Perspectives: Energy Saver

Optimize Electrical Systems, Part II

Take a closer look at electric motors and plugged-in loads for potential energy savings.

By Ven V. Venkatesan, Energy Columnist

Improving motor efficiency is the most common opportunity to save electricity. Several factors can decrease motor efficiency: poor maintenance and lubrication, misalignment, frequent starting and stopping, and improper sizing. Under-sized motors draw excessive current to do the work and eventually fail due to overheating. Generally, motors are correctly sized, but if change in loading conditions makes the motor under-sized, it needs to be replaced with suitable-sized unit. Over-sized motors can draw more current than required for the work, wasting energy. In such a case, reducing the motor speed with a variable frequency drive could lower the power draw to deliver the same work. For correctly sized motors, installing ammeters would help to ensure the motor is not overloaded continuously.    Installing a variable frequency inverter on AC induction motor drives is the most common energy savings project to reduce electricity consumption, especially for plants operating a large number of centrifugal pumps and fans. In the normal plant design, most of these pumps and fans are coupled with discharge-side flow control valves to meet the exact process requirement. However, discharge-side valve or damper control is inefficient for fluid flow control. Varying the speed of the centrifugal pump or fan is much more efficient.

Read more

More from this perspective...

Title

Implement Energy Efficiency Measures, Part III

Continuous monitoring of energy costs offers added benefits

12/20/2012

Implement Energy Efficiency Measures, Part II

Develop a detailed, successful implementation plan using these tips.

11/28/2012

Implement Energy Efficiency Measures, Part I

Use this 5-step approach to overcome implementation challenges.

11/01/2012

Conduct Fruitful Energy Audits

Follow these steps to properly allocate and monitor energy costs.

10/03/2012

Energy Saver: Initiate Your Energy Management Plan Right

A well-initiated plan will continuously generate positive results

09/04/2012

Manage Your Energy Management Program

Learn what roles make up a successful energy management program.

07/31/2012

Understand Energy Management Basics

Five key activities can help reduce energy use.

06/20/2012

Assess Your Energy Usage, Part II

Begin with a thorough self-assessment to reduce energy costs

05/17/2012

Assess Your Energy Usage, Part I

A thorough set of checklists can help determine where energy improvements are needed.

04/17/2012

Optimize Energy Costs in Refineries, Part II

Several options can improve condensate recovery.

03/20/2012

Optimize Energy Costs in Petroleum Refineries, Part I

Improve refining margins with more energy efficient measures.

02/21/2012

Optimize Energy Costs, Part II

Alternative process heating methods could offer attractive pay-offs.

01/25/2012

Optimize Energy Costs, Part I

Several petrochemical examples highlight energy efficiency.

12/20/2011

Save Energy in Water Systems, Part II

Recover cold cash from cooling water systems.

11/16/2011

Save Energy In Water Systems, Part I

Plants often miss opportunities to more fully use hot water.

10/13/2011

Don't Overwork Pumps and Fans, Part II

Several opportunities exist to reduce a fan's energy use.

09/14/2011

Don’t Overwork Pumps and Fans, Part I

Four simple steps present opportunities to reduce energy use.

08/22/2011

Recover Low Level Heat, Part II

Additional innovative options exist to recover such heat

07/27/2011

Recover Low Level Heat, Part I

This two-part series highlights innovative concepts for recovering such heat

06/03/2011

Optimize Your Compressed Air Systems

Five simple steps could improve air compressor efficiency

05/06/2011