Solar Velo

Solar Velo

De avontuurlijke weg naar vrijheid … zonder fossiele brandstoffen!                 31 August 2020

December 2019: One Planet gelooft dat een nieuwe Solar Velo alle huidige records van de Sun Trip zonnefietsrace naar China zou kunnen breken en zou graag een partner vinden die deze uitdaging aangaat. Dit doen we om moderne fossielvrije mobiliteit te promoten en een inspirerend en avontuurlijk voorbeeld te geven!

Albert Einstein was fond of making ‘thought experiments’ about how things worked; then later his predictions were proven by others in practical tests to be true. In the same vein, though much simpler, having translated into English Raf van Hulle’s book about the 2018 Sun Trip race, we at One Planet got the strong feeling that the current technology and machines used in this bi-annual solar assisted 12,000 km bicycle race from Europe to China, are still in their infancy. It is like comparing racing cars from the 1940’s with the high-tech Formula One machines of today. If you apply a ‘thought experiment’ to the Sun Trip, it seems inevitable that the rather ungainly solar bicycles used now, will in future become streamlined velomobiles covered with solar panels. This change will dramatically lower their wind resistance and increase speed, perhaps even doubling it?

If you want to win the Sun Trip race, then we think ‘the writing is on the wall.’ Instead of taking 44 days like Raf does (which is far ahead of his competitors) maybe you can do it sometime in a Solar Velo in under 30 days? Even more tantalising, machines like the Dutch Quattrovelo being built in Dronten, seem eminently suitable for conversion right now into solar-assisted designs. Our fingers are itching to prove this. At One Planet, we have the innovation but lack the funding and time to build one of these Solar Quattrovelo’s. (The first race machine would cost, including development, perhaps the same as a family car. Subsequent models would be much cheaper.) So, instead of sitting on ideas that we are unable to develop ourselves, let’s share them on internet and see if someone else can use them. Wouldn’t it be nice if someone out there did have the resources and used this idea to sweep to victory in the 2021 or 2023 Sun Trip challenge! Thereby showing that ‘the world is your oyster’ waiting to be explored in a fun, eco-friendly and sustainable way without ever using one drop of fossil fuel. Solar Velo’s could make touring motorcycles seem like smelly and polluting dinosaurs of the past. You can stay at home tending the geraniums … or jump into your Solar Velo and go have an adventure!


  • The average speed of a velomobile is much higher than a bicycle, because the air resistance is less. A speed of 40 km/hour requires 352 Watt with a bicycle, 265 Watt with a recumbent bike and only 157 Watt with a velomobile. That is half the energy requirement of a bicycle! The faster velomobiles give 60 km/hour on a flat road with 180 Watt. The effect of air resistance can be seen in the graph in Raf van Hulle’s book page 9. At 30-35 kg, a velomobile is slightly heavier on a long slope than a bicycle, but no heavier than a Sun Trip bicycle.


  • Recently Nicola Walde pedalled 1088 km in 24 hours on a velomobile. This was in a stadium, but even so, that is a big achievement for human-powered mobility. The record for a man is 1219 km. That is three times further than the record for a Sun Trip participant with an e-bike. With the addition of a solar-powered e-motor, a solar velomobile will become even faster!

  • Raf van Hulle says on page 18 of his book; technology and knowledge are now more important to the Sun Trip than muscle strength. Look at the Sun Trip bikes on page 19. They resemble race cars from the 1940’s. They are largely home-built amateur machines. Participants compete for fun and adventure more than winning. So, the Sun Trip is in the early stage of its history; where will it go in the future?

We think it will go to Solar Velo’s but how can you cover the curved surface of a velomobile in solar cells?

A)     With strips of thin-film solar cells, which can follow the curved shape of the vehicle body. The return on the cells is lower; 18% efficiency. There are algorithms to calculate the optimal covering.

B)     With rigid 23% efficient mono-crystalline cells that are individually glued or laminated to the body, with its own wiring per cell. If the 3D shape of the velomobile has been loaded into a computer, the optimal placement of the cells can be calculated. A robot can position the cells individually and drill holes for the wiring. Tubercles on the skin can reduce air resistance in certain situations

In addition to the cells on the body (giving 1 to 1.3 m2?), a 1.32 m2 solar panel can also be mounted above the velomobile; see concept drawings below. This offers space for at least 5 x 15 = 75 cells of 125 mm = approximately 262-Watt peak. In this way the Solar Velo can generate 200-400-Watt peak; or more than enough for 40-60 km/hour. With muscle power added to solar power, the Solar Velo becomes by far a Sun Trip winner!


Solar Quattrovelo+

As a design starting point, take the factory standard Quattrovelo+ body as a basis, and replace the standard hood with a self-built hood into which a streamlined solar panel has been integrated. This hood can tilt up to allow the rider to climb in and out in the normal way.  In addition, the body of the Quattrovelo is covered in solar cells, like the scales on a fish. The ‘tail’ can fold forwards for easier parking. 

One Planet would be happy to partner with someone to make a detailed:

  • Project proposal
  • Budget and financing plan
  • List of technology partners
  • Promotion plan

Why use the Quattrovelo as a basis for the new Solar Velo?

  • It is the only standard four-wheel velomobile, making it more stable and safer than the traditional “tadpole” tricycle. This makes it much easier to carry a solar panel.

  • Traction on two rear wheels is better. And since all wheels have the same 20” size; you only need to bring 1 spare tire on a long journey or race like the Sun Trip.
  • With four wheels one can ride over the white line on the shoulder of the road. The traditional three-wheeled velomobiles drive with the rear wheel on the white line; this can be dangerous and has led to near-accidents.

  • The luggage compartment of the Quattrovelo is much larger than other velomobiles; it even has room for a child in the back. The Sun Tripper can safely take all his or her luggage without a trailer. It is also less vulnerable to theft.

  • The lighting is good, even at night – 2 x 150 Lux headlights. Plus LED rear lights. Some owners install additional front and rear lights; it’s a “fast Christmas tree” on the road!

  • The visibility in orange is good, perhaps better than the average Sun Tripper.




Everything I learned about the Quattrovelo

Quattrovelo solar hi speed

2020 Quattro Velo Velomobile Walkaround 2019 Eurobike

I bought a Quattrovelo – This Will Be My Next Velomobile

Velomobile speed with load and strong wind

Velomobile holiday in Quattrovelo

Winter Velomobile Ride to Nordkapp – Alve Henricson

Alpha 7 fitting with Quattro Velo, Evo K and Carbon Quest



Velomobile Electric Assist, Speed Test


Solar Powered E-Bike (Trike) Designed to Reduce City Traffic

Ligmotor van Allert Jacobs / Feetforward streamliner

Ebike Solutions 2013 – On the road with my velomobile

Ride in my electric dfxl Velomobile, Garmin 360 degree

Flexible solar panels

Flexible low-cost solar power by Kolon Industries

PowerFilm Lightsaver ultralight solar USB charger

5 Best Flexible Solar Panels (Dec. 2019) –

PowerFilm Lightsaver ultralight solar USB charger

Manufacturing PowerFilm Solar Panels

Roll to Roll Solar Cell Printer

Solar panel support

Velomobiles general

Ask me why I am a velonaut

How Fast a Velomobile is Compared to Upright Road Bike?

Nicola Walde: Velomobile World Record

Velomobil Topspeed 104

108km/h velomobile DF

Commuting with Quest velomobile

How to Choose Which Velomobile to Buy?

What is a Velomobile?

Spezi 2017 Germersheim –


CyclesJV & Fenioux – Vélomobiles et vélos spéciaux

Velomobielworld Alpha 7

The Velomobile

Sustenpass Abfahrt

Hybrid Cab Bike Hawk

Joy of commuting by adding pedals to fast EV

Schwalbe Tryker Rolling Test – Velomobile Tyre Test

How to Buy a Velomobile? – Top 15 Models

Cycling in the Rain – A Wet Velomobile Ride


Oval sprocket; faster

Peregrin on a Birk


Production in Romania


In short, we think a Solar Velo could smash all current records on the Sun Trip solar bike race to China, and One Planet would love to find a partner somewhere who will pick up the challenge with us. We do this because we like to promote modern fossil-free mobility and the Solar Velo can serve as an inspiring and adventurous example!

Contact: Paul Heistein, Tel: +31 6 5240 1947,

One Planet Foundation, Stationsplein 16, 3818 LE Amersfoort, The Netherlands, Tel: +31 33 7370 652

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