Electricity use in the Swedish carpentry industry

Because of its large magnitude, industrial electricity consumption deserves attention. Therefore the electricity demands of three carpentry factories in Sweden have been studied. The results show that major savings of electricity can be achieved and that opportunities exist to shift necessary activities so they occur during periods of lower unit-price tariffs. The owner or director of each factory is only rarely a specialist in energy issues and usually does not know how much can be accomplished in saving money in these ways. Nevertheless a short period (a few days) of monitoring, in each of the three factories studied, showed that it would be highly profitable to install larger capacitors for cutting the reactive power: the payback period for such a measure is about a year. Further measurements of the electricity demand revealed that one of the factories used, at maximum, only about one-third of its subscribed power, i.e. the predeclared maximum peak power that the subscriber thinks will be needed. Thus, changing the supply contract or distribution agreement could save at least 25% of the electricity costs each year, and this would be achieved without reducing the expenditure by a single kWh of energy. In addition, even a small carpentry factory has several systems that are energized by electricity, e.g. all the motors for the carpentry machines, the wood-chip transportation equipment and the wood-drying apparatus, and so many opportunities exist to achieve real energy savings.