Kreiskother is executive chief engineer at PEM, the chair established at RWTH Aachen for production engineering of e-mobility components. PEM develops electric vehicles and components, as well as the manufacturing processes needed to produce them economically. Among its 80-plus collaborators are Porsche, Ford, Bosch and MAN. Deutsche Post DHL Group, Germanys largest delivery fleet operator, is another important partner.

Kreiskother compared several forecasts of electric powertrain usage, from studies by the International Energy Agency, McKinsey and PwC. While these analyses diverged a bit regarding the likely mix of pure electric vs. hybrid electric units, they all agreed that 2020 will be a tipping point, or corridor as Kreiskother put it, when global EV and HEV sales could top 6 million units.

Hitting this target will depend on finding the right balance of vehicle range and cost that makes e-mobility accessible to the masses, he said. Long range between charges is desirable; sticker shock is not. A 200 to 250 kilometer driving range can be implemented for a reasonable cost, Kreiskother insisted. Sure, the Tesla S can do 600 [km] between charges, but the cost for those added kilometers makes no sense.

PEM believes several e-mobility segments will emerge, each needing a customized powertrain architecture. Most will rely on the familiar components of the electrified powertrain (electric motor, lubricated transmission or gearbox, differential, battery and power electronics) or hybrid powertrains, which also include a lubricated gearbox and clutch. There are also direct-drive designs that need no gearbox, he observed, but the high cost for these is a major challenge.

Whatever the type, each powertrain can be tailored to the intended use, whether delivery van, city car, long-distance vehicle or super sportscar. This will be easy to do, said Kreiskother. You can build the optimal powertrain for the specific driving cycle intended, just by varying the motor-gearbox-software parameters.

As examples, he pointed to two vehicles developed at PEM. One is the StreetScooter Work, a local delivery van powered by a 20 kWh battery and created for Deutsche Post. Its range is 80 kilometers (about the length of a daily postal route) and top speed just 85 km per hour, but it carries a payload of 900 kilograms, nearly a ton. Compare that to the e.GO Life, a basic urban car costing 19,900 euros before options. The e.GOs similarly sized 24 kWh battery enables it to go 154 km between charges and 160 km/hr, while hauling 350 kilos of passengers and cargo. It will start series production at a new factory in Aachen Rothe Erde this summer and will ramp up to 15,000 units next year.

What both these vehicles and other EVs have in common, Kreiskother pointed out, is that electric motors are highly efficient, and need the transmission only for acceleration and high-speed operation. Compared to conventional vehicles, electric motors reduce the relevance of tribologically active systems in the powertrain. This makes it possible to both downsize and greatly simplify the transmission; in fact, only one or two speeds may be needed. But downsizing comes with its own set of problems, such as increased heat generation.

The electric motor likewise will get downsized as much as possible. That will require improved cooling, most likely with an oil, although water glycols also are being field-trialed. The cooling fluid can be applied through hollow channels along the rotor shaft, by completely flooding the motor, or possibly as oil droplets sprayed onto the rotor windings.

One advantage of using oil is that it makes a single cooling circuit possible, so the same fluid that cools the motor can lubricate and fight corrosion in the transmission and differential components. Operating temperatures of e-motors dont exceed 200 degrees C, so oil can be used here, Kreiskother pointed out, adding that the current trend in the automotive industry favors the use of oil to achieve compact and lightweight designs.

Also speaking at the colloquium, which was organized by the Technische Akademie Esslingen, was Lutz Lindemann, chief technology officer of Fuchs Petrolub in Mannheim, Germany. He concurred with Kreiskother that new fluid technologies are going to be needed with e-mobility, because electric cars have vastly different lubricant needs than internal combustion engines. The next 10 to 15 years are difficult to forecast because there is no clear roadmap for how fast e-mobility will develop, he cautioned, but we need to at least try.

E-mobility presents a mixed scenario, with Europe and Asia in the forefront of adopters, Lindemann said. Those 260,000 electric vehicles sold in the European Union in 2016 represented only a 1.4 percent share. Yet by 2028, his company estimates, the EU new-car market could include 30 percent battery electrics, an equal share of internal combustion engines, and 40 percent hybrids.

Fuchs also expects to see e-mobility surge in Asia-Pacific, spurred on by Chinas mandate that 10 percent of new cars sold be electric in 2019 and 12 percent in 2020 and beyond. By contrast, Lindemann said, e-mobility is down the drain now in the U.S, stalled by the ongoing review of Corporate Average Fuel Economy targets promulgated under the prior administration.

Despite those big numbers around electric cars, the world already has about 1 billion conventional vehicles in service. Changing over to e-vehicles will be a sporadic, decades-long process, Lindemann suggested. And the rosy projections-12 percent of new cars in China, and 30 percent in the EU-tend to obscure the reality that most vehicles will continue to roll off the assembly line with internal combustion engines. Theyll still consume engine oil, transmission and gear oils, axle lubricants and so on.

Pointing again to the example of China, he noted that annual vehicle production there is forecast to reach 38 million to 40 million units sometime around 2030. This output will include 16 million electric vehicles and another 24 million internal combustion engines. To put that into perspective, China produced 22 million ICE vehicles in 2016. So ICEs will not vanish from the landscape, Lindemann said, although their appetite for engine oils and transmission and gear oils will taper off due to longer-lived products and more efficient usage.

Volkswagen isnt giving up on internal combustion engines either, the companys Thomas Garbe told the colloquium. The automaker is, however, pivoting away from fossil fuels in order to achieve decarbonization. The aim, he said, is first to run vehicles on cleaner-burning compressed natural gas, then on bio-derived CNG. And future cars will burn a pure, totally carbon-neutral e-gas synthesized from water and CO2 using renewable energy sources like wind, water or solar, he explained.

CNG from natural gas already offers higher octane and lower particulate and CO2 emissions than gasoline and diesel, but VWs own goal is to be CO2 neutral, said Garbe, who is team leader for fuels at the companys powertrain division in Wolfsburg, Germany. In the long run, e-gas will mean operating without any fossil fuel component, he told the colloquium.

Thats not the case now, he conceded; most CNG powertrains run on natural gas from fossil sources. But natural gas is simply ethane, and ethane can be generated by biological means, such as from waste. Development of synthesized e-gas is also underway, and Audi has begun supplying it from an industrial-scale pilot project in northwest Germany.

Politics and energy supply are the key factors that will determine the framework for e-gas mobility, Garbe said. Another holdup is the limited number of CNG fueling stations, although thats changing. We started in 2006 to develop cars to run on CNG. Next we have to optimize our sales strategy, and next we need to expand the fueling network. Then, when its working, well expand the cars portfolio again.

Some countries are building CNG infrastructure at a rapid clip, Garbe added, and those are the key markets we have to concentrate on: Italy, Germany, Netherlands and Belgium. Each plans to at least double its CNG filling station network by 2020, and together the four countries will have almost 5,000 sites in place by then.

Italy is far ahead in this race, Garbe said, thanks to favorable politics and a long-term commitment. So now there are more than 1 million CNG vehicles in the fleet there.

Germany aims to better that, and have 2,000 fueling stations dotting the countryside by decades end. That will help foster the nations CNG fleet, which VW believes could reach 1 million units by 2025.

The other needed component of a CNG fueling network is adequate storage capacity for natural gas. Garbe estimated that Europes existing gas distribution network is worth about 500 billion euros, although its not well exploited because demand is seasonal and uneven. Pointing for example to Germany, he said, The policy here is to have 90 days worth of energy stockpiled for security. Households are a large part of this network, but houses here are well-insulated and they dont use gas year round. Why not tap into that surplus for vehicles?

The line-up of CNG-fueled vehicles from VW has grown to include more than a dozen cars, light trucks and vans. They range from the petite, 68-hp Eco up! to the 170-hp Audi A4 Avant G-Tron. Another model, the new 1.0-liter engine Polo, can drive for less than 1.3 euros per 100 km, and achieve a top speed of 184 km/hour, Garbe enthused.

CNG vehicle purchasing reasons include availability of the filling station network, having a good selection of vehicles to choose from, and widespread education and information. As each of these advances, Garbe summarized, we will have an attractive offer for the consumer.

Deutsche Post: OEM

PEM, the e-mobility chair at RWTH Aachen University, has commercialized several electric vehicles, from small to big. One of its top successes is a full-electric, 8-cubic-meter light utility van. It worked closely with Deutsche Post DHL Group on the vehicles design and manufacturing, and set up production at a former Talbot/Bombardier factory in Aachen-all in about one years time. Deutsche Post ended up liking the result so much that it bought the entire business, and renamed it StreetScooter GmbH. The German logistics companys fleet of 92,000 vehicles now includes 5,000 of the e-vans, with more to come.

As production scales up and a planned second factory opens, DP plans to sell the StreetScooter to other fleet operators. And this year, the company began working with Ford to make a larger version of the e-van. With a payload of 20 cubic meters, its based on a Ford Transit chassis and will be available for sale to other operators, too, the companies say. -Lisa Tocci