FAQ - Solar Bicycles 

Frequently Asked Questions (FAQs) on Solar Bicycles

FAQs covered in Our Other Pages:

Q1. What is a Solar Bicycle? 

Q2. Why Bicycle Trails?  Benefits of Multi-modal Streets (The Netherlands' Model)

Q3. Why Solar Bicycles?  Represents Smallest Footprint

Q4. What is 'The Netherlands' Model'?   - a Bicycle and Public Transport Model with Multi-modal Streets 

Q5. How did the Netherlands become a Bicycling Nation? Learn and try to replicate it.

Q6.  Disrupting the USA (Private Car) Model? Solar Bicycle reaches American Shores Alexandria, USA  

Q7.  Countrywise Carbon dioxide (CO2) emissions?

Q8. Are 40W Solar Bicycles more effective  than  4 kW Solar Rooftops to curb CO2 emissions?

Q9. Solar Bicycles vs EVs. Differences? The Need to promote Solar Bicycles

Q10. Are you best suited to Ride a Solar Assisted Bicycle? Criteria to be a happy owner of a solar assisted bicycle 

Q11. How To Understand The Impact Мultimodality In Transportation Has On Cities Of All Sizes? 

FAQs covered in this Page below:

Q50: Which is better for the environment -  Solar Assist Bicycles or regular Bicycles? 

Q51: How much benefit would Solar Assist Bicycles offer over normal Bicycles? 

Q52: How to get a better mileage on a Solar Bicycle? 

Q53: What are the similarities and differences between a Solar Assist Bicycle and a Geared bicycle? 

Q54: What are the benefits of Gears in a Geared Solar Assist Bicycle? 

Q55: What are the different operational modes of a Solar Assist Bicycle?

Q56: How to get better mileage on a Solar Bicycle? 

Q57: FAQs and Road Safety Tips for Teens to Prevent Accidents

Q58: Which are the more efficient Human Propelled or Motor Assisted modes of transport? Compare them in terms of metabolic energy? 

Q59. Why is the solar assist bicycle considered to be the best personal transport vehicle for climate change?

Q50: Which is better for the environment -  Solar Assist Bicycles or regular Bicycles? 

A: Metabolic energy is obtained from the food that one eats; hence, is generated from fossil fuels and contributes to global warming. 
Moreover, the human body is an inefficient machine with only 24% of the energy delivered to perform the work - pedal and propel the bicycle. Hence, even more metabolic energy gets wasted,resulting in even more carbon footprint, contributing to even more global warming.
On the other hand, the energy that earth receives from the sun, is called solar energy. Since, it is a renewable source, it does not directly contribute to global warming. A photo-voltaic panel facing the sun harnesses part of the solar energy falling on it. 
Hence a solar assist bicycle is much better than a regular bicycle, even from the environmental point of view.        

Q51: How much benefit would Solar Assist Bicycles offer over normal Bicycles? 

A: To achieve a steady speed of 18 km/hour,  the rider would need to expend 430 kcal  or = (430/0.86042) Wh = 500 Wh of metabolic energy per hour. 

• Considering the human efficiency of 24%, this translates to (430/3.585) = 120 Wh of energy at the pedals or wheels In the case of a solar assist bicycle, the 120 Wh of energy at the wheels is offered by the BLDC hub motor. 

• From a 40W solar panel, with good sunshine, it is possible to tap about 36W of solar power. Hence the balance (120 - 36) = 84 Wh = 84 x 3.585 = 301 kilocalories needs to be offered by the rider. 

Thus, the 40 W solar panel helps in reducing the rider's metabolic energy from 430 kcal to 301 kcal or a 30% savings in metabolic energy.  The 40W solar panel substitutes upto 150 Wh or 129 kilocalories of metabolic energy.

• The above calculations are for solar assist mode where both the rider and the solar panel share the energy requirement. No battery energy is consumed in this mode, hence, there is no distance limit as long as the rider continues to pedal.  

The solar assist mode makes it easy for the rider to pedal. Instead of pressing hard on the pedals, the solar energy makes riding effortless and enjoyable. 

• By tapping solar energy directly from the panel, and additionally solar energy that was previously stored in the battery, the rider can choose to make the ride even more effortless while pedalling in the solar assist mode.
  However, in this case, the battery does get discharged and the distance range can drop down to 30 km. 

• If the rider wishes to extract maximum benefit - the throttle mode is always available where the rider does not pedal and the entire energy is offered from the battery and the solar panel. However, the battery would get discharged at the maximum rate in this mode and the distance range would drop down to typically 15 km. Cruise mode is a special mode under throttle where the rider can travel at a steady constant speed that can offer slightly better efficiency (range is typically 20 km) 

Q52: How to get a better mileage on a Solar Bicycle? 

A: It depends on the riding style:

•  Do not Accelerate on Power Modes: The rider should not use either throttle or pedal assist (keep the switch off) while accelerating - a situation typically observed when one mounts the bicycle for the first time, 

• Cruise Control: In the throttle mode, the rider should ride in the 'cruise mode' at a steady speed. 

• Choose Lower Solar Assist Setting: If the rider is in the solar assist mode, then choose a lower setting, say 2/5 for a 5 speed solar/ pedal assist model

• Choose Lower Speeds: Try to ride at a lower speed, so as to prevent unnecessary braking.

• Keep Solar Panel Clean: Keep the solar panel clean by wiping the top glass with a wet cloth.

• Inflate Tires till Hard: Keep the tires of the bicycle properly inflated - inflate till hard when pressed between the fingers. Inflate till 40 psi.

• Panel to face the Sun: Park the bicycle on the Center Stand in such a manner and direction that the solar panel is facing the Sun and with direct rays falling on it, so that the solar panel is able to harness maximum energy from the Sun. You would know if the direction of the parked bicycle is set correctly by observing the shadow. The area of the shadow should be minimum and it should fall below and symmetrically on either side of the bicycle       

The solar bicycle will cover significantly more (almost twice) the trip distance if the above tips are followed.

Q53: What are the similarities and differences between a Solar Assist Bicycle and a Geared bicycle? 

A: Similarities: 

• Both a Solar Assist Bicycle or a Geared Bicycle offer  mechanical advantage while pedaling. As a result, the effort that the rider has to put in, while pedaling,reduces. This makes pedaling appear effortless, or light, or more enjoyable to the rider. 

• Geared Bicycle: The lower the Gear level, the more the mechanical advantage. At Gear Level 1, the mechanical advantage is maximum, while at Gear Level 7 (topmost level) the mechanical advantage is minimum (least). Shift to a lower gear to get more mechanical advantage or to a higher gear to reduce the mechanical advantage. 

• Solar Assist Bicycle: The higher the solar assist level, the more the mechanical advantage. At Solar Assist Level 0,  there is zero assistance/advantage, while at the Solar Assist Level 5 (topmost level) there is maximum solar assistance/ advantage. Shift to a higher level to get more solar assistance or to a lower level to reduce the solar assistance.

Differences: 

• Geared Bicycle (without Solar): Assuming gears to be on the rear sprocket wheel (cassette or freewheel), in Gear Level 1, the chain would be riding over the largest diameter rear sprocket wheel. Hence, in Gear Level 1, for each rotation of the front crankset or chainset (crank arm + chain wheel), the rear sprocket along with the rear wheel rotates less, resulting in less distance being traveled in comparison to any of the higher gears, say Gear Level 7. When you shift to a lower gear level, for the same speed of the crankset, the speed of the bicycle drops. Hence, the mechanical advantage offered to the rider (to pedal with less effort) is at the cost of the speed of the bicycle or travel time; it takes more time to reach the destination.  

• Solar Assist Bicycle: Unlike an ordinary geared bicycle (without solar assist), in the case of a solar assist bicycle the rider gets to choose to inject more or less solar energy along with his own metabolic energy to propel the bicycle forward. By shifting to a higher solar assist level, the rider is able to conveniently lower down his own metabolic energy or lower down the effort or burn less calories from his own body. Thus the increased mechanical advantage or increased solar assistance provides the rider the ability to ride with less effort (effortless) while observing no speed reduction. With solar assist, the rider has an option to put in less effort and yet reach the destination on time.
  Alternatively, if the rider is willing to put in the same effort, then by increasing the solar assistance, one can ride at a higher speed at a higher solar assist level, and reach the destination in a shorter time. 

Q54: What are the benefits of Gears in a Geared Solar Assist Bicycle? 

A: Having understood (answer linked to the previous one above) the differences between an ordinary geared bicycle and a solar assist bicycle, we will be able to appreciate the benefits of having both types of effort reduction techniques in a single bicycle. 

If the rider wishes to reach his destination in the shortest possible time, he needs to ride at 25 km/hour  (permitted top speed for bicycle trails or bicycle lanes) instead of the typical average speed of 15 km/hour. To do this without increasing his pedaling effort - he can shift to a higher solar assist level - say from solar assist Level 2 to Level 3. However, in this new state, though the pedaling effort has remained constant, the pedaling speed or speed of rotation of the  front crankset (crank arms-chain wheel) has increased along with the speed of the bicycle. The increased pedaling speed may make the rider less comfortable. Hence, in the higher Solar Assist Level, by shifting to a higher gear, the pedaling speed can be reduced without affecting the bicycle speed or the rider's effort (metabolic energy). 

Hence, for a thrilling, comfortable and enjoyable ride experience, high bicycle speeds can be achieved without increasing the rider's effort (metabolic energy), with a combination of a higher Solar Assist Level and topmost Gear Level. 

Thus with a geared solar assist bicycle the rider is able to comfortably and effortlessly achieve the top speed of 25 km/hour to reach his destination in the shortest possible time. It is the best powered vehicle for those who value their own time and yet wish to have a daily routine schedule to burn calories in a controlled manner causing minimal environmental damage.    

Click here to visit our geared solar bicycle page

Q55: What are the different operational modes of a Solar Assist Bicycle?

A: A solar assist bicycle can be operated in:
1. Solar Assist Mode - Mix and choose a combination of your own metabolic energy, solar energy and stored battery energy to pedal in an assisted mode for comfort, pleasure, joy and speed.
  Different solar assist levels and gear levels and their combinations are available to suit the rider's comfort and effort levels. 

2. Manual Mode - Choose Solar Assist Level 0 to pedal like a regular bicycle (without assistance). But with safety features - such as headlights, tail-lights, brake lights, horn, LCD Display for speed, battery voltage, etc. 

3. Throttle Mode  -  propelled primarily by the stored battery energy. Limited solar energy is also used if available (daytime).
3a. Cruise Mode - a special mode under throttle - to maintain constant speed and use the battery cum solar energy in a more efficient manner than with a manually operated rotating throttle handle. 

A solar assist bicycle has been designed to be primarily operated and used in the Solar Assist Modes  (including Mode 0 Manual Mode), and rarely in the throttle and cruise modes. 

Q58: Which are the more efficient Human Propelled or Motor Assisted modes of transport? Compare them in terms of metabolic energy? 

A: As per literature, electric unicycles (EUC), velomobiles (enclosed recumbent bicycles) and electric bicycles, in decreasing order are the most efficient modes of human transport. However, from the environmental angle, the solar assist bicycle is the most efficient.  

 To cover a distance of 1 km, cycling (bicycling) would consume the least metabolic energy compared to other modes of transport like walking, running, or driving a car, as it is considered one of the most efficient forms of human-powered transportation. To cover 1 km -  

• Walking / Running: A good heuristic for calories burned while walking / running is 1 kilocalorie per kilogram per kilometer. A person who weighs 63 kg would burn about 63 kilocalories per kilometer walked/ run.

• Bicycle: A standard lightweight, moderate-speed bicycle is one of the most energy-efficient forms of transport. A rider weighing 63 kgs riding at 18 km/h would expend about 24 kcal/km or (24/0.86042) Wh/km =   27.89 Wh/km (of metabolic energy per kilometer). Thus, when compared to walking, bicycling requires about 38% of the food energy per unit distance. Considering the human efficiency of 24%, this translates to (24 x 0.24) = 5.76 kcal/km = (5.76/0.86042) = 6.69 Wh/km of energy at the pedals or wheels. 

• Solar Assist Bicycle: The 6.69 Wh of energy at the wheels is offered by the BLDC hub motor. From a 40W solar panel, with good sunshine, it is possible to tap about 2.0 Wh/km of solar power over 03:20 mm:ss (time required to cover 1 km). Hence the balance (6.69 - 2.0) = 4.69 Wh/km (4.035 kcal/km) at the wheels needs to be offered by the rider. Again considering a human efficiency of 24%, this reflects as  = 4.035/ 0.24  = 16.81 kcal/km of metabolic energy to be offered by the rider. Thus, the 40 W solar panel helps in reducing the rider's metabolic energy from 24 kcal to 16.81 kcal or upto 30% savings in metabolic energy.  

The 2.0 Wh/km of solar power from 40W solar panel substitutes 8.35 Wh/km or upto 7.19 kcal/km of metabolic energy. As long as the rider is willing to expend the balance 16.81 kcal/km, the solar assist bicycle has no distance barrier, unlike other EVs (electric vehicles). However, if the rider is interested in expending energy even lesser than 16.81 kcal/km, by choosing a higher pedal assist mode, then the difference can be filled in from the energy stored in the battery. For instance, 2.0 Wh/km from solar and another 2.0 Wh/km from the battery would result in a more comfortable (6.69 - 2 - 2) = 2.69 Wh/km at wheels or 11.21 Wh/km (or 9.64 kcal/km) or 40% of metabolic energy expended. 

Of course, the throttle mode is always available where the rider does not pedal and the entire energy 6.69 Wh/km is offered from the battery and solar panel (0% of metabolic energy). It should be noted that, in the throttle mode, the rate of discharge of the battery would be maximum and the distance covered would be minimum.  

59. Why is the solar assist bicycle considered to be the best personal transport vehicle for climate change?

A: A solar assist bicycle is one of the most efficient man-made personal transport vehicles consuming only 6.69 Wh of energy per kilometer for propulsion at the wheels of which upto 2.0 Wh/km can be generated from the solar panel while in motion.
Metabolic energy is equivalent to fossil fuel energy in terms of CO2eq. The solar assistance can help reduce the rider's metabolic energy by upto 30% (from 24 kcal/km to 16.81 kcal/km). It can offer unlimited distance coverage as long as the rider is willing to expend 16.81 kcal/km. Since the  2.0 Wh/km of solar substitutes 8.35 Wh/km or 7.19 kcal/km of metabolic energy, it also offers a corresponding saving of  CO2eq, in comparison with every kilometer of travel over a regular un-motorised bicycle! 
The rider can choose to make his ride even more comfortable by selecting a higher pedal assist mode or even the throttle mode and allowing the battery to deliver the stored energy. In such a case, the ride is even better from the environmental point of view - since the energy consumed from the battery represents solar energy. The metabolic energy is substituted by the solar energy and this represents a corresponding saving in CO2eq. Hence, the solar assist bicycle is considered to be the best vehicle from the point of view of climate change.   

Table showing break-up of Metabolic and Solar Energies consumed by Bicycle (in Wh/km) for Unlimited Range 

Table showing break-up of Metabolic and Solar Energies consumed by Bicycle (in kcal/km) for Unlimited Range 

Table showing Comparison of Metabolic, Battery and Solar Energies consumed by a Bicycle (in Wh/km) for Range limited to 30 kms in a Typical Solar (Pedal) Assisted Ride Mode