Skip to main content
Success Story | 2 minute read

Kollmorgen’s low-temperature servo technology simplifies cleaning of solar energy heliostats

Since the turn of the 21st century, China has aggressively pursued solar technology and is today the world leader in both photovoltaic and thermal solar energy.

Thermal systems rely on a large array of heliostats—mirrors that automatically move throughout the day to reflect sunlight to a central point, where the intense heat drives a power-generating turbine. Similarly, heliostat concentrator photovoltaic or HCPV systems use heliostats to focus sunlight on solar cells, which convert the light energy directly to electricity.

The development of these technologies—along with China’s rapidly growing capacity to manufacture them—has opened many new opportunities for sustainable energy production in international markets. At the same time, the demand for efficient energy production creates a new market need to optimize heliostat performance.


Heliostats need to be cleaned regularly for the system to deliver maximum efficiency, but this is not an easy task. First, there are environmental conditions that must be addressed, including operation at high elevations and oftentimes at temperatures as low as –30°C. Additionally, airborne dust, which can be either acidic or alkaline, clings to the heliostats and causes weakened light intensity on the mirror planes, lowers the reflectivity of sunlight, and reduces power generation efficiency.

Heliostats must be routinely cleaned to remove this dust—a task which is complicated by the need to dynamically adjust the angle of brush rollers as the mirror surfaces continually track the angle of available sunlight. The variable properties of the dust, heliostat position and environmental temperature all contribute to the complexity of the cleaning challenge.

Kollmorgen’s Low-Temperature Servo Technology Solution

A common heliostat cleaner on the market consists of an electric car, a gantry crane arm and an inclined brush roller. However, the difficult geography where these are used often requires manual intervention by the driver, and system failures are frequent when common asynchronous motors can’t withstand the harsh conditions.

A new cleaning vehicle design was needed to solve these challenging problems. This new design uses servo technology featuring Kollmorgen’s AKM low-temperature servo motors and AKD servo drives. The vehicle incorporates a gantry straddle structure with an auto-drive system that is positioned using GPS technology. The AKD servo drive, with its high-precision motion control capability, enables the gantry to move in a synchronous manner to accurately and automatically adjust the tilt angle of the brush roller.

High-performance AKM servo motors are used to power the movement of the cleaning vehicle. A steering system that controls the wheels through four sets of AKM motors and AKD drives provides excellent motion control for flexible and responsive steering over unpredictable terrain. And the AKM low-temperature servo motors allow for reliable operation even in extremely cold environments, as low as –40°C.


Improving the performance of its cleaning vehicles was the number-one priority for this customer. Kollmorgen’s AKM low-temperature servo motors deliver predictably steady performance in challenging high-elevation, extremely cold environments. AKD servo drives provide industry-leading current, velocity and position loop update rate, optimizing performance in fractions of a millisecond while greatly improving the device’s efficiency.

Targeted product design and easy-to-use debugging software greatly shortened the project development period, helping to bring the new cleaning vehicle to market quickly in a rapidly progressing industry.

In a typical solar energy facility, 10 people per day were previously dedicated to cleaning heliostats, with two minutes required to wash each mirror. Today, these requirements have been reduced to only two people per day and only 10 seconds per mirror. The Kollmorgen solution has perfectly solved the customer’s requirements for improved environmental performance and control, achieving higher market competitiveness and greater market value.

About Kollmorgen

Kollmorgen has more than 100 years of motion experience, proven in the industry’s highest performing, most reliable motors, drives, linear actuators, gearheads, AGV control solutions and automation platforms. We deliver breakthrough solutions that are unmatched in performance, reliability and ease of use, giving machine builders an irrefutable marketplace advantage.

Contact Us

Direct Drive Motors Improve Flexographic Printing Performance

Recent work done by Kollmorgen—a global leader in manufacturing motor and motion solutions—has shown that it is possible to synchronize components within the flexo printing process without mechanical transmission by using closed loop control technology. This synchronization is key to managing web tension throughout the process while ensuring a steady repeat length.

Learn More

Stepper Motor or Servo Motor: Which Should it be?

This article presents an overview comparison of stepper motor and servo motor capabilities to serve as selection criteria between the two technologies.

Learn More

Engineer the Exceptional

Learn how to engineer exceptional machines, robots and vehicles with the highest-performing, most reliable motors, drives, automation solutions and more.

Learn More

Related Resources

Accelerating the Development of Next-Generation Prostheses and Exoskeletons >

Learn how Kollmorgen servo technology is helping OEMs accelerate the design of next-generation prostheses and exoskeletons.

Kollmorgen and Stereotaxis Advance the Precision and Safety of Surgical Robots >

Kollmorgen’s advanced motion products and expertise are helping save and improve lives. Learn how the new Genesis surgical robot incorporates torque-dense AKM servo motors with specialized, integrated encoders to revolutionize cardiac ablation…
Kollmorgen Express Delivery significantly shortens lead times for the company’s most popular motion products

Kollmorgen Express Delivery significantly shortens lead times for the company’s most popular motion products >

Motion leader Kollmorgen announces a new classification for select products that can be delivered within an accelerated timeframe.

Stop, hold and go safely: Motion tuning for vertical loads >

When designing motion for applications such as vertical gantries and hoists, you need to take special care to ensure operator safety and operational efficiency. Let’s discuss best practices for meeting the particular challenges involved.

What are the Five Major Components of a Brushless Servo Motor >

Servo motors are used in numerous markets to power machines, instruments, robots, and other factory automation applications. This blog addresses five major elements of a conventional brushless DC servo motor: the rotor, stator, bearings, feedback and…
What is a closed-loop system?

What is a Closed-Loop System? >

When learning about servo motors and servo systems, you’re likely to encounter the phrase “closed-loop system.” If you’ve ever wondered what that means and how it works, you’ve come to the right place. Let’s step through some of the most common…
Printing Machine

Direct Drive Motors Improve Flexographic Printing Performance >

Recent work done by Kollmorgen—a global leader in manufacturing motor and motion solutions—has shown that it is possible to synchronize components within the flexo printing process without mechanical transmission by using closed loop control…

How to Customize a Servo Motor - Standard vs Custom >

When and how to customize a standard servo motor depends on the predicted benefits derived from the customization that should include a solution tied to form, fit, and function. Learn more.
Kollmorgen webinar, What is a Servo Motor?

What is a Servo Motor? >

When researching motor options for an application, one type that often comes up is “servo” motor. Many manufacturers expand and add descriptions like AC and brushless. What do these terms mean and what exactly is a servo motor?