Location: NO - Norway
This dataset represents the production of 1 kg of metallurgical-grade silicon (MG-silicon) with a purity of 99%. Silicon is used for the production of aluminium compounds (ca. 50%), silicones (plastics) (ca. 40%) and electronics (ca. 4%). Most of the MG-silicon is produced by carbothermic reduction. For the use in semiconductors further purification is necessary. About one million tonnes of MG-silicon with a purity of 98.5-99.5% was produced in the year 2000. The electricity use is the most important economic factors. The major producers are in Norway, the USA, South-Africa, Brazil, France and Australia.
This dataset is based on production in Norway (electricity supply is basically from hydropower), because most data are available for this country and it represents an important share of the total production. Most of the five production plants (Meraker, Bremanger, Fiskaa, Salten and Thamshavn) are in low-density populated areas and have a direct access to a harbour.
Reference(s):
Jungbluth N., Stucki M, and Frischknecht R. (2009) Photovoltaics. In Dones, R. (Ed.) et al., Sachbilanzen von Energiesystemen: Grundlagen für den ökologischen Vergleich von Energiesystemen und den Einbezug von Energiesystemen in Ökobilanzen für die Schweiz. ecoinvent report No. 6-XII, Swiss Centre for Life Cycle Inventories, Dübendorf, CH, 2009.
Undefined unit processes (UPRs) are the unlinked, multi-product activity datasets that form the basis for all of the system models available in the ecoinvent database. This is the way the datasets are obtained and entered into the database by the data providers. These activity datasets are useful for investigating the environmental impacts of a specific activity (gate-to-gate), without regard to its upstream or downstream impacts.