There are currently around 16,000 registered vessels in the world with output above 10 MW of power. The entire global commercial shipping fleet is considered to account for between 4-5% of global carbon emissions.

We expect major environmental gains from this. Just Wallenius’ own vessels consume about 200,000-250,000 tons of bunker fuel a year. A fuel saving of between four and six per cent means that we cut emissions of carbon dioxide with about 37,000 tons a year and sulphur dioxide with some 150 tons a year.

The opportunities that Opcon Powerbox offers for utilizing waste heat and reducing fuel consumption onboard our ships are among the most interesting we have seen in this field. A fuel saving of between four and six per cent is considerable in this context. In future we see opportunities to use this technology and make savings of up to ten per cent. We aim to install Opcon Powerbox on all of our new vessels and on most of our existing ones in future. We want to be among the leaders in the shipping sector in reducing energy consumption and cutting emissions

—Per Croner, CEO of Wallenius Marine AB

An Opcon Powerbox during delivery to Munksjö Aspa Bruk, Sweden, in June 2009. Click to enlarge.

The Opcon Powerbox is an ORC implementation. Waste heat is used by a heat exchanger to vaporize a working fluid with a boiling point lower than water (thereby enabling the exploitation of low grade waste heat). The gas expands over an expander, which drives a generator to produce electricity. The fluid is then cooled, and a pump increases its pressure to 30 bar, and circulates it back through the first heat exchanger.

The theoretical level of efficiency is controlled by the temperature difference between hot and cold media. A key element in the Opcon Powerbox is the SRM turbine, developed by Opcon’s Svenska Rotor Maskiner, SRM.

Wallenius will pay for the installation costs and pay for supplied electricity during the test period. The aim is to complete an installation by the autumn of 2011 at the latest either on a new vessel or on an existing one.

Wallenius Marine has responsibility for crewing, operation, technical and environmental development of the Wallenius fleet and for EUKOR Car Carriers in their program of new construction. Through subsidiaries and together with partners, Wallenius controls more than 150 vessels.