At first glance the Sunnyclist looks like a typical electric tricycle, yet the combination of a solar panel on the roof with pedals for the passengers ensures that its battery can go a long way without requiring an external power supply.

The Sunnyclist was born in 2011 when a group of young engineers and entrepreneurs from Greece came up with the concept. By 2012 they had the first working prototype and in 2013 a second prototype was being tested. Some remarkable feats have been achieved in the process, like a tour of the island of Crete that involved covering 800 km (497 mi) in five days. It has also been tested on a hillclimb from sea level to an elevation of 1.1 km (0.68 mi) through both paved and dirt roads.

The tricycle is built around a sturdy and lightweight aluminum frame, measuring approximately the size of a small city car. Its power source is a lithium iron phosphate (LiFePO4) battery, feeding two 6 kW brushless motors contained within the rear wheel hubs.

So far things are pretty conventional, but there are also some alternative means of charging at hand. The Sunnyclist's roof is essentially a big, rotatable photovoltaic panel that can track the position of the sun in order to improve its overall efficiency by as much as 30 percent.

Finally, there's a third potential charging force at play in the form of a Pedal Power Pack. A Shimano crankset with SPD pedals at the driver's feet can provide an alternate charging device, while two more detachable pedal packs are available for use by the two passengers sitting in the back seat. Pedaling does not produce any direct propulsion as there is no transmission system installed on the Sunnyclist. Instead, muscler power is employed solely for charging the battery, regardless whether the vehicle is moving or not.

The Sunnyclist's technology in a nutshell Sunnyclist

Cleverly enough, the detachable Pedal Power Pack can be also used at home with a specifically developed bike frame to produce electrical power while exercising. There's also the option to order the Pedal Power Pack Pro, which includes adjustable pedal resistance.

According to the Sunnyclist's designers it has been tested to a maximum distance of 70 km (43.5 mi) at an average speed of 35 km/h (21.7 mph) relying only on its battery. Add to this another 70 km from its solar generator (on a sunny day) and top it off with 50 km (31 mi) more from the pedals and you get a maximum range of 190 km (118 mi). Using an even bigger battery pack, should improve its range considerably. When the battery is fully charged, a controller diverts the power generated from the solar panel and the pedals straight to the electric motors, extending the battery's range.

Relying only on pedal power and the possible assistance of solar charging, the designers say the trike can still produce enough power for a 20 km/h (12.4 mph) speed on a level surface – so it could be moved to a nearby charging point or a sunnier spot. A full battery charge by only sunlight is also possible, requiring approximately a day's worth of exposure to the sun.

The pedal power pack has been designed to provide extra juice for the Sunnyclist - and can double as a static exercise bicycle at home Sunnyclist

The Sunnyclist is classified in the European Union as a class L5e vehicle (solar-electric tricycle), with a top speed of 50 km/h (31 mph) and it will be produced in three variants. The City version is equipped with a 540 W photovoltaic generator and a 60 Ah/48 V battery that can provide an average of 35 km (21.7 mi) on a single charge – without taking into account solar or pedal power.

The Traveler version has a larger 680 W solar panel, is equipped with pedals for each passenger, an energy analyzer and a 100 Ah/48 V battery for the maximum range of 190 km with the synergy of all available power sources.

Finally, a Standard version is planned for use in large private facilities such as hotels. Powered by a 40 Ah/48 V battery it can provide a maximum range of 25 km (15.5 mi).

The Sunnyclist can be accessorized to enhance its ability with an extra two-passenger seat, extra cargo space and lots more Sunnyclist

The Sunnyclist is capable of transporting three passengers in its standard form and includes two 75 liter storage spaces in the front and space for larger objects behind the rear seat. By removing or folding this seat, the back of the vehicle can be used to haul cargo up to 250 kg (551 lb). An extra rear-facing seat can also be added to accommodate two more passengers.

The Sunnyclist has just launched an Indiegogo crowdfunding campaign in order to muster the finances required for production to begin in 2016. Find out more in the following campaign video.

Sunnyclist: The world's greenest vehicle

Source: Sunnyclist