TRU Energy Monitoring for Potential Cost Saving in Electricity Bills for Cathodic Protection Units: South African Case

Abstract

Reducing the electricity bill in the industrial sector is an important problem worldwide. This study focuses on the awareness of industries to Cathodic Protec-tion (CP) energy conservation and on the potential of reducing electricity bills by a change of tariff or making use of renewable energy. Due to the frequent increase in energy cost at a significant rate, many indusial consumers are looking for ways to reduce the monthly electricity bill. The study aims to identify if it will be possible to use options such as renewable energy to supply CP systems, or if a change of tariff can help reduce the monthly bills. To achieve this, a real-time energy-monitoring device “Efergy E2” was installed in one of the Transformer Rectifier Units (TRU), the monitored TRU is located at Ndwedwe reservoir 2 in the areas of Durban. Among other benefits, the hourly load data analysis can provide the detailed characteristics of load demand, define the consumption patterns and can help to identify where the consumer could reduce the electricity bill. The results indicate that the load is almost constant throughout the day and changing to Time of Use (TOU) tariff does reduce the bills. However, the fixed charges amount to 11 times energy charges, hence the best way is to make use of renewable energy rather than changing a tariff.