Modelling of PV Power Station Exploitation Process, Supporting Wastewater Treatment Plant Energetic System

Abstract

The paper presents a new method for determining the indicator of energy demand coverage from PV micro power station. For verification process we applied this method in wastewater treatment plants. The investigated parameter was the electricity demand of these facilities. The developed method is based on two indicators $W_{I(t)}$ and $W_{P(t)}$, respectively the insolation and the power demand index. Mean annualized data were used to develop the insolation index, while the power demand index was based on actual power demand of wastewater treatment plant. Once the load profile has been defined, it has been modified by the signum function to the day/night interval, and then the power demand indicator has been determined. The intersection point of these two indexes developed on a common basis can be interpreted as a degree of energy demand coverage of objects with known load profile. Described author’s methodology was verified in the first six months of the first half of the year in the rural wastewater treatment plant, which is integrated with a 100 kW PV micro power station. The energy demand of the plant treatment in each month exceeded the model’s value for about 10–17%. That was caused by 30% PV power station oversizing.