Cleaning up propulsion

Battery- and hybrid-electric, biofuels, hydrogen and fuel cells… growing concerns over the security of energy supply, climate change, and health are driving the shift from fossil to alternative fuels and vehicle propulsion systems capable of delivering long term sustainability.

As sailing boats and bicycles demonstrate, clean mobility is nothing new. Yet since the mid-19th century, the abundance, low cost, and high energy storage capacity of fossil fuels have led to their domination of the transport picture at large, fuelling planes, trains, and automobiles across the globe.

Meanwhile our cities stay on the move through a combination of public and private transportation modes, which combined account for around 40% of emissions from the entire transport sector. And right now the focus here is very much on cleaning up the propulsion systems of buses and cars.

The abundance, cost, and high energy storage capacity of fossil fuels have led to their domination of the transport picture at large, fuelling planes, trains, and automobiles across the globe.

Bettering the bus

In public transport, the cities with the biggest investment clout are where battery- and hybrid-electric buses with plug-in are gaining the most ground.

‘We expect to have 1,700 diesel-electric hybrid buses running through the capital by 2016, when they’ll make up 20% of the whole fleet,’ says Transport for London (TfL), which manages one of the largest bus networks in the world, with around 8,500 vehicles. By 2020, as part of its Ultra Low Emission Zone, the Authority has committed to ensuring all its 3,000 double deck buses are hybrid.

Meanwhile in Paris, transport operator RATP raised eyebrows in June 2015 on revealing plans to switch 80% of its Ile-de-France (Paris and region) fleet of 4,500 buses, i.e. 3,600, over to electric plug-in by 2025 (to date there are around 20 on the streets).

Yet many doubt such a bold objective can realistically be achieved. Since an electric bus today costs around €500,000 (twice the price of a diesel), RATP’s operation will amount to some €2 billion!

“Yes it represents a major investment for us,” concedes Nathalie LeBoucher, director of strategy, innovation & development, RATP. “But don’t forget that the roll-out will be a gradual process, running up to 2025.”

Anne Hidalgo, mayor of Paris, wants to outlaw diesel vehicles from the French capital by 2017.

Exploring the electric avenue

In Sweden, Keolis Sverige, the country’s second largest bus operator, is actively involved in ElectriCity – a project whereby industry, researchers, and society are working together to develop, test, and demonstrate new, electricity-based solutions for the future.

The trial in Gothenburg, up and running since June 2015, involves Keolis running 10 buses, of which 3 fully electric and 7 electric hybrid, on a new route (Line 55) covering a distance of 10km.

Volvo Buses asked us if we wanted to join the initiative,” explains Magnus Akerhielm, managing director, Keolis Sverige. “And since we strongly believe electricity will be a part of the future, this demo is providing us with an ideal opportunity to find ideas and concepts around the electric bus.”

While the electric hybrids are powered by electricity for about 70% of Line 55, the 100% concept ElectriCity vehicle, based on the Volvo 7900, is optimised to run 10km (it can go for 20km if really necessary), with charging at the line ends taking around six minutes. Appealing figures, but what about those on the price tag?

Ulf Magnusson, senior vp, Europe business region, Volvo Buses, hints that a purchasing price of around €500,000 “wouldn’t be too far off the mark” (i.e. over twice the price of a diesel equivalent).

To lessen the blow, Jessica Sandström, senior vp city mobility, Volvo Buses, is quick to point out that this bus should cost between 5 and 10% less to operate, i.e. in terms of energy consumed, maintenance, and driver productivity.

Conclusion: while the ElectriCity demo is undoutedly showcasing an seductive solution to today’s environmental and fuel preoccupations, it still remains (for the time being) out of the financial reach of all but the most prosperous of cities.

But then again, surely someone or some entity has to create the momentum, get the ball rolling, get the volumes growing?

Volvo Buses is quite clear about its intentions in the field of sustainable transport. “We want to be the leader,” states Mr Magnusson. “And the cornerstone of hybrid, electric hybrid, and electric buses is the electric drive.”

A matter of biofuels

Produced directly or indirectly from organic material (biomass), one of the most widely used liquid biofuels for transport is ethanol.

For buses, the upsides of ethanol compared to diesel is that the vehicle efficiency is the same and local C02 emissions are reduced by up to 90%; the downsides are a lower energy content and higher maintenance vehicles.

Meanwhile biogas, a renewable gas (methane) formed naturally when organic materials are decomposed, is widely considered to be the cleanest alternative fuel available today: emissions in principle consist only of water and C02, and since the latter comes from biological materials it does not contribute to climate change.

Cities running token ethanol buses in their streets today include Oslo, Madrid, La Spezia (Italy), Nottingham and Bristol (U.K.). Yet Stockholm is home the world’s largest bus fleet driven by this type of propulsion.

Indeed for several years now, the fleets operating in central Stockholm, 400 vehicles in total, have only run on ethanol, with a further 25 powered by biogas. Importantly, the biogas used is locally produced, coming from sewage plants in the Stockholm area, which reduces the carbon footprint of its delivery.

Cleaning up the car

When it comes to the automobile, in the light of volatile oil prices, deteriorating city air quality (and related health problems), plus climate change, attitudes towards cleaner propulsion have shifted. The Volkswagen diesel emissions scandal in 2015 has no doubt proved further fuel for thought.

Mass-market introduction of plug-in electric cars (also referred to as ‘electric vehicles’ or EVs) began around 2010, with models now available including the BMW i3, Chevrolet Spark EV, Fiat 500e, Kia Soul EV, and Nissan Leaf. Indeed many of the major car constructors already have, or are working on a model.

Even Apple is rumored to be developing a pure EV under its so-called ‘project Titan’.

This new generation of vehicles is really helping drive adoption by tackling the barriers traditionally associated with the EV: namely limited driving range, long recharging times, and the lack of charging points.

The appeal of electric propulsion lies in the general perception of its ‘goodliness’– EVs reduce dependency on fossil fuels and generate no local emissions (so cleaner city air).

But let’s not forget that the global ‘cleanliness’ of the vehicle ultimately depends on how its electricity is produced, i.e. from coal, nuclear power, or other.

Two engines, one hybrid

Car drivers keen to clean up their act don’t have to think ‘either, or’. Plug-in Hybrid-Electric Vehicles (PHEVs) – powered by gasoline and using a battery and motor to improve efficiencyoffer many of the benefits of EVs while mitigating some of the drawbacks.

For instance, with their high-capacity, rechargeable batteries they can store sufficient electricity to significantly reduce their fossil fuel consumption under typical driving conditions. Indeed PHEVs use roughly 30 to 60% less fuel than conventional vehicles, meaning less CO2 emissions in the city.

Despite these highs, there some lows. Grey areas remain over recharging times and the scarcity of stations to plug in. PHEVs are high maintenance, too. And of course their environmental strength obviously increases if they are driven by electricity from ‘green’ sources such as solar, wind, or small-scale hydro-electricity.

Is hydrogen on track?

Despite emitting no greenhouse gases (GHG) from their tailpipe but just heat and water, hydrogen fuel cell vehicles (FCV) are few and far between on the roads, in the streets.

Indeed the only commercial production models currently available are Hyundai’s Tucson Fuel Cell, the ix35 Fuel Cell by Honda, and Toyota’s Mirai. A step in the right direction, certainly, yet the commercial future of this propulsion technology still remains uncertain.

‘Most Western automotive manufacturers are preparing fuel cell vehicles for sale but nothing is guaranteed, because […] the other option for zero pollution at point of use, the pure electricity battery or supercapacitor vehicle, is also improving rapidly and they will often go head to head in the marketplace.’

‘Fuel Cell Electric Vehicles 2015-2030: Land, Water, Air’ (IDTechEx)

Further hurdles to commercial deployment include question marks over the production and storage of the gas, the performance of the fuel cell technology itself, and the overall cost of the vehicles (up front and over life).

Furthermore, and crucially, there simply aren’t enough pumps around! Is there one in your street? If not, why would you buy this kind of car? As IDTechEx rightly points out ‘refuelling time is irrelevant if it takes ages to reach a refuelling station.’

Neverthess Toyota is hoping the Mirai’s purported 450km range and fuelling speed of around five minutes will enable it to compete seriously with the EV (range typically limited to 96 to 193km on a full charge, although a few models can go 321km).

And moves are being made to address the lack of pumps. In the U.K., industry leaders and Government have been making a concerted effort since 2015 to address this penury. The H2Mobility project seeks to build an infrastructure serving metropolitan areas and the major routes linking them, progressing to nationwide coverage by 2030 (to date, just 15 hydrogen fuel stations are currently dotted across the country, with only four fully accessible to the public at large).

Driving forces

The market for hydrogen cars has been typically driven by companies providing the gas and its infrastructure, as well as transport firms seeking to ‘green’ their business.

At the end of 2015, coinciding with the launch of ‘Hype’ – France’s first fleet of hydrogen-powered taxis –  gas multinational Air Liquide  installed the first hydrogen refuelling station in Paris centre, in partnership with electric taxi start-up STEP (Société du Taxi Electrique Parisien) and Hyundai.

‘While this first station is temporary, remaining in situ until the summer of 2016, a network of similar stations, primarily destined for filling the taxis, will be gradully deployed in the Paris region,’ says Air Liquide.

Currently running five ix35 Fuel Cell vehicles, by 2020 Hype plans to ramp its fleet up to several hundred. Ride fares, it says, should cost no more than a regular taxi.

The strengths of these H2 cabs, as championed by its partners, are fast charging – between three to five minutes to fill up – and greater autonomy than an electric equivalent – the ix35 Fuel Cell’s two reservoirs can store 5.63kg of hydrogen and withstand up to 700 bars of pressure, guaranteeing a range of some 500km.

How clean is clean?

While touted as an emissions-free vehicle, the global ‘cleanliness’ of the hydrogen car depends on how its gas has been produced: today, around 95% of the world’s supply is ‘natural’, i.e. derived from fossil fuels.

Aware of this room for improvement, Air Liquide has been making efforts for some years now. Through its label ‘Blue Hydrogen’, the company aims to decarbonise 50% of its production ‘destined for energy applications’ by 2020.In practice, this involves actions such as biogas reforming, using renewable energies via electrolysis of water, plus technologies for capturing and valuing the CO2 emitted during hydrogen production from natural gas.

Despite its imperfections, hydrogen has much merit. And let’s not forget the importance of reducing local emissions for reasons of well being.

According to the World Health Organization (WHO), air pollution is now the world’s largest, single, environmental health risk. And with more and more of the global population living in cities, emissions are having an ever greater negative effect – common pollutants that vehicles emit can cause, or aggravate, respiratory or cardiovascular diseases, cancer, and asthma.

Fuel for thought

European Union (EU) targets call for 10% of all transport fuel to be derived from renewable sources by 2020.

In order to diminish emissions from the transport sector, encouraging the use of collective modes as provided by public transport and shared mobility services, together with walking, and private cycling, while increasing the use of alternative fuels and propulsion in parallel sound like the right idea. Yet it’s easier said than done.

“Barriers to sustainable transport are mostly political, rather than technical”

Michael Replogle, chairman, SLoCaT Foundation

“Urban mobility is stuck in a rut. We are still using 100 year-old technology and systems, such as the combustion engine, to move around in today’s cities,” says Bertrand Piccard, the Swiss doctor, psychiatrist, explorer and aeronaut behind the Solar Impulse plane (together with partner André Borschberg).

“Indeed the objective of Solar Impulse [to circumnavigate the globe by solar power only] is to change attitudes towards the viability and potential of alternative propulsion technologies.”

‘The adventure showing clean technologies can change the world. If an airplane can fly day and night without fuel, everybody could use these same technologies on the ground to halve our world’s energy consumption, save natural resources and improve our quality of life.’

“The goal of explorers today is not about conquering territories, but quality of life on earth,” insists Mr Piccard, adding: “If governments had the courage to promote clean technologies on a massive scale, our society could simultaneously reduce its dependence on fossil fuels, create jobs, and stimulate sustainable growth.”

There are signs that fossil fuels are losing their appeal. Oil prices may fluctuate, yet R&D into clean propulsion technologies continues. But then again  petrol and diesel are cheaper than milk and beer in some countries.

The tipping point, it seems, will really only come when the price, rather than the planet, is right.




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