OpenIDEO is an open innovation platform. Join our global community to solve big challenges for social good. Sign Up / Login or Learn more

Disruptive Green Taxis [UPDATED 3 Feb 2015]

Taxis based on Solar energy, Biofuels and Kinetic energy! Two complementary approaches: (1) creating retrofitting kit for existing vehicles (tuk-tuks, taxis and buses); and (2) designing brand new green taxis.

Photo of Ramiro Sanchez Caballero
69 17

Written by

Yellow Taxis in New York, the ‘Colectivos’ Buses in Buenos Aires, the ‘motor-rickshaws’ in Beijing or the ‘Tuk-Tuks’ in Bangkok -- every big city has its own public transportation method running on fossil fuels. To make public transportation greener, the idea is to design a Retrofitting Kit for those vehicles that will include: 
a) Roof Panels: Solar panels to be attach on the bus’ or car’s roof generating electricity for their internal needs (light, music, GPS, etc).
The Kits for the Tuk-Tuks will have ‘Black Receptacles’ instead of solar panels, since they are cheaper and are also a durable way to warm up the veggie oil and reduce its viscosity. (See picture attached) 
b) Information Booklet: detail explanation on how to start using biofuels, including a matrix with the different fuel alternatives and their advantages (see picture attached)
c) Stickers: branding that lets potential passengers know the ride is "100% Green" or "This Tuk Tuk Runs on Vegetable Oil" 
The idea is to design a Green Taxi for big cities. Instead of burning fossil fuels, it would have a hybrid motor that will be even more efficient working through:
a) REGENERATIVE BREAKING: As every conventional hybrid motor, the Green Taxis will be charged by using the regenerative braking technology.
b) SOLAR: The Green Taxi will have solar panels on the roof connected to the hybrid motor, which will work in combination with the regenerative breaking system.
c) KINETIC: The Green Taxi will have ‘bicycle pedals’ through which the driver can charge the hybrid motor even further.
d) BIOFUEL: Instead of using fossil fuels for the internal combustion engine, it will run on vegetable oil/biofuels.

i) Start with the retrofit kit (approach 1) in developing countries: test the Tuk-Tuk version in India, and expand it across cities which can see the value of using a cheaper and greener fuel alternative.
 ii) Develop the brand-new taxis (approach 2), which should be more cost-effective but imply a bigger out of pocket expense. We would start by transforming lightweight Tuk-Tuks into hybrid vehicles.
iii) Consider launching the new taxis (2) in developed nations. This time instead of being similar to the Tuk-Tuks, it would look like a conventional car.
*When it comes to designing a new car, we should consider forming an alliance with existing players (both for cars and tuk-tuks).
Once the design and prototype are done, there are some elements we need to consider in our go-to-market strategy: 
a) Get EPA on board: Vegetable oil or recycled greases are not registered by EPA for legal use in motor vehicles and you can be slapped with heavy fines. 
b) Test the Product: we should start in a developing country with the retrofit kits. India is a big market where we could fully exploit the Green Taxis. The idea is to start in a mid-size Indian city and afterwards expand into other developing countries 
c) Network: we could get Uber onboard! Uber is going international and could make it easier to get the green taxis into developing countries, leveraging their market and network. Uber has been doing small charity too. 
d) Funding: we could get Google onboard! The Google self-driving car means they already have the engineering expertise, not to mention the funds and the reputation as an innovator to drive this project forward. Another alternative could be ‘Local Motors’ a motor vehicle manufacturing company focused on low-volume manufacturing of open-source motor vehicle designs using multiple micro-factories. 
e) Safety concerns: each green taxi alternative will have the same safety features as the local vehicles have.
f) How to get veggie oil? Vegetable oil is obtained from the waste of restaurants or house kitchens. But veggie oil waste is getting quite demanded, so, in order to obtain it, litters of oil could be used as currency for rides. 

Vegetable oil as fuel
Diesel engines can use vegetable oil to work with no other modifications. However, vegetable oil has very high viscosity. It's so thick that the engine has a hard time atomizing the fuel completely when it is sprayed into the combustion chamber. The result is unburned fuel that clogs the engine.  To avoid this, the solar panels heats up the veggie oil, turning the semi-solid oil into a warm liquid that can be atomized more effectively. Also, the bicycle pedals would start-up the engine, since those first combustions are the most critical for the engine.  


What community does this idea benefit and who are the main players?

[updated 2/3/15] Commuters have to use vehicles that run on fossil fuels. The only green alternatives are to walk or to ride a bike, but these are not always viable alternatives. With the Green Taxis, commuters have the possibility of using an environmentally friendly and convenient vehicle. It also allows drivers to make a low investment to improve their vehicle, saving on variable costs and attracting new customers. Big cities would benefit the most from this idea, since: 1) would be easier to get veggie oil waste and biofuel; 2) there is a high demand for transportation; 3) these green taxis are much smaller than cars (useful when there is high traffic); 4) tourists will seek will see it as a novel idea.

How does your idea specifically help your community rapidly transition to renewables?

[updated 2/3/15] The Green Taxis empower people to make choices by themselves. On the one hand, taxi drivers have the possibility of choosing the biofuel they prefer and combine it with other methods (solar and kinetic). The retrofit kit gives them the power to build their own green taxi, buses and tuk-tuks. On the other hand, users have the power choose how commute greenly. This idea helps the whole community transit into renewables since it offers each player incentives to use the product (drivers reduce their variable costs and users breath less pollution).

What early, lightweight experiment can you try out in your own community to find out if the idea will meet your expectations?

[updated 2/3/15] The Retrofit Kit is very tangible and can be quickly tested and proven on a small scale whether it has potential to be replicated in other communities. A prototype could be made easily since every part of it already exists: it would be just attaching solar panels to a bus or black receptacle panels to a Motorized diesel bicycle. Using biofuels such as veggie oil has already been proved to work on diesel engines. These kits are both doable and actionable. On the other end, the Green Taxis require more analysis and investment, hence the idea is to find a partner. The lightweight prototype can be made by combining the hybrid motor to the solar panel and the bicycle pedals to combine the energy generation.

What skills, input or guidance are you keen to connect with from the OpenIDEO community to help you build out or refine your idea further?

Experts in car engines and mechanics.

Please indicate which type of energy is most relevant to this post:

  • Electric vehicles

This idea emerged from:

  • A Group Brainstorm


Join the conversation:

Photo of Robert Hieger

I am a grad student at NYU Polytechnic School of Engineering, Integrated Digital Media program, with a focus in Web Design/Development and applications.

I am truly encouraged by the concept of green taxis, and speaking as a resident of New York City, it is an idea whose time has come. I have long been passionate about the perils of global warming.

The ideas proposed here seem quite sensible and even provide incentives to local business, such as restaurants who need to dispose of their waste vegetable oil. This would effectively transform their waste into fuel.

It would seem the greatest obstacles are lack of information to the uninformed, and disinformation at the hands of those who stand to gain most from hindering renewable energy sources--that is, the fossil fuel companies.

One wild and perhaps naive question I would pose is this:

Is there a way that we can make renewable energy attractive to fossil fuel interests? If so, it would seem there would be enormous funding pools potentially brought to bear.

Perhaps an even more naive question is this:

I seem to recall quite a lot of talk in alternative energy circles about hydrogen cells powering cars. Ostensibly, the only byproduct of this energy is water vapor. Am I misinformed on this, or is this not a practical avenue of pursuit in the powering of motor vehicles?

I will follow this challenge with great interest. I hope to be able to contribute, even in some small way, before the challenge reaches its conclusion.

My hearty vote of confidence and admiration to all those involved in this challenge.


Robert Hieger

Photo of Ramiro Sanchez Caballero

Hi Robert, thanks for your comment!
we will definitively include information for the user, apart from the matrix attached and the steps to adapt the use, what other thing do you consider necessary?

hydrogen cars are a really interesting alternative, but don't know in what stage they currently are, do you have any information?

Feel free to continue posting ideas, there are only 6 days left until the end of the refinement stage, so any feedback is welcomed!

Photo of Joanna Spoth

Robert, excited to hear more of your feedback on this idea. I think you and Ramiro could form a powerful collaboration!

View all comments