Interest in energy efficiency is not new. During the last three decades, public and private companies, non-profit organizations, governments and consumer groups have collectively sought to push industry to adopt or accelerate efficiency initiatives. While significant successes have been achieved at many facilities, according to published reviews, the majority of companies have only made moderate levels of investments and patterns of implementations have been inconsistent.
Today, the imperative to improve industrial energy efficiency has never been greater. There are well-understood drivers for improving equipment and process efficiency including environmental constraints, peaking oil production and aging infrastructure. The growing level of public interest and public investment in energy efficiency during the past five years has quickened the pace.
Achieving energy efficiency is not an academic theory. It is a growing reality that must become a core management practice in all industrial facilities. The opportunity for enormous cost savings is compelling.
Think of it as end users having a large, accessible pool of low-cost fuel at their fingertips, and all they have to do is make the investment to tap this abundant source.
Why would anyone not take advantage of this opportunity? Isn’t this an essential component of any strategy to achieve a competitive advantage?
During the last decade, interest in these efficiency opportunities have increased, and even more important, end users have realized that many of the perceived barriers to achieving the associated savings can be summarily addressed and surmounted.
Clearly, the overall lack of progress has been due, in part, to a lack of understanding and appreciation of how efficiency drives cost savings. As a result, there has been a lag time in making the required investments.
Often, energy efficiency projects are perceived as ambiguous and, as a result, are considered less attractive than traditional capacity expansion and modernization investments. The old adage “when in doubt, don’t” should no longer apply to energy efficiency projects. The barriers, both real and perceived, are common across industrial facilities and will certainly require some level of innovation to overcome; e.g., providing information and training, dedicating resources (not bound by operations to focus on short-term fire-fighting issues) and appropriating proper levels of financing (capital that is not in competition with other high value projects that are focused on production).1
In industrial plants, managing energy consumption, not just supply, must become a critical component of the equation for improving profitability. When considered, process pumps, as an asset group, are typically the largest consumer of energy in the majority of continuous process plants. Furthermore, when you consider that every watt of power wasted by over-sized or over-throttled pumps becomes a destructive force that lowers overall process reliability, optimizing pump performance is the key to achieving a triple benefit—lower energy costs, lower maintenance costs and improved process control. This is an essential strategy for any plant management that wants to improve the plant’s sustainability, productivity and cost position.
Pump System Efficiency Opportunity
According to the Department of Energy (DOE), more than 13.5 million electric motors convert electricity into useful work in industrial process operations in the U.S. Industries spend more than $33 billion annually for electricity dedicated to electric-motor-driven systems. Industrial motor system electricity consumption is 24 percent of all U.S. electricity sold in 1994. Because nearly 70 percent of all electricity used in industry is consumed by some type of motor-driven system, increases in the energy efficiency of existing motor systems will lead to dramatic nationwide cost savings.
Improvements in motor systems as well as management practices can yield significant energy savings, up to 42 percent, according to a recently revised American Council for an Energy-Efficient Economy (ACEEE) reference manual - titled Energy-Efficient Motor Systems: A Handbook on Technology, Program, and Policy Opportunities. This report contains an in-depth analysis of motor system energy use and savings potential by market segment.
In most industries, the report identified centrifugal pumps as the largest consumers of electric motor energy. Also, among all rotating assets in the plant, process pumps had the highest overall potential for electrical energy savings.
This trend is consistent with the findings of a Finnish Technical Research Center published in a 1996 report, “Expert Systems for Diagnosis and Performance of Centrifugal Pumps.” The report revealed that the average pumping efficiency, across the 20 plants and 1,690 pumps studied, was less than 40 percent, with 10 percent of the pumps operating below 10 percent efficiency. Also, average motor efficiency was 81 percent with pump seal leakage being the fault that causes the highest downtime and cost. While this report is more than a decade old, these stats have not changed significantly when considering the state of today’s pump population.
The DOE motor efficiency report also noted that motor systems equipped with variable speed drives (VSD) account for only 4 percent of motor energy usage, compared to a potential for application on 18 to 25 percent of the total energy used by motor systems. Only the largest plants had implemented the most common kinds of system improvements and patterns of knowledge, even among the largest companies, is inconsistent.