Charge anywhere.
Built for hail, rain, and high-winds. Compact, when you drive it. Expands, when you park it. Gain 20 to 40 miles per day. Payback period 2-to-3 years.
Manual or automatic?
Expand or contract it manually in under a minute, or install an actuator to do it automatically. All actuator software for Arduino and Raspberry Pi will be made available.
Repairable.
If a part breaks, you can 3D print it, or go to your local hardware store and cut the metal you need. Blueprints and 3D models for repairs will always be available.
Theft-proof.
Once attached only you can remove the Beta2 from the roof rack. It can attach to any roof, rack, or mount.
Hey good looking.
At five-inches in height, and 1575 watts of power the Beta2 will be fun to build and to use for off-grid charging. Dimension: 35 inches wide, 64 inches long.
Details
Solar panels
For this build, we are using 175 W Renogy flexible solar panels that are each 3 mm thick and weigh 7 pounds. The solar panels are fantastic because we can minimize the height profile of the Beta2. We had to alter these solar panels such that the junction boxes are in the rear of the panel, half inch from the edge. In total Beta2 has 1575 W of solar panels. We prefer smaller solar panels working together due to rocks or hail, it's simpler and less expensive to replace a smaller panel than a larger one.
Electrical components
The DC power sourcing from the solar panels enters the trunk of the car via a cable that passes through the trunk door rubber gasket. This feeds into a power unit, currently we’re using a DeltaPro but you can also use the EG4 3kW Integer + ECO-WORTHY 48V 50Ah battery. The power unit converts the solar DC power to AC, which connects to the universal charger adapter. We hope that in the future, Beta3 will be able to charge the car directly with DC power.
Telescopic tubes
For this build we used carbon fiber telescopic tubes that were sourced from fishing poles. These telescopic tubes do not lock fit, in the sense that they can overextend and never contract. The specific fishing pole we purchased can be ordered from Temu.
For Beta3, we started designing our own telescopic tubes. We will release the blueprints for the Beta3 telescopic tubes soon. That way you can use aluminum or steel-made telescopic tubes — to add extra rigidity and durability to your solar array.
Metal frame
Beta2 is built using 6361 aluminum alloy square tubes that are 1" x 1". The base of the frame is composed of square aluminum tubes that are 1 inch and 1/4. Aluminum tubes are connected with brackets, rivets, and 3D printed parts. The metal frame connects to an existing Tesla roof rack, which we are looking to replace with the Beta3.
The Beta2 frame is theft proof because one can use secured nuts and bolts. The solar panels have their junction boxes in the frame itself and are glued with silicone — these will be rendered useless if they are removed by force.
Aerodynamic drag loss
Beta1 was 13-inches in height and it was aerodynamically inefficient. Beta2 is only 5-inches in height and reduces the efficiency of the Tesla Model Y by 10%. In our tests we did not use any wind or tail breakers. The Beta2 with its flat front face was used for the tests. Beta2’s aerodynamic drag loss can be decreased if one adds a windbreaker.
Beta3 will be only 1-inch in height and will directly connect to the rooftop of the Tesla Model Y. As such, the aerodynamic drag loss of the Beta3 will be negligible, we estimate it at 1%. So driving 200 miles, only 2 miles worth of rage will be lost due to the aerodynamic drag loss of Beta3.
Charging
Charing a Tesla Model Y in Los Angeles, CA in February 2024, using the 1575 W Renogy solar panels and the DeltaPro as the power unit, allowed us to gain 25 miles per day on average. The range was between 20 miles and 30 miles. All the solar panels were flat directly pointing to the sun.