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Sustainable Energy For Future Transport

There has been a lot of discussion in the automotive industry about the investment and development of alternative energy in transport. As more stringent requirements from global standard authorities make efficiency and minimal pollution a more weighted consideration in new vehicle design, should we be anticipating the obsolescence of the internal-combustion engine anytime soon? This article aims to give a brief overview of the considerations for the automotive sector and the surrounding community concerning the adoption of alternative forms of energy given the strain on and negative impact of current resources. 

Fully electric systems

It is very easy to adopt the idea that the electric car will be the future of motoring because of the massive potential electric motors have over conventional engines. The mechanical simplicity of the electric motor does away with complex transmissions, timings and air induction systems in favour of better performance, efficiency and maintainability. However, the progress of electric car development is a frustrating topic because of the short-falls in battery technology, this includes charging times, energy density, longevity and an immature electric grid that still relies on fossil fuels. Although there is a great deal of global investment in these issues, it is hard to predict a time-scale for mass-adoption while the market is still waiting for a “battery revolution”.


Renault Zoe Electric Sport Concept

The requirements for renewable energy sources for electric vehicles is an important sustainability factor with energy and transport pollution constituting 51% of total produced greenhouse gases according to the UK government's 2016 report and if electric cars are to make any impact on this statistic then their energy needs to come from clean sources. Current energy production techniques are inefficient and suffer transmission losses currently making electric cars only slightly less polluting than conventional engines, the ideal solution to this problem then would be to use a localised source of electric power, perhaps through forms of directly integrated renewables.


World Solar Challenge Challenger Class Vehicle

The “World Solar Challenge” has been experimenting with the use of direct solar power to try and find a feasible solution to this idea, but with stringent requirements for lightweight materials, favourable weather conditions and high battery charge-density currently makes them very inconvenient for scalable use. However, these solar power systems could be useful in future dual charging systems to ease loading on the electric grid.  

Hybrid electric systems

With the development of fully electric systems still in their infancy, hybrid systems have become an effective compromise as a localised electric source to maximise energy efficiencies and improve range greatly, even by conventional standards. However, fossil-fuel hybrids still do not solve the underlying sustainability issue and with the associated increase in required materials, drivetrain complexity and weight making cars bigger, is it fair to say this is not a viable long-term solution?


BMW i8 Hybrid

However, if localised electric generation using expendable fuel can be considered progress, then perhaps there should be more investment in fuel cell technology. As a prospective replacement for batteries, hydrogen fuel cell technology is a strong candidate for use in transport because of its competitive range capability, longevity and remarkably clean emissions, where hydrogen gas is reacted with atmospheric oxygen to make H2O… water! However, even though the process can be completely renewable through electrolysis and viewed as a theoretically perfect solution, the reality is once again frustratingly underdeveloped. With an immature refuelling infrastructure, hydrogen production techniques that still favour fossil fuels and the requirement for cheaper fuel cell electrodes, we should hope to see more pressure for its development in the near future. The Asian car making industry has already seen some investment in this technology already with Toyota’s “Mirai”, Honda’s “Clarity” and Hyundai with its modified ix35 all showing very competitive performances, hydrogen could yet supersede the use of batteries in electric cars of the future.


Toyota Mirai Hydrogen Fuel Cell Vehicle

Fuel cells have also been used in range extenders for fully electric vehicles, alongside conventional petrol generators, turbines and heat-engines to top-up batteries when they start to run low. The difference from a conventional hybrid system being that the generator is not connected to the drivetrain. UK truck manufacturer Tevva Motors has developed a range extended glycerine powered electric truck that can do competitive mileage for urban courier work which is currently under trial with UPS. This is an excellent example of a small OEM taking the initiative to discover, research and develop completely new options to share in the industry's future.

Alternative internal combustion

There have been a number of options discussed so far for the environmentally concerned but none really address the issue of economics. While a lot of new cars will save on running costs, the initial outlay for new electric cars and some hybrids will not give any significant return on investment which is enough to dissuade most consumers, even with government grants and zero road tax. Motoring is expensive enough so why would you pay more for less, is there simply a way to make existing engines as green as electric motors by using existing technology and infrastructure?

Actually, cleaner forms of hydrocarbon fuels can be found from a variety of abundant natural sources that can be used as part of natural carbon cycles. Natural gases such as methane can be collected from animal waste and burned to create carbon dioxide and water, other sources also include sewage and landfill which would otherwise be released into the atmosphere as wasted energy. By modifying existing combustion engines for use with gas, methane can be used as a less toxic replacement for petrol. The “Bio-Bug” developed by British firm GENeco is a modified Volkswagen Beetle that runs very efficiently on human waste and as a methane concept car, has the potential for commercial scalability where it’s only limiting factor would be the modification of the engine to run on compressed gas.


Methane Powered Volkswagen Beetle

The concern with methane is where it comes from animals that cannot recycle the carbon that they produce and because of this plant based bio-fuels are seen to be a friendlier option where natural carbon-storage is enabled through photosynthesis. Crops such as palm and oilseed-rape have been used to create cleaner synthetic fuels from the plant oil they produce, while high carbohydrate crops such as sugarcane, corn and potato can also be used to create alcohol based fuels from fermentation processes. There has been controversy surrounding the feasibility of this solution where it could interfere with food production, lead to deforestation to increase crop-growing land and with its realistically non-perfect carbon cycle, dry-crop bio-fuels seem to have plateaued in recent years. However, this recess may be filled with the future development of algae based biofuels that are said to have order of magnitudes higher oil-yield compared to conventional crops and can be grown on unused land. With feasibility studies for commercial-scalability still in progress it seems like it could still take a number of years before we see algae based bio-fuel on a global scale but it certainly has a lot of potential. 


A few conclusions can be drawn from the current state of alternative energy in transport. A problem common to all of the solutions is the underlying immature infrastructure and economy that still stubbornly relies on fossil fuels. In the UK renewables equate to around 30% of the power infrastructure which is excellent but makes the investment in electric cars currently seem like a false economy. As this figure improves we should hope to see advancements in electric technology that makes their investment more viable.

The consideration for further investment in alternative renewable fuel production is also important especially for candidates such as hydrogen where it produces zero carbon dioxides and nitrous oxides which will help improve air quality and general health. If it were easier to run cleaner, more efficient alternative fuels using existing vehicle designs while electric cars and renewable infrastructure improve, foreign oil dependency would decline in favour of cleaner, more affordable and decentralised sources. Replacing fossil fuels would require very little investment in new logistics and pumping infrastructures where the fuel is similar in composition but with fewer toxic elements and particulates which have been a concern recently with the otherwise more efficient diesels engines.

As discussed in this article there is an array of sources for the automotive sector to draw from, with further investment in STEM based education and the added growth of the internet and maker communities there is a lot of potential to develop and share the solution with the world for the sake of its sustainable future.

A keen maker and electronic engineer with a passion for the environment, renewables, alternative transport and anything off-grid. Man with a van and founder of the Kickstart Kamper sustainable campervan project. Grassroots Education Sustainability Ambassador. BrightSpark 2017. BEng.