Energy audit of a large company : Data collection, energy analysis and proposals of energy efficiency

The EU directives of energy efficiency and transparency of sustainablework have recently been implemented in Swedish law. This requires largecompanies to report audits of their energy use and how they work withsustainability. Due to the recent requirements, many companies do not havea systematic method to collect and report the data needed. In this projectsuch a company in construction and residential development - VeidekkeSverige - has been examined and evaluated. The aim of the project has beento systemize the collection and compilation of data from the energy use ofVeidekke Sverige and perform an energy audit and report their greenhousegas emissions. The energy audit involves systematically mapping energyusage and making proposals for cost-effective measures to decrease energyuse. This has been made at a general level for the whole company andstudied in detail at one of the affiliated companies - Veidekke Prefab.The routine for the collection of energy data developed in this projectwas made with standardized surveys, adapted to the type of data requestedin any special case, from a variety of internal units at the company andexternal suppliers. The compilation of the surveys has been programmed inExcel. Although the routine for the collection and compilation of energydata has been standardized from previous implementations, unique manualchanges to the compilation file is still required for an upcoming year. Arecommendation is therefore to implement the developed routine at adigital platform, where surveys can be filled in online and then managedand compiled automatically at the platform. The energy survey of VeidekkeSweden shows that energy consumption in 2017 was about 50 GWh, of whichfuel accounts for 37%, electricity for 33% and gasoline for 25%. Thus,measures of energy efficiency should be done in the use of these threesources. The detailed energy audit of Veidekke Prefab shows that thecompany has a high power consumption of which half derives from theproduction, although, focus of the energy audit has been on ventilationand heating. The plant has two buildings for drying that are heated withdirectacting electric boilers which are recommended to be replaced by airheat pumps. In addition, the ventilation unit for the large buildingshould be replaced by a more modern unit with rotary heat recovery toreduce demand of district heating with about 20 %. Another feasiblemeasure is to replace the lighting to LED units, which would reduce energyconsumption by 6 %