Electric bikes are great for making short journeys a touch more effortless and one upcoming electric bike may never even need to be plugged in to charge. The Leaos Solar e-bike has solar panels built into its frame, which the manufacturer says can make it energy independent at certain usage levels.
The Solar e-bike bike uses an auto pedal-assist system, but will also have an electric drive setting. According to Leaos, the bike can be self-sufficient for what the company calls "medium usage" of up to 20 km (12 miles) per day in pedal-assist mode or about 16 km (10 miles) in pure electric drive mode. At that level of use, Leaos founder Armin Oberhollenzer tells Gizmag that the battery will never entirely run down because its solar panels will charge the battery continuously, so long as there is light available.
The Leaos Solar e-bike was designed alongside two non-solar sibling models, the Leaos Pure and the Leaos White. Oberhollenzer says their unusual shared form was aimed at being both stylish and able to contain the various technical components of an e-bike.
It features a carbon fiber monocoque body, carbon fiber handlebars and a carbon fiber mudguard. The solar paneling is integrated into the body itself and, according to Oberhollenzer, comprises "ultrathin panels that will go close to 20 percent [conversion efficiency] and that are not on the market yet."
According to Oberhollenzer, although the PV panels do work better in bright sunlight than ambient light, the difference is not that dramatic. He says that a variety of other factors, including the angle at which sunlight hits the panels, can reduce the effectiveness by 70 percent.
With this in mind, prototypes of the bike have been tested extensively in both Italy and in the cloudier climate of Germany. Oberhollenzer is confident that the "20 km per day" self- sufficiency figure is accurate and says it reflects real, varied usage.
The total area of solar panel coverage is still to be finalized. Oberhollenzer notes that as much of the bike as possible could have been covered in panels, but that aesthetics had to be taken into account. It is for this reason that the panels are side-mounted. Integrating the solar panels, says Oberhollenzer, has been the most challenging aspect of the design.
Also unknown at present is exactly how long a full charge on PV alone will take, though Oberhollenzer reckons that it will require in excess of 24 hours of sunlight. The 36 V battery can be juiced up to capacity in around two hours when connected to a mains supply though, which should then give the e-bike a range of 90 km (56 miles) in pedal-assist mode or 72 km (45 miles) in electric drive mode.
"Obviously a solar panel will never charge as a speed charger," says Oberhollenzer. "But that is not the objective. The objective is to be independent from traditional power supplies for 'normal' usage."
An Indiegogo crowdfunding campaign for the Leaos Solar e-bike was run last year, but backers barely made a dent in the targeted US$190,000 and the campaign closed unfunded. Oberhollenzer tells Gizmag that the project has since been financed privately, however, and that the e-bikes will be available globally from July/August 2015. They can be pre-ordered now with prices starting from from €7,900 ($8,960) depending on configuration.