SIEMENS

When the west wind rises and the North Sea begins to churn and send its heavy breakers crashing against the dunes of Jutland, thousands of windmills go into action on the Danish coast. Today, 20 % of Denmark’s electricity is produced by wind power, making it the world leader in this area, and this figure is set to rise to 50 % by 2025. Still, the good feeling about so much renewable energy is dampened by the fact that when the wind blows too strongly, the wind-turbine rotors generate more electricity than Denmark’s grid can handle. Up until now, Danish power utilities have had to send this surplus electricity to neighboring countries — and pay for doing so.
It is therefore not surprising that Denmark is a pioneer in the development of storage technologies to accommodate excess electricity, with researchers focusing mainly on the batteries used in electric vehicles. Current plans call for one out of ten cars in Denmark to run on electricity from wind power in ten years. Although this goal may seem ambitious, given that there are hardly any electric vehicles on European roads today, Denmark is moveing ahead rapidly with electric mobility through a broad range of projects — and Siemens is providing support as a development partner in two areas: connecting vehicles to the grid and automotive engineering.

Road to the Climate Summit. For example, together with Ruf, a German company that specializes in custom vehicles, Siemens will present three electrically-powered Dakara automobiles at the UN’s World Climate Change Conference in Copenhagen, Denmark, in December 2009. These vehicles are based on the Porsche Cayenne chassis and have an integrated charging system with which they can be charged from any power outlet that provides 230–400 V. A plug for this application has already been standardized. Charging times will depend mainly on what type of output the outlet offers. Developers expect to see an initial charging power of around 10 kW, and up to 43 kW over the medium term, which corresponds to a charging time of between 20 minutes and two hours. Charging will take place via an electrical connection under the fuel tank flap.
In Spring 2009 at the Geneva Motor Show in Switzerland, Ruf and Siemens presented a Porsche 997 Targa-styled model that had been converted into an electric car known as the eRuf Greenster (see Pictures of the Future, Spring 2009, "Electric Ecosystem"). This vehicle, which offers 270 kW of power and a top speed of 250 km/h, also boasts high torque and impressive acceleration right from the start. Whereas a combustion engine needs some time in order to fully develop its power, an electric motor delivers its full performance immediately.
The Greenster is a pioneering vehicle that demonstrates just how chic electromobility can be. Still, because the model was developed in only three months, its individual components were not all part of a new component approach but instead represent a combination of available standard components. "The successor Greenster II model, which is already being planned, will have optimally matched components," says Prof. Gernot Spiegelberg, head of the Electromobility Team at Siemens Corporate Technology (CT). Such components include a fast-charge unit and precisely tuned components for battery management, motor control, and charging electronics. The Greenster II will be completed by the end of 2010.

Standardized Charging. The Dakaras, for their part, will be charged at the UN conference with wind power and will be used in a shuttle service between the conference center and the airport. Each vehicle can accommodate four passengers and their luggage. The Dakara concept includes a "power pump" from Siemens that communicates with the vehicle’s electronics. This is one of the key challenges for electromobility — and not just in Denmark. After all, drivers will want to recharge their electric vehicles at any location — be it a garage, supermarket, or company parking lot. In a manner similar to cell phone invoicing, the electricity used will be billed by a provider. However, for such a system to work, it will be necessary to reliably identify the vehicle and exchange data between its onboard electronics and the charge pump. In a project with energy supplier RWE, Siemens will soon be installing 40 charging stations at locations in Germany, with 20 stations planned for Berlin. In addition, RWE is now staging a roadshow in Germany that features the Greenster. Siemens is participating in the tour, which also made a stop at the IAA International Motor Show in September 2009 in Frankfurt am Main.
Siemens is pursuing the development of electromobility through a comprehensive approach involving not only automotive engineering — as is the case with Greenster and the Dakara — but also systems for connecting vehicles to the power grid. Here, both the charging process and communications are being addressed. Spiegelberg refers to these two areas as "Inside Car" and "Outside Car." "We’ve put together a team that covers all facets of electromobility," he says. In addition to CT researchers, that team includes specialists from Siemens’ Energy and Industry Sectors, who are needed because future electromobility will be about more than just the vehicles themselves. The idea is that as electric vehicles enter the market, the power grid will have to be updated. It will, for example, be necessary to install systems that can accommodate the total electricity requirements of the individual vehicles in public areas such as inner-city parking garages and sports stadiums. Here, one distribution transformer complete with switchgear will be needed for every 50 vehicles. This means several dozen such transformers will have to be linked via medium-voltage switchgear. Having several thousand vehicles parked in one place will require major facilities, and these will have to be installed in basements or separate buildings. After all, if 10,000 vehicles simultaneously tap the grid for 20 kW each, the resulting required output will be 200 MW — which is what a medium power plant produces.

Batteries on Wheels. The energy specialists for "Inside Car" and "Outside Car" are currently participating in Denmark’s EDISON project, which stands for "Electric vehicles in a Distributed and Integrated market using Sustainable energy and Open Networks." EDISON, the world’s first and most extensive project of its kind, will bring a pool of vehicles to power outlets and connect them to the fluctuating power of the wind. The associated technology for vehicles and the grid will be developed and prepared for use over the next two years.
Practical testing will begin in 2011 on the Danish island of Bornholm in the Baltic Sea. There, test vehicles will be charged with wind power from the public grid. When demand in the grid rises — at breakfast time, for example — parked cars will feed electricity back into the network. The Danes are hoping that a fleet of thousands of vehicles will be able to offset fluctuations in the wind-power supply in the near future. Instead of having separate electricity storage units to buffer against the fluctuations, the cars and their batteries will provide additional storage capacity, which is why EDISON will focus on achieving a bidirectional flow of electricity from the grid into vehicles and back. The results could be significant. If, for instance, 200,000 vehicles, each rated at 40 kW, are connected to the grid, a total output of 8 GW would be available at short notice — more than Germany requires as a cushion against consumption peaks.
In addition to Siemens, the EDISON consortium includes the Technical University of Denmark (DTU) and its Risø-DTU research center, as well as Denmark’s Dong Energy and Østkraft power utilities, the Eurisco research and development center, and IBM. In the EDISON project, various working groups are responsible for developing all the technologies needed for electromobility. Here, Siemens is mainly responsible for fast-charge and battery replacement systems. "Siemens’ portfolio already contains many components that we are now adapting and reprogramming," says Sven Holthusen, who is responsible for the EDISON project at Siemens’ Energy Sector.