Materials, energy and water
The main materials used in Wärtsilä products are various metals: cast iron, alloy and structural steel, aluminium alloys and bronze. Recycled material content of these metals vary depending on the material and supplier in question. E.g. recycled material, such as end-of-life coins and bronze propellers, is used in the casting of new propellers. In 2010 the total material usage was 100,896 tons (129,320). The major material groups were various metals 69% (66), sand 21% (21) and various chemicals 8% (10).
Total energy consumption
The total energy consumption (in terajoules, TJ) includes the electricity, heat and fuels used in Wärtsilä companies in recent years. The fuels are used mainly in engine testing. The other purposes of use include heating, production and transportation.
Wärtsilä uses electricity in its manufacturing operations - for example, in machining components - and in service workshops and offices. Both the electrical and the heat energy generated during engine test runs can be utilised. Wärtsilä's aim is to use the electrical energy for its own purposes while also selling part of this electrical energy to a local power company. Due to the nature of engine test runs, the production of electricity and the company's electricity demand are not equivalent; this allows the surplus energy to be sold to a local power company.
Heating for factories and offices accounts for most of Wärtsilä's consumption of heat energy. In several factories the heat generated in engine test runs is used for heating. Some factories and offices are connected to a local district heating network, some have their own heating plant, and some use electricity for heating.
The water consumed by Wärtsilä can be divided into two categories: domestic use and cooling use. Domestic water is used mainly for sanitary purposes and by industrial equipment such as machine tools and washing machines. Some factories also use domestic water to produce moulds. Heat emissions into water systems arise from engine cooling and process cooling water. Wärtsilä companies use water from the local watercourse for their engine and process cooling needs. In such cases, the cooling water system is kept separate so that only heat is released into the natural water system. Wastewater is sewered and piped to the local wastewater treatment plant. If effluent is not suitable for sewage treatment, it is taken away for appropriate processing, for example to a special treatment plant for hazardous wastes.