CO2-neutral in the future – The Audi technologies of tomorrow

With regard to the mobility of the future, customer requirements have evolved in very different ways. Besides the individual life situation, societal and legal parameters and the local availability of resources play key roles, and these differ dramatically from market to market.

Audi is developing a broad portfolio of technologies, drive systems and energy sources for the new mobility with the aim of offering the right concept at the right time for each market and each customer. This applies in particular to the rapidly growing megacities in the emerging nations. The Audi Urban Future Initiative, an interdisciplinary forum for experts that was established two years ago, is exploring the numerous issues encompassed by this topic.

Audi is providing a solid foundation for the future of mobility. The system modules are called e-tron for electric driving, ultra for intelligent lightweight construction and connect for the seamless networking of the car, in particular with its surroundings. This foundation is the basis for technological development that will include a large number of evolutionary, strategically coordinated steps.

Audi is striving to further expand its leadership role in TDI and TFSI engines, as the combustion engine will continue to be an exceptionally important part of the automobile for many years to come. At the same time, the engineers are working to electrify the drivetrain, i.e., on hybrid and electric cars that will have very different characteristics. Audi aims to become the leading premium manufacturer of electric vehicles by 2020, at which time hybrid and electric cars will be normal models with combined annual volumes projected to be in the six-figure range.

The vehicles that Audi is developing today for the mobility of tomorrow make it possible to drive with zero local emissions. These are electric cars such as the R8 e-tron and the A1 e-tron with range extender, which is currently undergoing fleet trials in Munich, or plug-in hybrids such as the Audi A3 e-tron concept. This initiative will provide a glimpse of the technologies that will begin volume production in 2014. But Audi’s plans go much further. The objective is holistic, CO2-neutral mobility. The company’s strategy here includes both the use of renewable electricity for its e-tron models and new energy sources such as hydrogen and e-gas.

The vision of holistic, CO2-neutral mobility goes by the name Audi balanced mobility. The first major step toward achieving this vision is the Audi e-gas project, as part of which Audi is the first carmaker worldwide to develop an entire chain of sustainable energy sources. Their end products are clean electricity, hydrogen and synthetic e-gas. Audi uses its own wind turbines to produce renewable electricity which will power future e-tron models. The hydrogen generated through electrolysis is suitable for use in fuel cell vehicles, and the e-gas produced through methanation makes climate-friendly long-distance mobility possible for cars with combustion engines.

The new technologies and the vehicles that Audi is developing for the mobility of the future will convey the strengths of the brand without compromises. Sustainability on the one hand, top quality and emotional driving enjoyment on the other: for Audi no contradiction, but rather the primary objective for the future of mobility.

The world is changing at a rapid pace, and protection of the climate is becoming increasingly important. Audi takes its responsibility for the environment and resources very seriously. Under the name of Audi balanced mobility, the brand is striving to achieve a major objective – CO2-neutral mobility. The brand will also further expand its leadership role in TFSI and TDI engines and continue to improve their efficiency even further, while at the same time the engineers are working on the energy sources of tomorrow and the electrification of the drivetrain.
Combustion engines

Combustion engines – the TFSI and the TDI – will remain the most important sources of tractive power in the automobile for the foreseeable future, and Audi is making them more efficient by leaps and bounds. More than 100 Audi model variants already have CO2 emissions below 140 grams per kilometer
(225.31 g/mile), with 32 variants below the 120-gram mark (193.12 g/mile). Audi wants to reduce the consumption of gasoline and diesel engines by as much as 15 percent over the next ten years.

TFSI engines

Audi has made great progress with gasoline engines, in particular, in recent years. Direct injection is standard in all engines, and almost all of them are turbocharged or supercharged. The downsizing principle – the substitution of forced induction for displacement – reduces fuel consumption and boosts performance.

The forced-induction TFSI engines from Audi harmonize perfectly with longer gear ratios while delivering uncompromising dynamics. The new 1.8 TFSI in the A4, for example, produces 125 kW (170 hp) and 320 Nm (236.02 lb-ft) of torque for sporty performance.

However, it consumes just 5.7 liters of fuel per 100 km (41.27 US mpg) on average – a CO2 equivalent of just 134 grams per km (215.65 g/mile).

Audi continues to drive development intensively in this area. Among the technologies in the Audi modular efficiency platform are the reduction of internal friction, regulated oil pumps, the start-stop system and innovative thermal management. The latest breakthrough is the cylinder on demand (COD) system. With the new 4.0 TFSI, four of the eight cylinders are deactivated temporarily at low load; with the new 1.4 TFSI with 103 kW (140 hp), two of the four cylinders are deactivated.

TDI engines

The TDI engine, a groundbreaking Audi innovation, is an extremely successful efficiency technology. Since its debut in the Audi 100 in 1989, the electronically controlled turbodiesel with direct injection has experienced a more than 100 percent increase in power and a 70 percent increase in torque relative to displacement. Its emissions have been reduced by 95 percent over the same period.

Audi has made great strides with respect to fuel consumption in recent years. In 2001, an Audi A8 2.5 TDI produced 132 kW (180 hp) and consumed 9.0 liters of diesel fuel per 100 km (26.13 US mpg). The 3.0 TDI in the current version of the luxury sedan produces 150 kW (204 hp) and consumes just 6.0 liters
(39.20 US mpg).

Audi is working hard to reduce fuel consumption even further, including for the four-cylinder TDI engines. At the same time, clean diesel technology drastically reduces NOx emissions for even cleaner exhaust.

In the future, each new Audi model will continue to be lighter – in some cases much lighter – than its predecessor. The development engineers will intelligently combine new materials, including carbon fiber-reinforced polymer (CFRP), in the bodies. At Audi, lightweight construction means the flexible use of various materials, always with the aim of using the least possible amount of the right material in the right place. In the intelligent composite construction, the selection and use of materials and their influence on the overall energy balance plays a crucial role. At Audi, an intelligent mix of different materials always also takes into account the effects on the environment and resources.

The holistic strategy Audi is pursuing with respect to electric mobility is incorporated into the evolving overall societal context. Customer expectations for the brand’s vehicles will vary greatly from market to market around the world depending on the individual life situation, societal and legal parameters and the local availability of resources.

The proper strategy is not to bring new vehicles into production as quickly as possible, but to perfectly satisfy customer demands.

Audi is developing uncompromising, holistic concepts for electric mobility that offer maximum benefits with innovative ideas and sporty, progressive and sophisticated cars that convey all the qualities of the brand without compromise. Perfection, fascination and emotion will also determine the character of an electrically powered Audi.

Audi considers the electric drive as one of the most important innovation drivers for the future and will gradually make it an integral component of its range. In a few years, the abbreviation e-tron will be as matter-of-course as the terms TDI, TFSI, ASF, ultra or quattro are today. Electric mobility will develop into a major pillar of the company and a testament to its future competence. Audi is striving to be the leading premium manufacturer of electric vehicles in 2020.

In electric mobility, Audi distinguishes between two major groups of vehicles. The first group is formed by the models with full hybrid technology, which can cover distances of several kilometers solely on electric power from their compact lithium-ion high-performance batteries. All other concepts use high-energy batteries for longer distances. These are plug-in hybrids, range extender vehicles and purely electric cars, which at Audi are grouped under the term e-tron.

A purely electric car will only be suitable in the medium term for distances up to roughly 200 km (124 miles), as a city or a second vehicle. A range extender – a small combustion engine that recharges the battery – already makes intermediate distances possible. Long distances of 500 km (310 miles) and more will be the domain of hybrid drives. These are true all-around performers, particularly in plug-in configuration, because in addition to their long range they can also drive for longer distances in cities with zero local emissions, which is a prerequisite for use in the zero-emissions zones expected in the future. Audi will bring its first plug-in hybrids to market in 2014.

In 1997, Audi advanced to become the first European carmaker to build a limited edition of a hybrid vehicle – the Audi duo based on the A4 Avant. The drive was provided by a 1.9-liter TDI developing 66 kW (90 hp) and an electric motor developing 21 kW, powered by a lead gel battery in the rear. Both units drove the front wheels.

Like the two concept vehicles preceding it, the production duo already followed the plug-in concept – its battery could be charged from a socket. The electric motor could also recover energy during braking. The duo reached 80 km/h
(49.71 mph) in electric mode and a maximum of 170 km/h (105.63 mph) with TDI power.

The first production hybrid model from Audi in the new century, the Q5 hybrid quattro, was launched in November 2011. The performance SUV is the first full hybrid in its segment with modern lithium-ion batteries. A parallel hybrid, it combines the performance of a six-cylinder unit with the fuel economy of a four-cylinder version.

Power is provided by a 2.0 TFSI with 155 kW (211 hp) and an electric motor with up to 40 kW and 210 Nm (154.89 lb-ft) of torque. System output is 180 kW (245 hp). The Audi Q5 hybrid reaches 100 km/h (62.14 mph) in 7.1 seconds from a standing start and has a top speed of 225 km/h (139.81 mph). At a constant speed of 60 km/h (37.28 mph), it has a purely electric range of up to three kilometers (1.86 miles), and its top speed of 100 km/h (62.14 mph) in electric mode also sets standards. Fuel consumption is just 6.9 liters per 100 kilometers (34.09 US mpg) on average. This equates to CO2 emissions of 159 grams per kilometer (255.89 g/mile).

An extensively modified eight-speed tiptronic serves the power transmission, without the aid of a torque converter. Instead there is the electric motor, which is combined with a multi-plate clutch. It connects and disconnects the electric motor and the TFSI. Electric energy is stored in a lithium-ion battery system weighing a mere 36.7 kg (80.91 lb). The battery provides 1.3 kWh of nominal energy and

39 kW of power. A sophisticated, two-speed air cooling system keeps it within the appropriate temperature window.

Over the next few months, the Audi A6 hybrid and the A8 hybrid will be hitting the streets. They use the same parallel hybrid concept as the performance SUV, except that the power is delivered to the front wheels. The two large sedans likewise produce 180 kW (245 hp) of system power, and their fuel consumption figures are well below 7.0 liters per 100 kilometers (33.60 US mpg). With these two models, Audi becomes the first premium manufacturer to offer full hybrids with lithium-ion technology in B, C and D segments simultaneously.

The Audi A3 e-tron concept is designed as an efficient, parallel plug-in hybrid. Its 1.4 TFSI engine produces 155 kW (211 hp), the electric motor 20 kW. Both units drive the front wheels. With its capacity of 12 kWh, the lithium-ion battery provides enough energy for a range of roughly 50 kilometers (31 miles). The Audi A3 will go into production as a plug-in hybrid in 2014, with the Q7 and A4 to follow a short time later.

The parallel layout of the drive components also provides for high efficiency in the plug-in hybrids. Splitting up the power of the combustion engine and the additional electric drive unit between the axles is an interesting alternative, however.

This is the approach taken by the e-tron quattro concept based on the Audi A5. In this case, the 2.0 TFSI engine mounted in the front of the car is augmented by two powerful electric motors, one mounted at the front axle and the other at the rear axle.

The dynamic Audi e-tron Spyder is also a plug-in hybrid, but it is based on a different concept. Its primary powerplant is a three-liter TDI engine producing

221 kW (300 hp). It is mounted behind the occupant cell and drives the rear wheels. Two electric motors producing a combined 64 kW drive the front wheels.

The LMP1 prototype R18 e-tron quattro for the 24 Hours of Le Mans is similarly configured. A mid-mounted 3.7-liter V6 TDI delivers a good 275 kW (510 hp) to the rear wheels. The front wheels can be temporarily driven by 75 kW of electric power per wheel. The energy, which is recovered during braking, is provided by a fly-wheel storage system.

The compact Audi A1 e-tron, on the other hand, is a specialist for the urban jungle and is equipped with an additional range extender. Its electric motor drives the front wheels with 75 kW of peak power. Range is roughly 50 kilometers (31 miles) in electric mode. A rotary engine in the rear, which currently displaces 254 cc and produces 15 kW (20 hp) makes long-distance trips possible by recharging the 12 kWh battery.

The first A1 e-tron models are currently undergoing fleet trials in Munich. Audi hopes to gain valuable insights about the technology and the usage behavior of the customers. The compact vehicle is virtually emissions-free, both locally and globally. It is being powered during the fleet trial with renewable electricity, which Audi considers an important element of sustainable electric mobility.

On the opposite end of the spectrum from the A1 e-tron is the Audi R8 e-tron. It draws its 230 kW solely from the powerful electric motors and the large lithium-ion battery, which stores 53 kWh of energy.

The high-performance sports car, which is packed full of new technical solutions, will be the first e-tron model to hit the streets when Audi launches it as a limited production model toward the end of this year. It will demonstrate how dynamic and dramatic an electric car from Audi can be.

The Audi A2 concept technology study – the star of the 2011 International Motor Show (IAA) in Frankfurt – is another purely electric car. Based on a classic, four-seat space concept, it combines e-tron technology with ultra lightweight construction and the new ideas of Audi connect. The vehicle can be charged inductively using the Audi wireless charging system, making the charging process even easier for the customer.

The concept vehicle already uses many technical components from the new hybrid models. However, fuel cell technology is not expected to be used in production vehicles in the medium term, as the cost-intensive development of the supply infrastructure for hydrogen remains an unsolved challenge for the time being.

In the e-tron models, the new Audi connect functions and services will enable drivers to handle energy management and route planning on their smartphones. Audi wireless charging technology uses inductive power transmission to conveniently charge the traction battery.

Audi already offers numerous features of networked mobility with Audi connect, from navigation with Google Earth or Google Street View images to assistance systems that bring drivers to their destinations relaxed and accident-free. The networking of the car with the driver, other vehicles, the infrastructure and the surroundings plays a major role in what is happening on the road. It also enables new mobility concepts that can optimize the flow of traffic, such as by communicating with traffic signals.

One example of the broad reach of Audi connect is piloted parking, a technology with which Audi cars can automatically maneuver into and out of parking spaces in above-ground and underground parking garages. The driver simply leaves the car at the entrance and picks it up there later – the car takes care of the rest.

The parking garage’s central computer monitors the vehicle’s movements by radar and guides it via WLAN to the nearest available parking space. For its part, the car monitors its surroundings by means of 12 ultrasonic sensors and four video cameras. In a future vision of piloted parking, it could be possible to automatically recharge or refuel the cars in the parking garage.

One answer from Audi is the Audi Urban Future Initiative. Launched two years ago, this interdisciplinary forum networks architects, sociologists, urban planners and trend researchers. The experts analyze the future of the cities with an eye toward individual mobility. The insights and ideas that emerge should be comprehensive in nature and address potential technical solutions as well as societal, ecological and aesthetic considerations.

The initiative is the umbrella for four formats: the Award, which is Germany’s most lucrative prize for architecture; the Summit, which is a symposium for the networking of knowledge; Research, which includes a variety of research projects; and the Insight Team, which interfaces between internal knowledge and external expertise. In this team, six Audi employees from Design, Communications, Technical Development, and Brand and Corporate Strategy take up the ideas and translate them for the company.

With a focus on “Which energies and forces will change the city of the future?” as a central question, the first Audi Urban Future Summit was held prior to the

2011 International Motor Show (IAA) in Frankfurt. Audi presented the Audi Urban Future Award in 2010 for the first time ever; it comes with a cash prize of

100,000 euros.

This competition will be held in 2012 for the second time; this year’s theme is “Transitions.” The six architectural offices invited to participate – CRIT (Mumbai), Höweler & Yoon Architecture (Boston/Washington), Junya Ishigami + Associates (Tokyo), NODE Architecture & Urbanism (Pearl River Delta), Superpool (Istanbul) and Urban Think Tank (São Paulo) – have been tasked with developing visions for the urban mobility of the future that, while anchored in the local context, are also transferable to the global level.

All six offices will develop concepts for the metropolitan regions in which they are based. An international panel of judges will select the 2012 award recipient in Istanbul in October.

“Ecology and economy in harmony – that is the future’s greatest challenge. To meet this challenge, we must bring all aspects of mobility into balance – with people, with people’s new values and with the environment,” says Rupert Stadler, Chairman of the Board of Management of AUDI AG. A central theme of the Audi balanced mobility project are the energy sources. As part of the Audi e-gas project, the brand is establishing an entire chain of sustainable, renewable energy sources – electricity, hydrogen and the synthesized gas Audi e-gas.

Audi is taking a number of different approaches to the field of alternative fuels. The brand already offers the A4 2.0 TFSI flexible fuel that runs on 85 percent bioethanol (E 85). It boasts an outstanding environmental balance if you do not simply look at the emissions leaving the exhaust system, but instead take the well-to-wheel view, which extends from the source of the fuel to the motive energy at the wheel.

There are numerous other environmental activities besides the e-gas project. Audi runs its own environmental foundation, which has an endowment of five million euros, and has planted forests in the vicinity of its sites in order to research CO2 conversion in trees in collaboration with its partners. The company is also an associate partner in the international consortium Desertec Industrial Initiative, which wants to produce solar power in the deserts of northern Africa and the Middle East.

Audi views each individual work step at the company in a wider context. The engineers already have an eye on ecology during the development of the vehicles. This applies not just for the individual parts and their assembly, but also for the efficiency of the manufacturing processes, the supply of power to the plants, the water circuits in the factories and the logistics processes.

The photovoltaic systems generating electricity on many of the factory roofs conserve resources just like the highly efficient trigeneration (power, heat, refrigeration) plant at the Ingolstadt site. The trains carrying cars to the North Sea loading port of Emden are powered by green electricity. By 2020, Audi wants to achieve a 30 percent reduction in overall site- and company-related specific CO2 emissions versus 1990 levels.

Audi e-gas project

The first major element of Audi balanced mobility is the Audi e-gas project, which is now moving into the practice phase following three years of intensive research. With this project, Audi is the world’s first premium automobile manufacturer to develop an entire chain of sustainable energy carriers. Their end products are clean electricity, hydrogen and synthetic e-gas. Audi uses its own wind turbines to produce renewable electricity which will power future e-tron models. The hydrogen generated through electrolysis is suitable for use in fuel cell vehicles, and the e-gas produced through methanation makes climate-friendly long-distance mobility possible for cars with combustion engines.

As the first step, Audi and a regional energy utility are financing four wind turbines in an offshore wind farm in the North Sea. With a capacity of 3.6 MW each, they are expected to together generate some 53 GWh of electricity for the public grid – enough to meet the demand of a mid-size city.

One of Audi’s objectives is to use green electricity to produce its electrically powered e-tron models with green electricity and to provide sufficient green electricity equivalents to run them. For example, a portion of the wind power from the four wind turbines could be used to produce 1,000 Audi A1 e-tron models and operate them for 10,000 km (6,210 miles) per year, while an additional 20 GWh of the sustainable wind power would be available to the public.

Furthermore, surplus wind power is used to supply a facility in the German town of Werlte, near Emsland, that produces hydrogen by means of electrolysis. The hydrogen could be used directly in the future as fuel for fuel cell vehicles such as the Audi Q5 HFC technology platform. Due to the lack of a supply infrastructure, it will not be used directly during the first phase of the project, however, but instead placed in a storage tank and later used in the world’s first industrial-scale methanation plant. This is connected to a refuse biogas plant, from which it draws the concentrated CO2 required for methanation and which would otherwise pollute the atmosphere.

The end product is Audi e-gas. This energy-rich fuel is chemically identical to fossil methane, the primary component of natural gas, and is thus extremely well-suited as a fuel for combustion engines. Beginning in 2013, the plant in Werlte will produce roughly 1,000 metric tons of methane a year, binding 2,800 metric tons of CO2.

1,500 specially modified A3 TCNG models can each drive 15,000 kilometers (9,320 miles) per year CO2-neutrally on renewably generated e-gas, for example.

The German energy industry could also benefit in the medium term from the concept of the Audi e-gas project, as it provides an answer to the unsolved question of how to store green power efficiently and independently of location. When the sea breeze is strong, excess electricity can be converted to e-gas and stored in the public gas network, which with a capacity of 217 terawatt hours is the largest existing energy storage system in Germany. The energy can be returned from the gas network to the electrical grid at any time as desired.

The potential of electricity-gas cogeneration to store large amounts of wind or even solar energy can provide powerful stimuli for the expansion of renewable energies. The Audi e-gas project can be applied easily to all countries with existing natural gas networks.

Audi A3 1.4 TCNG

The Audi A3 1.4 TCNG exemplifies the new combustion engines that can use sustainably produced fuel. The compact model is a quick, all-around car. It will be launched in 2013 and will become available at the same time as Audi e-gas. Its forced induction, 1.4-liter gasoline engine produces 81 kW (110 hp).