de la Mérantaise (exclu) au confluent de l'Orge (exclu)': ecological status class 3/5 — accessed 2026-07-14 | |
| Basin withdrawal pressure How intensively water is already withdrawn from the basin: a heavily-tapped basin ill affords a new user. | low abstraction in the basin | Measured | Hub'Eau BNPE — commune 91661: 0.008 Mm3 withdrawn in 2011 (all uses, provisional pressure band) — accessed 2026-07-14 | |
| Cooling technology + announced water volume The cooling technology chosen and the water volume it will consume, as announced by the operator. | Not disclosed | — | Absent from the file We read the public file and the information is not in it. It counts as a zero in the grade. | Avis de l'autorité environnementale — lecture d'absence — accessed 2026-10-14 |
| Land & biodiversity | ||||
| Overlap / distance to protected areas How close the project is to protected natural areas (Natura 2000, nature reserves…). | protected natural area 1–5 km away | Measured | INPN / IGN API Carto — Natura 2000 & ZNIEFF overlap by distance ring — accessed 2026-07-14 | |
| Soil status (artificialized / natural / agricultural) What the land was before: already built (brownfield), natural, or farmland — sealing farmland or nature weighs most. | previously developed land | Measured | IGN API Carto GPU — PLU zoning 'UId' — accessed 2026-07-14 | |
| Ecological corridors (TVB) Whether the project severs a wildlife corridor (green-and-blue network). | Not disclosed | — | Absent from the file We read the public file and the information is not in it. It counts as a zero in the grade. | — |
| Site ground footprint The SITE's ground footprint in hectares — the land the project takes up (buildings, roads, parking, substation, retention basins), not the building print alone: the larger, the greater the land impact. The lower the value, the better. | — | — | Not looked for yet We have not looked for this yet. It is dropped from the calculation and does not penalise the site. | — |
| Avoid-reduce-offset (ERC) measures Measures to avoid, reduce or offset harm to soil artificialisation and biodiversity. (Heat recovery moved to E6/E7, Energy pillar.) | — | — | Not looked for yet We have not looked for this yet. It is dropped from the calculation and does not penalise the site. | — |
| Designated for urbanisation in a supra-municipal plan not scored · contextual fact Is the site designated for urbanisation in a planning document above the municipality? A contextual fact, published as such: it neither improves nor worsens the grade. | — | — | Not looked for yet We have not looked for this yet. It is dropped from the calculation and does not penalise the site. | — |
| Planning-document compatibility procedure under way not scored · contextual fact Is a procedure under way to make the planning document compatible with the project? A contextual fact: we follow the instrument, not the intention — the land status only changes the day the procedure completes. | — | — | Not looked for yet We have not looked for this yet. It is dropped from the calculation and does not penalise the site. | — |
| Local impact | ||||
| Municipality socio-economic profile The host town's social profile. A safeguard: a project must never improve its grade by locating in a vulnerable town. | municipality's social profile: favourable | Measured | INSEE Filosofi (via data.gouv) — commune 91661: median disposable income 29190 €/consumption unit — accessed 2026-07-14 | |
| Absorption capacity (project size vs municipality) The project's size relative to the town: a very large project in a small town disrupts more. The lower the value, the better. | 3.8869 MW per 1000 inhabitants | Announced | INSEE populations légales via geo.api.gouv.fr — Villebon-sur-Yvette (10291 hab.) ; puissance 40.0 MW (DCWatch ODbL, export 7dd5b5e9). Ratio MW/1000 hab, calcul déterministe — accessed 2026-07-14 | |
| Technological hazard / nearby Seveso sites The presence of hazardous industrial sites (Seveso) nearby, adding risk to the surroundings. | no technological-risk site on record within 5 km, to our knowledge | Measured | Géorisques — registre des installations classées (statut Seveso) qui ÉNUMÈRE : aucun établissement Seveso (seuil haut/bas) dans 5 km (site-de-contrôle A1 validé). — accessed 2026-10-06 | |
| Announced jobs The number of permanent jobs announced, relative to project size. More is better. The higher the value, the better. | — | — | Not looked for yet We have not looked for this yet. It is dropped from the calculation and does not penalise the site. | — |
| Announced tax revenue The tax revenue the project would bring to the town, as announced. | — | — | Not looked for yet We have not looked for this yet. It is dropped from the calculation and does not penalise the site. | — |
| Observed level of opposition The scale of observed opposition: appeals, petitions, mobilizations reported by the press. | Not disclosed | — | Absent from the file We read the public file and the information is not in it. It counts as a zero in the grade. | — |
| Elected officials' position (voted facts only) Elected officials' position as expressed by official votes only (council decisions), with no personal judgment. | Not disclosed | — | Absent from the file We read the public file and the information is not in it. It counts as a zero in the grade. | — |
| Transparency & governance | ||||
| Consultation / consent / governance (procedural proxies) The quality of the democratic process: public inquiry held, environmental authority opinion, appeals, CNDP referral. | — | — | Not looked for yet We have not looked for this yet. It is dropped from the calculation and does not penalise the site. | — |
| Documentation transparency / file availability How genuinely accessible the project's file is to the public: published studies, figures and commitments. | — | — | Not looked for yet We have not looked for this yet. It is dropped from the calculation and does not penalise the site. | — |
Operator response
The operator can send us a response about this datasheet. When a response is received and publishable, it appears here, clearly attributed and dated.
A factual error? Use “Report an error”, attaching a source or supporting document.
State of the available data
26 indicators tracked · 11 measured · 1 announced (unverified) · 4 absent from the file · 10 not looked for yet.
Grade history
Methodology 0.3.0 scoremydatacenter.org