Volkswagen and photovoltaics

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1 Volkswagen and photovoltaics Taking responsibility. Our commitment to renewable energies.

2 Energy from sunlight! At the Volkswagen conference entitled»photovoltaics how to harness the sun«, held on 2o June 2oo8, energy experts revealed the promising potential of solar technology. The efficiency of today s commercially available photovoltaic modules, i.e. the percentage of energy gained from solar radiation, amounts to 15 percent. By contrast, researchers are already achieving efficiency rates of 35 to 5o percent with new technologies. And the more sophisticated the technology, the more efficient the sun becomes as a»fuel«. Even today, a photovoltaics system on a garage roof with a surface area of 15 square metres using current technology would be sufficient to recharge an electric car. So the scene is set for the forthcoming generation of electric-powered vehicles to be driven by the power of the sun. In Germany, with today s photovoltaic technology, 3o percent of the roof surfaces facing south would alone suffice to supply all of the country s 6o million cars with electricity.

3 Volkswagen and sustainable mobility As part of its fuel and powertrain strategy Volkswagen researches and develops efficient technologies, innovative products and concepts with the aim of achieving mobility that will be completely emission-free in the long term. The vision is of sustainable mobility that is in harmony with the environment and based solely on renewable energy sources. Biofuels are the most readily available. SunFuel derived from biomass, for instance, can already replace 1o to 2o percent of today s fuel requirements. Solar energy offers far greater potential for power production. Every hour the earth receives from the sun enough energy through sunlight to meet the electricity needs of the entire world for one year. Photovoltaics, the direct conversion of solar energy into electricity, is a technology aimed at exploiting this energy. Electric vehicles can utilise this sustainably generated power. With a range of 5o to 1oo km they would already be able to cover around 5o percent of all car journeys. Capable of around 4oo km, fuel cell vehicles, which use green hydrogen as an energy source, could reduce these range limitations.

4 Mobility in the future driving on electricity But how can the sun s energy be utilised? With the aid of solar modules, the sun s rays are converted directly into electrical power. This can then charge a local battery system or be fed into the main power grid. A further option is presented by electrolytic processes, which are used to produce hydrogen from renewably generated energy, which in turn can be used in fuel cell vehicles. Solar module Electrolysis Solar power Hydrogen Grid Hydrogen storage tank Hydrogen filling station Power from the socket Vehicle with fuel cell Purely electric drive

5 »Refuelling«is carried out conveniently at home via the mains or en route at the hydrogen filling station. Volkswagen s vision is that all future fuel cell cars or vehicles powered purely by electricity - will be able to complete everyday journeys with renewably generated energy from the sun, wind or water without any kind of restriction. Today the»twindrive«concept demonstrates what mobility might look like in the future. The plug-in hybrid drive is a combination of electric motor, combustion engine and battery system. It can run on electricity alone for short distances, and can also cover longer stretches thanks to its efficient hybrid drive. Energy is stored using state-of-the-art battery technology, which enables a purely electric-powered distance of around 5o km. In this respect, electric vehicles have one great advantage. They have the potential to store off-peak electricity and therefore to also buffer fluctuations in the grid. The vehicle is plugged into the mains at night and stores more electricity than it requires. In the morning, when large quantities of electricity are required, the stored surplus power can then be retrieved. Based on electric vehicles with a small discharge capacity of

6 just 1 kilowatt having a 5o percent share of the market, it would be possible to temporarily buffer 25 percent of the 225 gigawatts produced by Germany s power stations. Yet the crucial aspect in the success of photovoltaics for vehicle mobility remains the development of particularly long-life and cost-effective storage technologies. Volkswagen expects the costs of future battery systems to amount to only a quarter of today s costs. We therefore anticipate that the electrification of mobility will make a significant contribution towards sustainable mobility. At night In the morning

7 Photovoltaics plants at the Volkswagen factories In addition to the long-term development of electric vehicles, Volkswagen is already focusing on solar energy. Photovoltaics plants have already been set up at the Volkswagen factories in Emden and Wolfsburg, with a module surface area of 45,5oo square metres in total. Both plants together produce around 3.2 gigawatt-hours per year. This reduces annual CO2 emissions by 1,913 tonnes. To put this in perspective: photovoltaic modules covering half of the roof on a detached house would occupy an area of 6o square metres on average. Photovoltaics plant at Volkswagen factory in Wolfsburg

8 Volkswagen Aktiengesellschaft Fuel Cell and Fuel Research Dr. Frank Seyfried Brieffach 011/11720 D Wolfsburg Article no.: Z