Ships are a great passion for maritime specialist Tigges, who studied shipbuilding in Duisburg and later became interested in electrotechnical systems for large cargo and container ships. The combination of these two fields proved to be ideal, as Tigges explains: “It allows me to quickly assess whether new systems will meet the usual demands and conditions on a ship, for example.” Tigges spent the last few years at the small but highly specialized commercial shipping department of Siemens Industry in Hamburg, Industry Solutions, developing a system for optimizing the recovery of exhaust gas energy.

In Tigges’ system, hot exhaust gases from ship diesel engines, which are normally released into the atmosphere via the funnels, are used to drive turbo generators that can produce up to six megawatts of electric power for onboard equipment and ship propulsion. “This reduces fuel consumption by around 12 percent on average,” says Tigges. The waste heat recovery system was installed for the first time in the Danish container ship Gudrun Maersk in 2005. The use of exhaust gas to generate energy reduces not only costs for shipping companies but also environmental pollution, as most ships are powered by heavy fuel oil, which is relatively inexpensive but contains large amounts of pollutants. Although the very slow-running diesel engines in cargo ships use this fuel efficiently, they also release CO2, not to mention large amounts of nitrogen and sulfur oxides. The International Maritime Organization (IMO), which is the UN agency responsible for protecting the seas, has drawn up a series of regulations for reducing ship pollutant emissions that will go into effect in the next few years.

Pollution in port cities is another issue being addressed by the maritime engineers at Siemens. The company has, for example, installed a facility at the Port of Lübeck, Germany, that provides ships with electricity generated on land. This eliminates the need to operate diesel engines when the ships are docked, thus substantially reducing pollution in the city of Lübeck. Tigges has also come up with another solution to ensure an environmentally friendly supply of electricity to ships docked in harbors. A patent has been registered for this invention, which involves upgrading components that are needed for a ship’s operation in a manner that enables them to run on electricity generated at environmentally friendly land facilities when the ship is docked.

Tigges likes to occupy himself with ships in his free time as well – more specifically, with his own sailing yacht, which is docked in Kiel, Germany. He and his wife like to spend as much time as possible on the water, but his two almost fully grown children prefer to stay on land. “Sailing is a relaxing and contemplative hobby,” says Tigges, which means that he gets a lot of his ideas when he sails out to sea.