The power of less

Audi continues groundbreaking work with alternative energy sources to maximise future efficiencies.

The vision – CO2-neutral mobility. To realise it, Audi is working on green technologies and alternative energy sources. Natural gas, electricity and hydrogen offer specific advantages for different uses. 

3 January, 2017

There are different ways of gazing into the future. Yet to really shape it, you need concrete ideas, technologies and visions. Reiner Mangold, head of sustainable product development at Audi, sees the future in Audi tron. Audi tron stands for technologies designed to meet one of the biggest challenges facing the automotive industry: the efficient use of increasingly scarce resources. But Audi is not limiting itself to electric mobility. What matters more than the drive system for the future of both the automobile and our atmosphere is the energy source – it makes all the difference. Mangold: 

“If you drive an electric car in China and recharge it with fossil-based electricity, its environmental footprint is worse than that of a diesel.” It’s that simple, but it’s also that complicated. 

Taking an overall view, the most sustainable vehicles in the Audi range right now – irrespective of where they are being used – are the g-tron models. That’s particularly true when the gas is not fossil-based but comes from the four rings’ own e-gas plant in Werlte, Lower Saxony. The first of its kind in the world, the 6,000kW power-to-gas plant produces synthetic gas from renewable electricity, water and carbon dioxide. Since it produces oxygen and binds CO2, the cars its e-gas powers are virtually carbon-neutral. 

All-electric vehicles are ideal for city traffic because they do not produce any local emissions. However, due to limited storage capacities and a still underdeveloped battery-charging infrastructure, they are less suitable for longer distances. For customers who want to drive electric some of the time but also want to go long distances, Audi therefore offers plug-in hybrids like the Audi A3 Sportback e-tron and the Audi Q7 e-tron 3.0 TDI quattro. 

The next step on the road to CO2- neutral mobility will be clean liquid fuels, which likewise comply with the purity rules for Audi e-fuels: Just as with Audi e-gas, their production ties up exactly the same amount of CO2 as is emitted during operation of the car. A pilot plant in Dresden, Germany, has already been producing e-diesel for two years. 

Meanwhile, Audi together with a partner company in France is developing sulfur- and benzene-free e-gasoline and has teamed up with a US biotechnology firm in New Mexico to research the production of high-purity e-ethanol. Reiner Mangold is confident that “we’ll soon be able to supply e-fuels for all tron models and, in the long term, for the entire Audi fleet.” 

At the same time, Audi is working on getting the first Audi h-tron into showrooms. Although the power-to-gas plant in Werlte already produces e-hydrogen, too, the most critical issues surrounding hydrogen mobility have not yet been satisfactorily resolved.

Before that time comes, solutions complementing e-mobility continue to be needed. Reiner Mangold sees the answer in a balanced mix: “Our vision is to create sustainable mobility with affordable technology, intelligent upgrades, clean e-fuels, advanced technologies and above all systemic integration of these technologies in tomorrow’s renewable energy system.”

Audi g-tron: clean and economical 

In combination with Audi e-gas, Audi g-tron* is the order of the day for people wishing to reduce CO2 emissions and still drive economically. The Audi A5 Sportback g-tron adds an emotional design element to the notion of sustainability. The engines in the Audi g-tron models are based on TFSI units with specially adapted pistons and valves which can run on both cheap CNG (compressed natural gas) and, if required, also on standard fuel. Alongside the CNG tanks in the underbody, which take up hardly any luggage compartment space, there is also a fuel tank on board. There are now almost 1,000 CNG filling stations in Germany alone. The Audi A3 Sportback g-tron, for example, has a range of 400 kilometres in CNG mode. If Audi e-gas is used, the same model is practically CO2-neutral. By means of the Audi e-gas fuel card, Audi records how much CNG is consumed and ensures that exactly the same amount of CO2-neutral Audi e-gas is fed into Germany’s natural gas grid. Switching from CNG to petrol operation is automatic in all models and occurs unnoticeably as soon as the pressure in the CNG tank falls below 10 bar. The Audi A3 Sportback (81kW) is already available today with g-tron technology. In 2017, it will be joined on the market by the Audi A4 Avant g-tron and the Audi A5 Sportback g-tron. 

*These models are not available in Australia at time of writing

Audi e-tron: electrically efficient 

In plug-in hybrids such as the Audi Q7 e-tron 3.0 TDI quattro, propulsion is provided by combining an internal combustion engine with an electric motor. The latter draws its energy from a lithiumion battery. The Audi Q7 e-tron 3.0 TDI quattro with a system output of 275kW is the world’s first plug-in production model featuring a six-cylinder TDI and quattro drive. It accelerates from 0 to 100 km/h in 6.2 seconds but can also cover up to 56 kilometres in electric mode. In addition, the brand with the four rings offers the new Audi A3 Sportback e-tron, whose combination of 1.4 TFSI gasoline engine and electric motor brings a system output of 150 kW to the road. Sprinting from 0 to 100 km/h in 7.6 seconds and reaching a top speed of 222 km/h, it can travel up to 50 kilometres on one battery charge in pure electric mode. Hooked up to an industrial socket, both regain their full electric range after just 2.5 hours. At the same time, Audi is already working on a solution for charging future all-electric Audi models, and the Audi e-tron quattro concept provided a foretaste of it last year: Audi wireless charging. The energy is transferred via a floor charging plate connected to the electricity grid. Once the vehicle is positioned correctly over the plate, the battery in the Audi e-tron is charged instantly or on a timer without the need for a cable. 

Audi h-tron: power from the cell 

On one tank of fuel, the Audi h-tron quattro concept can travel up to 600 kilometres – leaving only a few drops of water in its wake. It’s made possible by a fuel cell fed with hydrogen. In the cell, the hydrogen is first broken down at the anode into protons and electrons. While the protons flow through a membrane to the cathode and react with oxygen in the air to form water vapour, the electrons supply electric current to drive two motors on the front and rear axles. The three hydrogen tanks are positioned beneath the passenger compartment and luggage compartment without taking away any interior space. They store enough hydrogen at a pressure of 700 bar for a range of up to 600 kilometres. According to the New European Driving Cycle, fuel consumption is roughly one kilogram of hydrogen per 100 kilometres. The Audi h-tron quattro concept is emission-free – not just locally but globally as well, provided the hydrogen in the tank is produced using green electricity. Here too, Audi e-gas technology from the world’s first industrial power-to-gas plant in Werlte, northern Germany, plays a decisive role. The plant already produces hydrogen from renewable electricity.