Novara Environmental Statement 2007 English MEMC-NO ...

Energy consumptionThe main source of energy for thesite in Novara is electricity suppliedby a trigeneration plant builtin 2006 and put into operationin the fi rst quarter of 2007. Saidplant, powered by natural gas(methane), meets all of the site’senergy requirements in terms ofelectricity and steam and 2/3 ofthe frigories required for the productionof cold water. The processesthat consume the highestamounts of electricity are: airconditioningsystems for the clean-rooms(about 30% of the totalamount), the polishing departmentand the epitaxy department(about 20% of the total amount).The site also uses steam for theair-conditioning system, alsosupplied from the trigenerationplant, and to a small degreemethane for drying mud derivingfrom waste purifi cation and dieselfor internal goods handling.Energy consumption values forthe single sources and the totalvalue are proposed in absoluteterms (toe:tonne of oil equiva-lent) and specifi c terms, in otherwords related to the annualamount of silicon produced formicroelectronics and solar photovoltaics(expressed in MSIE:million square inch equivalent).2007 saw a reduction in absoluteenergy consumption mainly causedby a fall in production, but alsothanks to the completion of plannedimprovement actions, mostimportantly activation of the trigenerationplant designed to meetthe sites energy requirements.Said plant, powered by methane,offers improved energy effi ciencyand at the same time a considerablereduction in carbon dioxideemissions to the atmosphere,as shown in the following graph.Another completed project thathas provided considerable energysavings (about 1 million kWhper year) is the optimisation of thecompressed air production plant.The downward trend seen in specificenergy consumption over thelast few years is proof of the company’scommitment to implementincreasingly more energy efficientproduction processes.Energy consumptionTOTAL CONSUMPTION (tep/year)Total energy consumption Steam Electrical energy Oil & MethanYear tep tep/MSIE tep tep tep2000 18482 106 3003 15269 2102001 18015 131 3185 14725 1052002 18409 107 3356 14950 1032003 19087 100 3417 15576 932004 19818 88 3432 16192 1942005 19208 90 3637 15435 1352006 19556 78 3493 15831 2322007 17474 77 3519 13762 193tep = equivalent tons of petroleum oilMSIE = million square inches equivalent20.00018.00016.00014.00012.00010.0008.0006.0004.0002.00002000 2001 2002 2003 2004 2005 2006 2007YEARSteamElettrical energyOil&MethanTotal energy consumptionSpecifi c consumption1401301201101009080706050SPECIFIC CONSUMPTION (tep/MSIE)15