That morning, we ride a bike like no other. The black frame is reduced to a wide band connecting the two wheels. A first pedal stroke, a second, and off you go! In Montrouge (Hauts-de-Seine), we are on the saddle on what could be the bicycle of tomorrow.
Called Sun-E, this Rool’in company prototype is one of the first solar electric bikes in the world. Despite its 25 kilos, a weight comparable to that of conventional electric models, its ride is particularly smooth.
Solar e-bike on sale in 2020?
The model will be tested for the first time in a few weeks, in the towns of Montrouge and Issy-les-Moulineaux, by municipal staff and French La Poste. This first step will make it possible to adapt the model according to the feedback of the first users before going for commercialization, by 2020, at the initial price of 5 700 euros.
“We have been working on the motorization of traditional bicycles for several years,” says Antoine d’Acremont, co-founder of Rool’in, a company created in 2013. “A question always came back to our riders, how can we not be blocked by the stress of recharging the battery and have a better autonomy?” He explains.
In 2017, he and his team decided to develop a bike whose frame and front wheel would integrate photovoltaic panels capable of supplying electricity to the engine.
First models of solar bicycles had already been invented, but they were equipped with such wide panels, often placed at the level of the luggage rack, that their circulation in the urban environment was almost impossible.
The challenge for Rool’in was to build an e-bike frame that is practical, lightweight, energy efficient, but also strong enough to withstand the jolts of journeys.
From 18 to 26 kilometers of autonomy in the city
For this, “we have produced custom panels, which are thin layers of polymers in which are encapsulated solar cells. These panels stick to the frame of the bike and the spokes of the wheels. Everything is weather and scratch resistant,” says Antoine d’Acremont.
Another precious feature of these cells is their differentiated functioning. If one cell happens to be in the shade, while the neighboring cell is still in the sun, it still produces energy, unlike the panels installed on the roof, for example. In total, these
The battery and the mains connection allow, if necessary, to bring in additional energy, while the screen indicates the level of charge in real time. The company announces a ten-year lifespan for its e-bike.
The Montrouge start-up is not alone in the niche. Last January, Nokia, the Finnish telecom giant, presented its concept at the CES, the world electronics fair, in Las Vegas (USA).
With three wheels, one at the rear and two at the front, two seats next to each other and the roof, to which photovoltaic panels have been integrated, the Solar Connected Bike is much wider and imposing than Sun-E. “Our goal is to make our vehicle as autonomous as possible,” says Patrick Noël, Nokia’s original bicycle engineer.
A rally of clean bicycles
The current solar e-bike is a concept model and is not intended to be marketed at the moment. “For this project, we were inspired by the Solar Impulse aircraft,” says Patrick Noël. Between 2015 and 2016, this 100% photovoltaic aircraft, created by the Swiss Bertrand Piccard and André Borschberg, had managed to go around the world.
Still in its infancy, the solar electric bike is already in its first serious run, the Sun Trip, a rally organized every two years since 2013, which connects distant destinations, such as Lyon and Canton (12,000 kilometers), in 2018. Both wheels of the participating bike must be electric and the solar panels, usually attached to the roof or the trailer, must not exceed 5 square meters.
The goal of this rally is to achieve total autonomy during the journey (without recharging the battery via an electrical outlet). “I am absolutely convinced that the solar bike will be, in five to ten years, at the stage that will follow that of the electric bike”, predicts Florian Bailly, the organizer of the rally. To make this happen, the pricing of a solar e-bike needs to go down.
And what about solar roads?
Cycling routes are a dream medium for photovoltaic energy producers. The Dutch company SolaRoad, a pioneer in the sector, has understood this and has already equipped portions of road the not only in the Netherlands, (since 2014), but also in France, in Etampes (Essonne) since 2017, and Montoir-de-Bretagne (Loire-Atlantique) since 2018.
These channels recover solar energy and reinject it directly into the grid, for example, for street lighting. “We are able to produce 90 kWh per square meter per year, which is the consumption of three homes of 100 square meters”, proudly announces Sten de Wit, co-founder of SolaRoad. “Our next step is to build solar roads for cars, which can recharge the vehicles simply by being rolled over,” he says.
This post was translated from French. The original version was published on Le Parisien. Photo credit – Le Parisien.