Esteban IV: Taking solar propulsion to the next level

Each September, Montreal, Quebec closes Ste-Catherine street, one of the busiest streets in the city, to hold the “a day without my car” event. As the name implies, no motorized circulation is allowed on the street during this day, and a bunch of vendors present green-transport alternatives to cars.

This year, “L’école Polytechnique de Montréal,” a branch of “L’Université de Montréal” related to engineering, was presenting their solar car, named Esteban IV.

The Esteban Project was inaugurated in 1998 when a bunch of engineering students decided to design and build up a solar car prototype to participate in the 2001 edition of the American Solar Challenge. Unfortunately, due to electrical failures, the Esteban team did not qualify to make it to the start up line.

Now, ten years later, the vehicle is on its fourth revision, and is much more effective than the initial version.

Weighing 300 kg (661 lbs) and covered with eight square meters (~86 Sq. Feet) of monocrystalline solar cells, Esteban IV is powered by a 5000-watt lithium-ion polymer battery. Its external shell is made from Kevlar, carbon and glass fibers, and its tubular structure from aluminum.

Currently, the vehicle can reach a top speed of 110 km (68 mph) per hour, but according to what I was told by the spokesperson that was there, the ideal cruise speed should be around 65 to 70 km (40 to 43.5mph) per hour. At that speed, on days where the sun is shining bright, the car could go on indefinitely, consuming all the energy it produces, no more, no less. On cloudy days, the car, running partly on solar and battery power, can be propelled for around four consecutive hours.

The Esteban team is looking to improve their vehicle further by replacing various parts to lighten up its load, namely the steering wheel and steering wheel’s shaft, which are currently made from steel.