Achieve Energy Savings in Plant Facilities

John M. Gross, Plant Engineering and Maintenance (PEM) Magazine

Whether it’s turning off lights, idling back process equipment and fixing compressed air leaks to energy audits and installing compressed air management systems, reducing utility costs to achieve energy savings in plant facilities can take several forms. As with any project, the return on investment should guide you on the projects that you select.

Let’s start with lighting and air leaks. While turning off lights and idling process equipment may generate a huge savings, it sends a message about conservation and preventing waste. The key is to not create any safety hazards and have a plan for start-up. Larger savings can be found with air leaks.

From my experience, air leaks happen over time and are often unnoticed or ignored. Air leaks can be detected the old fashioned way by listening for the leaks when the plant is shut down, or you can use an ultrasonic detector. The ultrasonic detector detects sound waves and can also be used for predictive maintenance.

Moving up the cost curve, you should consider an energy audit. The energy audit will identify ways to save energy and can sometimes spot tax or utility bill savings. Like most audits, you will receive some practical suggestions along with some off-the-wall ideas. Evaluate the report and use your judgment on what to implement. Remember, you’re trying to reduce energy costs—not win a high school science fair.

One suggestion that always raises questions from senior management involves the installation of new full spectrum, high-bay fixtures and bulbs. The questions stem from the fact that these fixtures look like the old fluorescent fixtures, which we replaced with metal-halide fixtures years ago. These lights, however, really work. Lighting levels will go up and you save money. Another consideration is how large is the power factor in your plant? Are you being charged for it by the local utility?

Don’t forget the power factor is the measure of reactive power, which results in increased current flow between the power source and the load. The power company charges the power-factor correction surcharge to cover the undocumented additional power. Reactive power is typically caused by the inductance from electric motors and can be corrected by adding capacitors to the electrical system. The cost for the capacitors is based on their size, which will depend on where they’re placed in the circuit.

Because of the decisions and resultant cost, think carefully and don’t be afraid to seek additional advice before making an investment.

Typically, power-factor correction usually works best when applied to larger motors. To justify the cost, make sure that you understand electricity savings before making any purchases. My last suggestion deals with compressed-air management systems. These systems save money by storing compressed air at higher pressure than your plant system, while allowing compressors to idle. As a result, you save money.

These cost-effective systems can smooth out your plant’s air pressure. It can get expensive, however, if you have older compressors and don’t have a large air-storage system. Years ago, I lucked out when installing one of these systems. I found three 5,000-gallon tanks sitting in our sister plant’s “bone yard.”

The key to making these systems economically viable is being able to store the compressed air at a 10 to 15-psi higher pressure than the plant system. If you can store the compressed air at 25-psi difference, then you will see some real savings. As expected, companies selling the system will be more than happy to help you calculate the savings. They will also know if you qualify for any helpful energy savings funding that’s available from utility companies or the government. Regardless of the economic situation, maintainers should always be looking for ways to reduce cost. When you’re considering and selecting energy savings options—do your homework. Quantify your savings and have a realistic installation and start-up plan.

Click here to learn more about Energy Optimization in your Plant Facility.

John M. Gross works as a Six Sigma master Black belt and lean manufacturing manager for a Tier 1 automotive supplier. He’s the author of Fundamentals of Preventive Maintenance and coauthor of Kanban Made Simple. John is a professional engineer as well as a certified plant and quality engineer. You can reach him by email: john@drivingchange.com.

The Trouble with Torque in Electrical Connections

The secret to making and keeping reliable electrical connections is contained in two elements: start with clean contact surfaces, and apply high force. Clean contact surfaces are a function of cleaning procedures, including joint compounds, and will be covered in a future article. Application of high force is the subject here. The trouble comes about because the terms "torque" and "force" are incorrectly used interchangeably. Force is NOT torque. Force is a function of torque.

Installations and Inspections of Corner-grounded Systems

Electrical systems are grounded to limit the voltage imposed by lightning, line surges, or unintentional contact with higher voltage lines and to stabilize the voltage to earth during normal operation. Electrical systems can be grounded in several ways. There are induction grounded systems, resistance grounded systems, and high impedance grounded systems among others. The most common grounded system is the solidly grounded system, where there is no intentional grounding impedance in the earthing or grounding circuit.

Some Plain Talk About Nuts and Bolts: Part 1 of 2

When you look over the list of projects you’ve worked on in the last 20 or so years, it’s amazing how many involve fastener problems. Some are relatively easy to solve, especially where careless practices have resulted in fatigue failures. Other problems are much more sophisticated, such as aluminum rivets clamping aluminum sheet metal that failed from galvanic corrosion! In Part 1 of this series, Some Plain Talk About Nuts and Bolts, a Q&A addresses some of the important points connected with common bolting practices.

Who is Driving Your Leadership Career?

So you want to be a leader! Your leadership career is a journey, and just like any journey, it requires a driver. The question is, who is driving your leadership career? Is it you, or are you letting external forces take the wheel? Taking control of your career is essential for your personal and professional growth. In this article, I will explore the importance of you taking control and offer some insights from my 45 years in the world of work that may help you steer your career in the right direction.

Revitalizing an Aging Grounding System

In 1997-98, the facility was considering replacing the aging (1972-73) high, medium, and low voltage equipment because of several operational and maintenance problems with the breakers. We also were concerned about the overall grounding scheme of the facility. To find out the existing status of the grounding system, we procured architect/engineer (A/E) services to check and confirm the overall validity of the facility-grounding scheme.

Understanding the 'Diesel Effect' and How it Damages Hydraulic Cylinders

I was recently engaged by a client to conduct failure analysis on a large (and expensive) double-acting cylinder off a hydraulic excavator. This cylinder had been changed-out due to leaking rod seals after achieving only half of its expected service life. Inspection revealed that apart from the rod seals, which had failed as a result of the 'diesel effect', the other parts of the cylinder were in serviceable condition. The diesel effect occurs in a hydraulic cylinder when air is drawn past the rod seals, mixes with the hydraulic fluid and explodes when pressurized.

Achieve Energy Savings in Plant Facilities