Case Study: Sun Tracker Project

Incorporated in 1994, Clairex Semiconductor is an internationally-recognized leader in semiconductor packaging that specializes in the design and manufacture of precision optoelectronic products used across a wide range of industries, including the aerospace, motion control, medical, encoding, transportation, commercial, and consumer electronics sectors.

Based in Plano, Texas, Clairex Semiconductor manufactures hybrid components, arrays, infrared and visible LEDs, photo-IC design, emitter-detector assemblies, custom optics, and custom assemblies. We are known for our capability to design and manufacture custom components that strictly adhere to customer specifications.

A customer in the renewable energy sector was referred to us after seeking a solution through one of our distributors in the US. This client needed a custom device that could track the movement of the sun with an accuracy of ±0.1° from horizon to horizon, giving an error signal at intervals that could not exceed 24 seconds. The customer could not find anything on the market that could meet their unique needs and as a mainstay in the solar power plant industry and the device they needed was key to large-scale solar power generation.

Creating the Custom Sensor

After the distributor gave Clairex the customer’s contact information, our engineering team met with the customer to get more details about the customer’s requirements. It was agreed that Clairex would develop a functional design, then build a working prototype.

Given the tight schedule, our team of electrical engineers immediately started working on the sensor design. Calculations and design specifications for the prototype were made over a two-week period, then verified by a prototype tested at the front entrance to Clairex on a sunny day.

In a parabolic trough solar power setup, solar rays heat fluid in a pipe, and that heat energy is used to generate electricity. However, for that to occur, the sun’s rays must be reflected onto the pipe with a low rate of error to ensure maximum contact and heating during the hours that the sun is available.

The custom sensor needed to align the solar equipment to reflect the sun’s rays onto a pipe that was 70 millimeters in diameter and about seven meters away from the parabolic reflector. Due to the distance between those two points, the apparent movement of the sun would miss the intended target without real-time and frequent correction. The purpose of the new custom sensor was to align the reflected energy with the target and enable automatic adjustments based on the apparent movement of the sun.

The sensor would also be out in the elements amid freezing temperatures, rain, sleet, and snow, and needed to withstand a wash down several times a week. The design required a NEMA-4 enclosure specified to guarantee safe and efficient operation in even the harshest weather and environmental conditions. Based on the customer’s specifications, Clairex designed an enclosure made from aluminum and an internal bracket made from machined aluminum. The sealed aluminum enclosure was itself designed to protect the sensor while still letting in the sun’s rays. The sensor was mounted in a TO-8 package with a silicon dual photodiode, had a window made from borosilicate glass with an aperture of ± 50 microinches in width—a very tight tolerance. It was mounted to a printed circuit board, enabling a network connection with the customer’s wider operation.

Several prototypes of the device were developed. We tested the design in our own laboratory using an LED to simulate the solar conditions on the actual site. The sensor was also subjected to a test fixture involving a standard infrared emitter. This custom test was able to verify the tight tolerances on the angle and showed that the component met the design goals.

The final design went above and beyond the original customer specifications, which required an error signal every 24 seconds. The sensor’s actual error signal rate of two-to-three seconds substantially exceeded the client’s expectations and enabling highly accurate adjustments of the solar equipment.

The custom solution was a success and resulted in a shared US Patent.

Learn More

Prior to this project, Clairex already had extensive experience involving a wide range of custom-designed optoelectronic components. However, this project was different from the normal projects our engineering teams handle. It required us to develop an understanding of basic celestial mechanics in a short time period, which was outside the realm of our electrical engineering experience. Additionally, the level of precision and tight tolerances required by the design made this prototype especially challenging to fabricate.

Clairex Semiconductor’s engineering team develops custom solutions with the tightest tolerances under the strictest timetables. To learn more about Clairex Semiconductor’s custom design and fabrication capabilities, contact us today.