AC Induction Motors motors literally are everywhere! Almost every mechanical movement that you see around you is caused by an AC (alternating current) electric motor.
They are everywhere and used by everyone. However, they have a fundamental flaw – they often waste unnecessary amounts of energy. An incredible 50% of the world’s energy production is consumed by motors!
Hence this article is of great interest to all concerned with saving energy – through developing motors or by using technology such as the different sorts of motor controllers. The article from University of California – Riverside looks at the importance of energy efficiency with regards to motors in HVAC systems.
Energy efficiency efforts tend to focus on things such as lighting and insulation. But, in fact, motors that run heating, ventilation and air conditioning (HVAC) systems are the largest user of energy in buildings.
At the same time, motor related efficiency requirements are relatively lax. There is no independent verification of motor efficiency, the equivalent of cutting out the Environmental Protection Agency and allowing car makers to say how many miles per gallon their vehicles get.
Sadrul Ula, who is research faculty at the University of California, Riverside’s Bourns College of Engineering Center for Environmental Research and Technology (CE-CERT), is trying to change that. He recently received a $385,000 grant from the California Energy Commission to evaluate the efficiency of HVAC motors in building through testing on-site and in a soon-to-be built facility at CE-CERT.
“Everyone turns off lights or bathroom fans,” said Ula, who is also managing director of the Winston Chung Global Energy Center at CE-CERT. “But, no one turns off motors. The awareness is not there.”
In recent years, large-scale clean energy projects, such as solar and wind farms, have generated many headlines, pushing energy efficiency efforts to the side. But those relatively simple energy efficiency steps can have a large impact. A 2009 report by McKinsey & Company found the United States could reduce annual energy consumption by 23 percent by 2020 by deploying energy efficiency measures.
In California, nearly 47 percent of electrical energy consumption was used by commercial buildings. Motors that create that energy tend to operate at 5 to 10 percent below optimal efficiency, Ula said. Increasing that efficiency can have enormous implications.
For example, a 5 percent reduction in energy use in California’s commercial sector is equivalent to 6 billion kWh savings per year, or the annual output of two to three average-sized power plants.
As another example, a 700 horsepower motor pumping water in a municipal water supply system that runs at 75 percent efficiency for 10 years will consume about $5 million in electricity. With a five percent increase in efficiency, $250,000 in electricity costs could be saved during those 10 years.
Some experts, including Ula and others at the CE-CERT, believe the lack of attention to proper sizing and efficiency evaluation of large HVAC motors is a major reason why HVAC systems in commercial buildings in California use 47 percent of power generated. The national average is 36 percent.
Motors tend to be improperly sized and inefficient for several reasons.
Maintenance personnel tend to use less efficient oversized motors because of pressure to keep HVAC systems operational. Also, many building managers repair damaged motors, which can lower efficiency significantly. And, new buildings can end up with oversized motors because only architects and civil engineers are involved in the design stages. In addition, there is a shortage of engineers with knowledge of electrical power and energy throughout the US.
With the grant, Ula, and two co-principal investigators, Matthew Barth, director of CE-CERT and an electrical engineering professor, and Alfredo Martinez Morales, managing director of the Southern California Research Initiative for Solar Energy at CE-CERT, and graduate and undergraduate students, have three objectives.
One, measure energy use of large HVAC motors on-site under actual operating conditions in office, institutional and commercial buildings. They plan to start with buildings on campus, move to off-campus government buildings in the Riverside area and eventually test building in other parts of the state, to take into account different weather conditions.
Two, they plan to set up a large motor testing facility at CE-CERT. The new independent test facility will be the first of its kind in California and only the third in the United States. Other facilities are located in Oregon and North Carolina.
Three, evaluate commercial and in-house software used by architectural and engineering firms designing HVAC systems.