Problem:

• A monthly electricity bill of €50.000 considered too high when compared to similar plants.

Diagnosis:

• Measuring the energy consumption of steam boilers and boiler room area of the factory in case there is an excess consumption, measuring the energy consumption of fans and submersible pumps, measuring the energy loss occuring on the underground cables and monitoring all of the values.

Solution:

• Solution: 40 Energy Analyzer, 1 USB Converter and 1 Monitoring Software were used. The incoming and outgoing energy values were monitored for steam boilers, fans, submersible pump groups and underground cables by connecting Energy Analyzers before and after them.
• The measured values were monitored with the communication software on a computer in real-time.
• Close inspection of the energy measurements revealed that the 2 x 11.0 kW fans and 5 x 7.5 kW pump groups were insufficient. The pipe diameters were increased in order for these machines to consume less energy.
• Submersible pumps were working for 24 hours. The pump power was increased in order to decrease the operating time of the pump system and to adjust the operating periods freely.
• It was determined that the 85 meters long 120mm² diameter underground cable was overheating. It was replaced with a 240mm² diameter cable and a 20% drop in energy consumption was observed via the Energy Analyzers at both ends of the cable.
• 8 x 22 kW fans were working with star-delta starting configuration. 4 inverters were bought for €5.500. The fans were started with the inverters using soft starting configuration. An energy saving was achieved by decreasing the frequency of the circulation fans in the machine. It was determined that the water motors were consuming too much energy because there was not a pressure tank. A €910 worth pressure tank was installed to the system saving €35 per day.

Conclusion:

• Thanks to all these measures taken, the electricity bill of the factory was decreased to €36.300, cutting the energy cost by 30% and the energy started to be used this much efficiently. With the project cost at €18.500 (including frequency converters, water tank and cables) the payback period was less than 2 months.