Aesthetic solar panels

Overview

My Role: Mechanical engineering intern
Skills: Thin-film Application, CAD (SolidWorks), Machining
Timeline: June - August 2018 (3 months)
Team: N/A

Context

I joined Sistine Solar in June of 2018 through the Massachusetts Clean Energy Center Internship Program. I had always been interested in sustainability/ renewable energy and Sistine had a product that focused on the user side of the energy industry. Specifically, the goal was the increase adoption of solar panels in the US by improving the aesthetic appeal without significantly sacrificing performance. For this, they developed the Solar Skin, which could be applied to panels for any desired aesthetic.

When I joined, the Solar Skin would be applied to the panel in-house by the employees, before being sent out for testing or installation. The application process took around 10 minutes and at least two people. Because the sealing was done by hand manually, even a careful job could easily lead to air bubbles. In addition, water was necessary so that the skin could be readjusted (it didn’t stick until the water was removed) for alignment. However, this made the application process messy and also caused water waste.

Goal

Design an applicator such that a solar panel installer can apply the Solar Skin to the solar panel

• Bubble-free
• Quickly
• As an individual operation

Outcomes

The final prototype was an applicator that could allow a single person to apply the Solar Skin to the solar panel, bubble-free, in about 30 seconds, achieving the following improvements:

1) Application time 10 times shorter than the previous application method

2) Adjustable to different solar panel frame sizes

3) Does not require water for application, while still being accurate in alignment

A demo is in the video below:

Design Process

There was an initial rough model in place that utilized roller blade wheels, a cardboard tube, and spring hinges to form a machine that could roll along the panel to create even pressure for application. However, this was not successful because the solar panel glass had a slight curve to it.

The top priority for the applicator was that the Solar Skin was applied with even pressure to avoid any bubbles. Then, it was important that the process was faster than the current method and that it could be done by one person. Finally, a “nice-to-have” was the ability to adjust to different panel sizes.

With these design goals, I started ideation. Specifically, I researched cases that were similar to applying the Solar Skin and found that to be screen printing and lamination. Screen printing utilized large squeegees that would span the entirety of the sign in order to get a perfect application, while lamination was the same, but with rollers. While lamination required a static machine with a piece fed through, screen printing involved moving the tool over the piece. This was the desired method to keep the applicator size smaller.

I sketched several versions of a new applicator machine and discussed them with my supervisor. We decided to order materials that could be used to prototype multiple ideas with commonalities. I cut, machined, and assembled parts as needed and created the first prototype. Testing revealed several improvements that could be made and I updated the prototype to reflect these changes. Making this first prototype revealed insights that led to a substantially modified, but similar in concept, design for the second prototype. The sketching and material procurement process was repeated and finally, it was time to test.

Reflection

This was my first time applying design skills in the setting of a startup. One difficulty was the lack of access to the people who would be using the device, as they were the target customers to begin with. As such, only an initial prototype could be made to see if the functionality of the device was feasible, while other user-related considerations had to be left to future development. Overall, it was interesting and challenging to work with such a small team, as I had to work quite independently in both designing and building the prototype. However, this was rewarding in the end!