Sammendrag
This paper describes the effects of increasing the voltage of distribution grids serving residential customers in Trondheim, Norway. Since more than 70% of the annual energy consumption of residential customers in Norway is attributed to heating purposes i.e. impedances, an assumption was that increased voltage would increase the load. However, temperature corrected results from a comprehensive regression analysis based on of hourly consumption and voltage of 480 residential customers during a year, indicate that the power consumption is independent on the voltage. The regression analysis shows with 95% confidence that the assumption of voltage dependency is not accurate. The natural explanation is that thermostats effectively regulate the impedances to meet the customers' energy demand independently of the voltage. The customer demand is recorded from Smart Metering, and more than 99.5% of the hourly intervals from each of the customers are available. The voltage and in-fed energy is metered in the transformer station. The observed reduction of distribution losses is in accordance with the independency of the load on changed voltage. The reduction of distribution losses contribute to make investments in Automatic Voltage Control profitable