Case Study: Real Madrid – Santiago Bernabéu Stadium

Lighting Invention for a Stadium Like No Other

Introduction

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Challenge

Real Madrid’s ambitious stadium upgrade transformed the Bernabéu into a multifunctional venue, capable of hosting high-calibre sports and non-sporting events. A retractable roof and underground pitch storage maximised usability — but reduced natural light and airflow, making pitch maintenance difficult.

To ensure year-round turf quality, a 30-metre-deep underground greenhouse was built. Rhenac’s CLS lighting solution became the cornerstone of this setup, delivering precise light, heat, and environmental control in a fully automated system.

Grass only grows when light intensity, nutrient levels, moisture and temperature are perfectly balanced. Rhenac’s intelligent monitoring unit ensures constant measurement — and real-time response if needed.

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Project Objectives

• Ensure year-round, competitive turf quality
• Enable underground storage of the pitch without compromising turf health
• Reduce maintenance time, energy use, and operating costs
• Implement a remotely controlled, automated lighting system
• Provide operations teams with greater flexibility and control

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Solution

Rhenac Sports LED used its long-standing partnership with the Technical University of Munich to develop a scientific, data-led approach to underground pitch care.

The CLS system was engineered in-house in Germany with:

• 12 years of research on light-plant interaction
• Programmable, zonal lighting
• Pre-assembled units for quick deployment
• Patented, in-house LED lamps
• Sensor-controlled digital monitoring for real-time feedback
• Modular architecture for scalable installation across venues

Installation began immediately after the 2022–23 season, with six specialised teams working throughout the summer to meet the deadline.

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Technology Imitating Nature

The Bernabéu’s new architecture and busy event calendar reduced natural light exposure and recovery time for the turf. CLS technology addressed this by replicating sunlight underground.

Unlike single-spectrum grow lights, Rhenac’s CLS can reproduce any light spectrum — from UV to infrared — and tailor it by turf zone to support:

• Germination (red light)
• Root growth (blue light)
• Disease resistance, drying, and stress reduction

CLS is a cold light source that avoids heat stress. Infrared warmth is used only when biologically necessary. Sensor data on temperature, soil moisture, nutrient content and climate is logged, analysed, and used to auto-adjust lighting, heating, irrigation, and fertilisation — or enable groundsmen to intervene remotely. The result is a self-regulating lighting ecosystem that supports all grass species throughout the season.

During tournaments where the pitch must remain inside the stadium, mobile CLS units are used to maintain optimal grass conditions. These mobile rigs use the same light spectrum as the hypogeum system to ensure the turf receives consistent lighting, avoiding stress and enabling seamless continuity of turf maintenance during transitions.

Groundsman’s Perspective

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Results

• Turf remains in the hypogeum for extended periods without deterioration
• Events like concerts can run without compromising pitch quality
• Mobile CLS rigs supplement lighting when pitch is not underground
• Denser root structure ensures elite-level playability
• Grounds teams can manage the system fully remotely
• Sustainability gains: reduced water, energy, and resource usage

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Conclusion

The integration of Rhenac Sports LED’s CLS technology into the Santiago Bernabéu stadium marks a world-first in intelligent turf lighting. It ensures consistent pitch quality — even when stored underground — and represents the future of sports turf management: automated, efficient, and data-driven.

Rhenac sets a new global benchmark for sustainable, intelligent turf care in multifunctional venues.