In this guide, I walk through the step-by-step process for assembling and installing basic solar road panels based on prototypes developed. My goal is to provide my experience based on my expertise in construction considerations, techniques, and components that contractors must address when undertaking solar road projects.
Step 1 – Design the Solar Panel Components
The solar panel itself forms the core component. Key design factors include:
Solar Cells – Select durable silicon cells 10-15% efficient. Higher is better but costs rise exponentially. Encapsulate cells between tempered glass layers.
Wiring – Embed wires linking cells with ample capacitance for collecting generated energy. Waterproof all connections.
Glass Surface – Textured tempered glass tops maximize traction. Ensure electrical insulation and impact resistance.
LED Lights – Incorporate LEDs for lighting and signage. Manage heat dissipation.
Sensors – Add sensors for vehicle detection if desired for interactive features.
Heating Elements – Install heating strips below the glass to potentially melt snow/ice. Insulate for efficiency.
Size and Shape – Standardize panel size for easier installation (12 ft hexagons or 4’x8′ rectangles).
Junction Box – Attach a junction box to each panel underside to connect the wiring. Make waterproof.
Step 2 – Evaluate Subgrade and Geotechnical Conditions
As with any pavement, solar roads require proper geotechnical and subgrade preparation:
Site Evaluation – Conduct borings and geotechnical studies to identify soils, bearing capacity, and drainage.
Moisture Mitigation – Install underdrains and stabilization materials as needed to prevent erosion and frost heave.
Grading – Shape subgrade to required grades and slopes for drainage. Remove unstable soils.
Compaction – Mechanically compact subgrade to 95% standard proctor density to minimize settlement.
Proof Rolling – Use heavy rollers to identify weak areas and remediate them as needed.
Aggregate Base – Install a dense-graded crushed stone base layer 8-12 inches thick. Compact in lifts.
Step 3 – Install Modular Support Structure
A critical step is constructing the base support system to which the solar panels attach. This includes:
Concrete Footings – Cast reinforced strip footings below the base layer to anchor the structure.
Sleepers – Secure treated wood or composite sleepers perpendicular to the roadway direction. These distribute loads.
Expansion Joints – Install expansion joint assemblies intermittently to accommodate thermal expansion and contraction.
Water Barrier – Add a waterproof barrier layer to prevent subgrade moisture damage.
Edge Restraints – Mount permanent edging/curbing around the perimeter to contain panels and base.
Wiring Conduits – Position conduits below sleepers to run wiring through. Seal connections.
Step 4 – Interconnect Solar Panels
The most technically involved step is mounting panels and connecting all electrical components:
Module Installation – Carefully place each solar panel module on the sleeper system. Leave room for expansion.
Waterproofing – Seal all panel joints with waterproof adhesive strips or silicone caulk.
Power Wiring – Connect each panel’s junction box to conduits using watertight, UV-resistant cables.
Ground Wiring – Bond each panel to create an equipotential grid for safety.
Monitoring – Link panels to control systems to remotely monitor power output and faults.
Lighting Integration – Connect LED lighting wires to activate safely based on conditions.
Sensor Integration – Complete sensor wiring for interactive features like vehicle detection.
Inspection – Thoroughly inspect the wiring, bonds, seals, and connections for issues. Remediate any deficiencies.
Step 5 – Test and Commission System
Before opening for traffic, extensive system verification is mandatory:
Standalone Tests – Power up each panel separately and validate proper functioning in daylight. Fix any errors.
Integrated Tests – Power the entire system and calibrate/adjust lighting and controls for smooth operation.
Safety Validation – Simulate traffic and weather conditions to confirm adequate friction, drainage, and hazard protections.
Monitoring Setup – Program monitoring systems and remote connectivity. Continuously scan for problems.
Trial Run – Prototype traffic including heavier vehicles and higher speeds. Rectify issues.
Documentation – Compile all inspection records, test results, certifications, and as-builts for ownership.
Training – Educate maintenance crews on repair procedures, electrical hazards, monitoring, and winter maintenance considerations.
