Why Solar Bicycles?
What is a Solar Bicycle?
A solar bicycle is a Hybrid Electric Vehicle (HEV) that uses solar photovoltaic generator to charge a battery and/or power an electric motor to propel the bicycle. One can ride a solar bicycle in three different modes - (1) Manual mode using pedals (metabolic energy), (2) Battery mode - by rotating a throttle handle, and (3) Solar Assist mode - where the solar energy is used to assist the rider in making pedaling lighter (requires less effort) and more comfortable; and the ride experience - enjoyable and more pleasurable.
Though it is designed to be normally used in the solar assist mode, the other modes are also available to suit the user's needs depending on circumstances and external conditions. There are multiple levels of solar assist (typically five) in the solar assist mode, and by choosing the correct level, one can extract just the right amount of solar assistance needed without causing battery drain.
On using the throttle mode, if the battery does get drained, then the battery charge can be restored by simply parking the bicycle for a few hours (typically 3 - 4 hours) under direct sunlight and with the solar panel facing the sun for best results. Under these conditions, since the source of energy is the sun, there are no fossil fuel emissions unlike other HEVs or Battery Electric Vehicles (BEVs).
At times (when there is no sun-shine) a solar bicycle can be operated as a Plug-in hybrid electric vehicle (PHEV) or as a BEV whose batteries can also be charged by plugging the vehicle into an AC mains power source. On such occasions when there is dependence on the regional electricity grid, we cannot consider the bicycle to be emission free.
Usually we don't account for human energy while considering green house gas (GHG) emissions. Actually, human calories burnt which is typically 75 kilocalories per hour when sitting idle or 350 kilocalories per hour when manually pedaling a bicycle, also contributes to global warming. Riding a solar bicycle in the solar assist mode actually lowers down the consumption of human calories and therefore can also be viewed as beneficial for mitigating climate change.
Battery electric vehicle (BEV): BEVs are powered by electricity, which is stored as chemical energy in batteries. The energy powers an electric motor that propels the vehicle.
Why Bicycle Trails? Benefits of Multimodal Streets (The Netherlands' Model)
Road fatalities (0.15 million/annum) or (1 in 10,000 population) in India is the highest in the world. If we, in India, wish to take important matters such as the quality of human life, or assign a higher value to human life, we need to start by studying the streets of other countries. We believe that it would be a waste of energy to educate the public about following traffic discipline to reduce the fatalities. It would makes better sense to choose the correct model and approach the authorities and decision makers after an analysis, study, debate and a pilot.
India is currently following the US (private car) model, while the rest of the world (even US is beginning to) is following the Netherlands (public transport and bicycle) model with multimodal streets.
Streets must be designed to serve different modes and provide multiple mobility options for its users.
Multimodal streets offer people options for safe, attractive, and convenient travel by foot & bicycles, on transit, as well as in motorized vehicles. Multimodal streets help to make cities more efficient. A reduction of private cars on streets has a direct link to reduced production of greenhouse gases, related to climate change. This shift also helps in increasing space for commerce and public use, and contributes to a better quality of life and economic growth.
For more details on Multimodal streets and their benefits, click here.
Why Solar Bicycles? Represents Smallest Footprint
A solar bicycle is a result of extreme engineering. It represents a personal mobility vehicle for commute and cargo with the smallest footprint in many aspects and categories. In terms of carbon footprint, the manufacturing emissions (< 160 kgCO2eq. in comparison to 10 tonnes CO2eq. for cars). Physical dimensions - solar bicycle: l x b x h = 195 cm x 65 cm x 110 cm vs. an SUV : l x b x h = 500 cm x 200 cm x 160 cm. Weight - under 30 kg for a solar bicycle vs > 2000 kgs in case of an SUV. Fatalities (death on bicycle lanes < 0.01% of those on roads built for cars, of equal lengths. Speed 25km/hour for a solar bicycle vs 120 km/hour for an SUV. Power sink (motor < 300W), in comparison to 1600 cc engine or 40kW motor in the case of an SUV. Power source (40W solar panel of solar bicycle) vs. gasoline or electricity in case of an SUV, represents a savings of 0.133 kg or 0.08 kg of CO2eq for every kilometer of travel with a solar bicycle that substitutes an ICE or electric SUV respectively).
A solar assist bicycle is the most efficient man-made personal transport vehicle consuming only 3.2 Wh of energy per kilometer. It can offer unlimited distance coverage, by tapping about 1.7Wh / kilometer of energy from the solar panel on a continuous basis. The solar assistance can help reduce the rider's metabolic energy by 53% from 11.6 kcal to 5.5 kcal/km. Since the 1.7Wh/km of solar substitutes 7.1 Wh/km or 6.1 kcal of metabolic energy, it also offers a corresponding saving of CO2eq, in comparison with every kilometer of travel over a regular un-motorised bicycle!
With the addition of 24.5 GW of new solar power capacity in 2024, India's total installed renewable energy (RE) capacity reached 209.44 GW as of December 2024. Solar energy accounts for approximately 47 percent of the total RE segment, making it the most significant contributor among renewable sources.
India added around 18.5 GW of new solar capacity, in 2024, an increase of 280 per cent over 2023, in the utility-scale solar segment. The surge in the solar power sector is mainly attributed to the falling module prices and subsequent growth in the commercial and industrial sector installations.
India added around 4.59 GW of new solar capacity, in 2024, an increase of 53 per cent, in the rooftop solar sector, thanks to the launch of the 'PM Surya Ghar Muft Bijli Yojana'. Also in the off-grid or distributed segment, solar capacity of 1.48 GW was added in 2024, and increase of 197 per cent.
List of countries by CO2 emissions
China, the United States, India, the EU27, Russia and Brazil were the world’s largest GHG emitters in 2023, accounting for 49.8% of global population, 63.2% of global gross domestic product, 64.2% of global fossil fuel consumption and 62.7% of global GHG emissions. Among these top emitters, in 2023 China, India, Russia and Brazil increased their emissions compared to 2022, with India having the largest increase in relative terms (+ 6.1%) and China the largest absolute increase by 784 MtCO2eq.
Since 2006, China has been emitting more CO2 than any other country. However, the main disadvantage of measuring total national emissions is that it does not take population size into account. China has the largest CO2 emissions in the world, but also the second largest population. Some argue that for a fair comparison, emissions should be analyzed in terms of the amount of CO2 per capita. Their main argument is illustrated by CO2 per capita emissions in 2023, China's levels (9.24) are almost two thirds those of the United States (13.83) and less than a sixth of those of Palau (62.59 – the country with the highest emissions of CO2 per capita).
The above table shows that India's CO2 emissions has increased by 197% in 2023 in comparison to the year 2000. India is also having the largest increase in CO2 emissions in relative terms (+6.1%) in 2023 when compared to 2022.
So why isn't the total installed renewable energy (RE) capacity (of 209.44 GW as of December 2024) helping in reducing the CO2 emissions? The answer is simple. The renewable energy is used to fuel additional load from new growth in infrastructure in industrial, commercial, agricultural and residential sectors. The renewables are not at all effective in reducing the fossil fuel consumption of the installations that existed in the year 2000. India is arguing that its emissions should be analysed in terms of amount of CO2 per capita. The growth of India's population is also used as a justification for the increase in India's CO2 emissions. Whatever the reason for the increase in India's CO2 emissions, it cannot be a justification for failure to achieve its goal of net zero emissions in order to limit global warming to 1.5 ℃.
Our analysis of the solar installations show that the government subsidies for solar are causing more damage than good to the environment. The consumers who are opting for solar rooftop installations by availing the solar subsidy are doing so only to offset their more expensive fossil fuel based units imported against the cheaper solar units earlier exported, under the Net-metering tariff . In this manner, the consumer is able to charge their Electric Vehicles at night with fossil fuel based energy from the utility, practically free of cost. The EVs are also available to the consumer at a lower price thanks to the EV subsidy offered by the government. All put together, the consumer is able to significantly reduce his own utility bills and enjoy the luxury of driving an EV, at the cost of the environment. An audit of the consumer's fossil fuel units imported before and after the solar roof top installation would show that the imported units have actually increased post installation. Unfortunately, this audit is never carried out and all that is visible to the happy consumer is the reduction in his electricity bills.
One may argue that the solar units exported by a customer can be used to feed a fossil fuel driven load, hence it would result in reduction in CO2 emissions. This is also not true since maximum solar units are generated and exported usually at noon. The Indian utilities wonder what to do with the excess solar generation that they are unable to store and the best option open to the utilities is to offer them practically free of cost to the agricultural sector where much of the energy goes unmetered and gets consumed on a HorsePower (HP) based tariff. Farmers are often seen to keep their pumps in the 'always ON state' on the agricultural feeders; hence, when they are energised by the utilities with solar energy, this results in overdrawal of water and fall in level of the water table. Fall in water level means that more powerful pumps need to be deployed that consume more energy. Thus it results in more damage in terms of CO2 emissions.
It should be noted that manufacturing solar cells also result in CO2 emissions. Hence, if these CO2 emissions cannot be recovered through the generation of electricity from these very solar cells, then a typical 4 kW solar rooftop installation over a residential consumer's premises that use thousands of these solar cells thus can result in more damage in terms of CO2 emissions, than good.
On the other hand, the solar bicycles that are fitted with 40 W solar panel substitutes an EV (or an ICE engine). The 40W solar panel represents just 1/100 of the 4 kW solar panels that are found over a typical rooftop installation. When the EV or the car with an ICE is parked at home, the solar bicycle rider would be saving in terms of CO2 emissions significantly. Every kilometer run by a solar bicycle represents a direct saving of 0.133 kg or 0.08 kg of CO2eq., assuming that the vehicle that it substitutes is an SUV with an ICE engine of 1600 cc or an electric motor of 60 kWh respectively.