Designed a robotic system to scale building façades and install solar panels without scaffolding. Developed full CAD assembly, prototyped key subsystems, and validated load-bearing safety through FEA and testing.
WallE is a solar panel installing robot we built to rethink how cities adopt renewable energy, especially in dense urban environments like New York City where rooftop space is limited. Instead of sprawling solar farms, our idea was simple and backed by research: go vertical. Our goal was to unlock untapped vertical real estate by making solar retrofits safer and more feasible.
The Problem
• The price of photovoltaics has dropped 80% in the last 10 years, but installation prices in the United States have remained high.
• Rooftop solar space is limited in cities like New York, where real estate is scarce.
• Installing panels on facades requires scaffolding that is dangerous, costly, and labor-intensive.
→ Goal: Enable cities & individuals to retrofit existing buildings with clean energy by reducing risk for workers and unlocking untapped vertical real estate.
The Concept
Needed a robotic system that could:
• Securely clamp to buildings.
• Carry and align solar panels.
• Is modular, safe, and manufacturable.
Explored three main approaches:
• Vacuum suction: unreliable on porous brick surfaces.
• Magnetic adhesion: limited use on masonry.
• Clamp + winch system (final): reliable on brick, safe, manufacturable.
→ Selected clamp + winch design for reliable load transfer and scalability.
CAD render of early concept
The Design & Engineering
Subsystems Breakdown:
Chassis + Wheels
Universal Clamp
Winch (housed in clamp)
Solar Panel Frame
Streamlined installation process:
Clamp with attached winch is installed
First panel clicks into place
WallE begins installation
Arms snap panel into connectors
Extension arms retract
Repeat
Designed chassis + roof clamp with manufacturability in mind (sheet metal brackets, injection-moldable clamps).
Integrated winch, clamp arms, actuators, and electromagnets.
Ran tolerance stack-ups for bolt–bracket fits.
Conducted FEA on suspension brackets → validated 25 kg load with safety factor 1.5
Led design and fabrication of the chassis and roof clamp.
Integrated subsystems: winch, clamps, actuation arms, and electromagnets.
Applied tolerance stack-up analysis for clamp bracket and bolt fits.
Ran FEA on clamp arms and suspension brackets → validated 25 kg load with safety factor 1.5.
Added ribs and fillets to reduce stress concentrations.
The Prototyping
Fabricated initial clamps in PLA → fractured at 20 kg load.
Switched to PETG with thicker cross-sections (+2 mm wall) → passed testing.
Built full-scale prototype for vertical wall testing.
Prototyping & Iteration
Clamp v1 (PLA): fractured under 20 kg → redesigned in PETG, +2 mm wall thickness.
Panel placement: electromagnets misaligned → added actuator arms.
Winch durability: motor overheated → added heat sink.
The Tests
Under a 45 lbf vertical load, the most critical clamp feature is ~2.6× below yield → elastic, no permanent deformation expected
We devised a test scenario where the clamp is holding fifteen modules and instead of being placed the robot is dropped causing a sudden increase in load. We performed FEA analysis on the load bearing parts of the clamp and found that its bearing capacity was higher than necessary for our project. As a result, we plan on making the clamp smaller to maximize material efficiency.
changed the pins
Testing & Validation
Clamp tests: Supported 25 kg with <1 mm slip.
Climbing test: Scaled 2.5 m brick wall.
Panel installation: Snap-fit + magnet system aligned panels securely.
Testing & Failures
Clamp Load Test: Initial slip under 20 kg → redesigned teeth geometry for better grip.
Electromagnet Panel Handling: Failed to align panels consistently → added linear actuator for precise placement.
Winch Durability: Motor overheated after 5 minutes → added aluminum heat sink.
The project featured several novel components, including a custom designed modular solar panel frame and a magnetically interlocking system that allowed for seamless mechanical and electrical connections between stacked panels. These modules were designed from scratch to simplify installation and maximize alignment and surface adhesion.
Our robot clamps to a building’s parapet and descends down the wall using a winch system. It carries modular solar panels and installs them directly onto the facade using a combination of linear actuators and magnetic alignment. Each panel snaps into the one above it, creating a secure mechanical and electrical connection as the robot moves downward.
I worked alongside five teammates over the course of a year. My contributions were concentrated on testing & prototyping, mechanical integration, and finite element analysis (FEA) of key load-bearing components. I led the design and fabrication of the robot’s chassis, and integrated and tested all the key subsystems (winch, clamp and actuation mechanism). I also conducted FEA on our roof clamp and suspension brackets to validate structural safety under expected loading conditions.
Key features of the system included:
• A motorized winch and cable system for vertical movement
• A roof parapet clamp engineered for reliable load transfer
• Extension arms with linear actuators to mount solar modules
• Electromagnets for precise panel handling
• A scalable and fully functional prototype that climbs and installs solar panels on a vertical brick test wall
WallE installing a solar panel
Close up of our frame and locking mechanism
We validated our design through mechanical testing and simulation, including motion studies, peel adhesion trials and FEA. Our work was presented to faculty and peers, and the final prototype demonstrated the feasibility of a robotic solar retrofit system for urban buildings.
Final testing before showcase!
WallE is more than a robot, it’s a concept for bringing scalable solar infrastructure to New York City. With more time and resources, we see this becoming a real world system capable of reducing labor risk, speeding up solar adoption and making green energy a default in cities like New York.
