Energy saving in case of intermittent production by retrofitting service plants systems through inverter technology: a feasibility study

Many production machines have high energy consumption due to the large number of electrical motors used to rotate equipment, such as tools, fans and pumps. Moreover, in different industrial sectors production is not continuous but intermittent, where working times alternate with idle times. During idle times continuous switch off is not always possible due to technical limitations, and if it is possible, it can cause higher energy consumption due to peak current at the start-up of the electrical motors. The purpose of this paper is to introduce the possibility of managing intermittent production using inverter technology. The inverter provides power control by managing the frequency and voltage of the power supplied to the alternating current motors. The study analyses the potential energy consumption reduction as a function of the production parameters (number of daily stops, average working time, etc.) and develops a feasibility analysis, its related investment cost and its potential energy consumption reduction. As a result, the proposed feasibility study defines the set of production parameters and the types of equipment for which this technology is suitable, bringing rapid investment payback. The proposed feasibility analysis is validated by an industrial case study related to a tannery spray plant