“The car has three major parts: the mechanical system, the electrical system, and the shell,” Prof Rene Fernandez, Team Sinag’s overall technical team leader, explains. “All of these elements work together to keep the car going.”

Steering made simple. Nothing could be more straightforward than SINAG’s mechanical system. Avoiding the common steel chassis and “double wishbone” front wheel suspension system used on conventional cars, it favors an ultra-light monocoque frame with three wheels – one heavy-duty rear wheel to drive the car forward, and two front wheels to steer. Amazingly, in yet another nod to Filipino ingenuity, SINAG’s steering system consists of surplus motorbike front forks and wheels – the same kind found on public utility tricycles.

Inside, the driver sits at a comfortable reclining angle of 27 degrees and is safely protected by a rollbar cage. The instrumentation is just as uncomplicated, with gauges for pedal pressure, speed, and battery power, plus a cruise controller on its uncluttered dashboard.

A power balancing act. On top of SINAG’s shell is the most distinctive part of the car and the most visible part of its electrical system: the 400 solar cells that generate a combined output of as much as 2kW. Proudly Philippine-made, these industry-leading model A-300 solar cells from SunPower boast the highest efficiency of any commercially available solar cell in the world. The monocrystalline silicon structure of SunPower’s cells and their exclusive back-contact technology give them a distinctively smooth black surface, which helps them convert more of the sun’s energy into electrical energy than conventional cells do. Each cell has an efficiency of as much as 21%, whereas other commercial cells are rated from 15% to 17% at most.

The solar cells, connected in series to form a large solar array, are hooked up to the car’s electrical system and power the rear-wheel motor to propel the car forward at speeds of up to 100km/h. The car’s electrical system also includes Kokam Lithium Polymer batteries that store excess power generated by the solar cells, which could later be tapped by the motor when there is a sudden reduction in the amount of energy received from the sun – as in the case of a transient thick cloud cover. The 120v batteries can be charged to full capacity in five hours and can continuously power the car running at top speed for 4 straight hours.

This whole power balancing act is orchestrated b SINAG’s electrical system, which regularly monitors its power requirements and keeps track of how much solar power is being collected, how much power is stored in the onboard battery, how fast the driver wants to go, and other variables. There’s even a telemetry system that constantly sends data on the car’s health via radio to two support vehicles that will travel alongside SINAG.

It’s all in the shell. The shell of hull, even though it has no moving parts, was actually the most difficult aspect of the car to design and build. Getting the right shape was crucial for the SINAG team because it would greatly affect the performance of the whole car: too small and there might not be enough space to put in the solar cells to power it; too big and it would be sluggish and waste too much energy as it moved forward. Having a curve in the wrong place creates a dragging effect when the car moves forward at high speeds, thereby slowing it down.

“We did a lot of research and used computer models to determine the right shape. We came up with one that’s very aerodynamic, with a 0.1 drag coefficient,” said Fernandez. “The smaller the drag coefficient, the less energy would be needed to move the car forward. In contrast, and average car on the road has a drag coefficient of 0.3.”

The hull is made of pre-scored Termanto PVC boards covered with carbon fiber weave, which would make the car strong yet as light and flexible as possible, helping to further reduce its power needs.

Racing the sun. Designed and constructed from Philippine-made materials by a passionate all-Filipino team, SINAG is slid proof of how far a nation can go to achieve a promising and clean future.

For months, mechanical engineering and electronic & communications engineering students from De La Salle University – Manila laboriously designed and constructed this revolutionary vehicle, determined to complete the World Solar Challenge in Australia, and prove to the world that the Filipino can stand shoulder with other progressive nations in developing solar power as an environmentally-safe, alternative energy source.