Reliably temperature-controlled in sun, rain, and frost: PROTEMP Peltier system in a control cabinet with blue’Log plant controller for the regulation and monitoring of a photovoltaic system.

Outdoor control cabinets in ground-mounted photovoltaic systems are exposed to extreme environmental conditions: intense solar radiation, strong temperature fluctuations, as well as dust and moisture exposure. The key challenge is to reliably control the temperature of the sensitive electronics inside the control cabinet without compromising the enclosure’s protection rating.

This case study presents the successful use of the PROTEMP Peltier temperature control system 70 M Outdoor for control cabinet climate management. The control cabinet houses a blue’Log park controller from meteocontrol, which is used for regulating and monitoring a photovoltaic system. The system is complemented by a power quality analyzer for monitoring current and voltage values, network components for communication, and an uninterruptible power supply (UPS) for maximum operational reliability.

The optimal internal temperature of the control cabinet is between 5°C and 40°C – with ambient temperatures ranging from –20°C to +45°C. The use of the PROTEMP system not only increases operational safety and component lifespan but also sustainably reduces maintenance requirements.

Initial situation

On a ground-mounted photovoltaic plant, outdoor control cabinets equipped with a blue’Log park controller are to be operated reliably in an outdoor environment. Remote monitoring of the system is essential. The installed control, measurement, and regulation components are sensitive to temperature fluctuations.

In addition, batteries are integrated into the control cabinet to ensure power supply in the event of outages. For maximum battery lifespan, maintaining a stable temperature is essential.

Application conditions:

  • Ambient temperatures ranging from –20°C to +45°C
  • Direct sunlight exposure on the control cabinet
  • High levels of dust and moisture exposure
  • Sealed IP65 enclosure
  • Limited installation space for control cabinet climate management

Problem statement:
Without suitable enclosure temperature control, there is a risk of overheating in summer and condensation in winter. This can lead to system failures, measurement errors, and a reduced service life of the electronic components.

Challenge

A solution was required for efficient control cabinet climate management that meets the following requirements:

  • Reliable cooling and heating (heating & cooling in one system)
  • Low-maintenance operation
  • Maintaining the protection rating (IP65/IP67)
  • Compact design for limited installation space
  • Integration into existing monitoring systems
  • Remote monitoring of system status via the park controller.

Conventional compressor-based cooling systems were ruled out because they:

  • require more space
  • use refrigerants
  • cause higher maintenance requirements
  • are more mechanically susceptible due to moving parts

Solution approach: PROTEMP 70 M Outdoor

After evaluating various technologies, the decision was made in favor of the PROTEMP 70 M Outdoor Peltier temperature control system with a stainless steel enclosure – an energy-efficient solution for outdoor control cabinet climate management.

Why PROTEMP?

  • Combination of cooling and heating in a single device
  • IP67-rated – ideal for outdoor control cabinets
  • Compact design for easy integration
  • Maintenance-free and durable (no moving parts).
  • Energy-efficient operation through demand-based control
  • Status reporting for integration into remote monitoring systems
  • Corrosion-resistant stainless steel housing – also suitable for coastal regions

Installation is carried out directly on the side wall of the control cabinet. This allows excess heat to be effectively dissipated or heat to be supplied when temperatures are low.

The status output of the PROTEMP system is connected to a digital input of the blue’Log park controller. Via the meteocontrol VCOM monitoring platform, the operating status of the control cabinet climate system can be monitored remotely at any time. In the event of a fault, an automatic alarm notification is triggered.

Implementation in practice

After installation, the PROTEMP system is set to maintain a constant internal temperature between 5°C and 40°C.

Key advantages in this application:

  • Precise integration: even narrow side surfaces could be utilized
  • Temperature control: the system cools at high ambient temperatures and heats during frost conditions
  • Monitoring: integration into existing control and monitoring systems

Results after commissioning:

  • No condensation issues in winter
  • No overheating in summer
  • Stable and reliable operation of the electronics.
  • Significantly reduced maintenance requirements.
  • Energy consumption within the optimal range
  • Consistent performance even under extreme temperature fluctuations

Technical evaluation

From a technical perspective, the PROTEMP Peltier system is particularly convincing due to:

  • Precise temperature control within tight tolerances
  • Operation independent of installation position (even with angled mounting)
  • High operational reliability at temperatures from –20°C to +45°C.

The compact design also enables space-saving installation of multiple control cabinets side by side without any loss of performance.

Technical conclusion:
For outdoor control cabinets with medium heat dissipation, the PROTEMP system is a high-performance, energy-efficient, and low-maintenance alternative to conventional cooling units.

Customer benefits

The use of the PROTEMP Peltier system offers clear advantages for operators of photovoltaic systems:

  • Reliable control cabinet climate management protects electronics from overheating and condensation
  • Reduced maintenance requirements lower operating and service costs
  • A standards-compliant solution according to DIN EN 61439
  • Energy-efficient cooling through demand-based operation
  • High robustness and long service life under extreme conditions

The customer reports:
“Since the installation, the measurement cabinets have been operating stably and without interruption. The internal temperature remains constant, and we no longer experience failures caused by temperature fluctuations.”

Conclusion

The use of the PROTEMP 70 M Outdoor in ground-mounted photovoltaic systems clearly demonstrates:

  • Peltier-based control cabinet climate management is efficient, low-maintenance, and reliable
  • Reliable temperature control even under extreme environmental conditions
  • Compact, flexible, and standards-compliant integration
  • Extended service life of electronics and batteries through stable temperature conditions

For all applications involving outdoor control cabinets, the PROTEMP Peltier system offers a modern and high-performance alternative to conventional compressor-based cooling units.

Our technical experts are always available to support you competently in the planning, installation, and optimization of your control cabinet temperature management in photovoltaic power plants.

Guidelines for Proper Control Cabinet Thermal Management

The following steps have proven effective in practice for selecting a suitable PROTEMP system:

  1. Document or estimate power dissipation to realistically assess the amount of heat generated in the control cabinet.

  2. Determine control cabinet dimensions and enclosure material, as these influence heat dissipation.

  3. Check the operating conditions (indoor, outdoor cooling solutions, or offshore Peltier coolers) and define the maximum temperatures for both the environment and the interior of the control cabinet.

  4. Calculate the required cooling and heating capacity to determine the actual temperature control needs.

  5. Select the appropriate PROTEMP system that covers the calculated performance range.

  6. Check integration into the existing control cabinet, for example regarding installation space, power supply, and airflow.

    An overview of the various PROTEMP systems and their applications can be found on our product website.

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