Demand-Side Management Technology Workshop: Motors and Variable Frequency Drives

1. Demand-Side Management Technology Workshop: Motors and Variable Frequency Drives Sponsored by Basin Electric Power Cooperative with Western Area Power Administration April 6, 2009 Bismarck, ND

2. Motors and VFD Case Studies Cory Fuehrer, NPPD Dan Slottke, Precise Power Corp. with Dave La Brie, Precise Power/Husker Power Mark Tsatsos, Marathon Electric with Warren Bryan, L & S Electric

3. Nema Premium Efficient Motor/VFD Case Studies Increasing Efficiency of Electric Motors Saves Energy at Research Facility • Company 3M Center Maplewood, MN • Product Line Scientific R and D • Applicable Process Laboratory • Reductions 10,821,000 kWH (anticipated) Source: US Dept. of Energy – Energy Efficiency and Renewable Energy

4. Nema Premium Efficient Motor/VFD Case Studies Project Scope: This energy saving project was conducted at 3M Center, a 7.5 million square foot facility. The company formed a team that evaluated approximately 1000 electric motor systems in 29 buildings at the 3M Center. Source: US Dept. of Energy – Energy Efficiency and Renewable Energy

5. Nema Premium Efficient Motor/VFD Case Studies Examples of upgrades include: The reheat water supply system pumps hot water to the building supply air reheat coils. The air supply flow to the reheat coils is constant, so temperature control is achieved by regulating the flow of hot water. The building has five reheat water supply pumping systems, each with two 7-1/2 hp motors. Energy-efficient motors and VFDs were installed to better match the amount of water being pumped with the system requirements. In addition, tests conducted revealed that the system could perform satisfactorily with a lower differential pressure setting across the pump. Source: US Dept. of Energy – Energy Efficiency and Renewable Energy

6. Nema Premium Efficient Motor/VFD Case Studies Air is supplied to many parts of Building 123 by two 50 hp fans. The volume of supply air required varies with the number of exhaust fans running, which in turn depends on process activity and building occupancy. Fans were run constantly and controlled with dampers. The team installed a VFD on each fan to control airflow more efficiently and installed an energy-efficient motor on the one fan that did not have one.

7. Nema Premium Efficient Motor/VFD Case Studies Project Scope: NCI’s ventilation system uses nine supply fans (SF’s) and nine return fans (RF’s) to circulate high humidity air to maintain ambient conditions, cool process machinery, and control suspended particulate and airborne fibers. • Company NCI, Fresno, CA • Product Line Textile manufacturing • Applicable Process Raw cotton processing • Reductions 1,600,000 KWh Source: US Dept. of Energy – Energy Efficiency and Renewable Energy

8. Nema Premium Efficient Motor/VFD Case Studies Project Scope (Cont): While the qualities and volumes of air supplied and returned from each area remain constant in the system, seasonal variations occasionally cause minor changes in the ventilation rates. After determining that the ventilation system’s fans were significantly oversized, NCI retrofitted 15 of the 18 fans with VFDs. The remaining fans always ran at full flow and did not need VFDs. Source: US Dept. of Energy – Energy Efficiency and Renewable Energy

9. Nema Premium Efficient Motor/VFD Case Studies Results: Installation of the VFDs reduced the ventilation system’s total electricity demand from approximately 322 KW to 133 KW, a 59% drop. The energy efficiency gains were possible because the VFDs enabled plant personnel to fully open the fan control dampers and reduce fan speed. This results in a large drop in motor power consumption and allows the system to operate efficiently. Source: US Dept. of Energy – Energy Efficiency and Renewable Energy

10. Nema Premium Efficient Motor/VFD Case Studies Increasing Efficiency of Electric Motors Saves Energy at Research Facility • Company City of Long Beach, CA • Product Line Utility • Applicable Process Solid waste to Energy • Reductions 3,661,200 KWh Source: US Dept. of Energy – Energy Efficiency and Renewable Energy

11. Nema Premium Efficient Motor/VFD Case Studies Project Scope: After trucks discharge their loads SERRF’s 5,000 ton solid waste storage pit, large cranes deposit processable waste into one of three hoppers, where the waste is then pushed by hydraulic rams into one of three identical boilers. These balance draft boilers combust the solid waste, converting water flowing through the boiler tubes into steam that is used to drive a turbine generator. In addition to being equipped with one 100 HP primary air fan, each boiler has a 500 HP induced draft fan on the exhaust side of the boiler. Analysis of the original operating process demonstrated several key findings. Source: US Dept. of Energy – Energy Efficiency and Renewable Energy

12. Nema Premium Efficient Motor/VFD Case Studies Project Scope (Cont): First, to meet system requirements during startup, shutdown, and normal system operation, the induced draft fans damper settings covered the entire range from closed to 100 percent open. The average fan inlet damper setting, however, was 47% open. The New System: To increase system efficiency, the plant retrofitted each of the three induced draft fan systems with VFD’s designed to operate with the original 500 HP induction motors. This modification enabled plant operators to continuously modulate induced draft fan speed to maintain the boiler draft set point and allowed fan inlet dampers to be opened to 100 %, eliminating pressure drop due to throttling. Source: US Dept. of Energy – Energy Efficiency and Renewable Energy

13. Lunch and Technology Demonstrations

14. Demand-Side Management Technology Workshop: Motors and Variable Frequency Drives Sponsored by Basin Electric Power Cooperative with Western Area Power Administration April 6, 2009 Bismarck, ND