Energy Management / Energy Audit

Boost your profit via an energy audit

Two programs offered by the U.S. DOE can help you improve your energy efficiency.

By Frank Healy, Fluke

For years, industrial and commercial facilities viewed their electrical utility bill as a cost of doing business. Then, energy costs began to spike as fossil-fuel costs rose to unprecedented heights – more than $100 per barrel in the case of oil. Concurrently, energy-efficiency technology innovations able to deliver energy savings with no sacrifice in performance (and sometimes improvements in product quality, production rate, safety, etc.) accelerated in development.

Even though oil prices have settled, the surge of interest in energy retrofits remains unabated as governments and environmentally conscious companies look to curb greenhouse gases blamed for climate change and utilities seek to extend the capacity of existing power-generation plants. And of course, the specter of higher fuel costs looms in the future.

American facilities have found a potential new source of profit margin by cutting their monthly energy bills and becoming more efficient. Specifically, significant savings and profits can be realized by performing energy audits and executing retrofits and upgrades at industrial facilities.

For example, the owners of an average small- to mid-size industrial facility could save 10% on their power bill and $42,000 annually by auditing energy use and implementing recommendations to upgrade equipment and change operations, according to data from a U.S. Department of Energy program. University professors and students in 24 locations across the United States are involved in the Industrial Assessments Centers (IACs). Data from those centers, the results of more than 16,000 on-site industrial assessments, suggest that savings at least this great are possible depending on the type of manufacturing facility.

The U.S. DOE has set up programs to help industrial companies curb energy costs and thus greenhouse gases. One of those completes in-depth assessments on plant operation to identify energy-efficiency improvement opportunities, minimize waste and pollution, and improve productivity. The IACs compile the data for their assessment for use by industry in a database accessible online (see Users can glean valuable information from the database by approximating potential electrical and natural-gas energy savings by taking a look at the average results obtained at similar industrial plants. The database also lets users identify frequently recommended efficiency measures for each industrial plant.

Another energy-savings estimate tool is the Plant Energy Profiler Excel, into which a user inputs annual energy use and cost data as well as a breakout of energy use by operating process or system in a given plant. A default breakout of energy use by production process is offered in the absence of the specific data.

Beyond the federal government programs, local utilities have launched customer service campaigns aimed at helping facility managers make better use of the power they’re consuming. Why do this? Utilities have capacity concerns, and it’s easier to curb waste than it is to build power plants. Even getting a new power plant approved through the tangled regulatory framework can take years. And the random oil spill or nuclear plant disaster shows just how limited the options are for generating new power.

Thus, electrical utilities have a keen interest in avoiding having to add to their existing generation capacity. And facility managers have incentives to reduce power waste and become more efficient. If a company’s profit margin is 5%, saving $30,000 in energy costs equates to sales of $600,000, and many energy-savings measures may have simple payback of several years or less.

Energy audit basics

A basic energy audit can help determine which operational function consumes the most energy per month. Many facilities have identified the easy targets – energy consumption that can be decreased without substantial investment as well as taking advantage of government energy-efficiency subsidies. Common examples include:

  • Fixing leaks in compressed air lines
  • Shutting off equipment and systems overnight instead of leaving them on
  • Upgrading lighting systems to more energy-efficient LED banks and motion-sensor switches.
  • Upgrading chillers to high-efficiency models
  • Adding controls to match mechanical equipment output to performance requirements

For more effective energy savings, it’s best to take a systems approach. Rather than replacing a component with something similar, start with end uses, then look at distribution systems, and finally look at the central plant. For a compressed air system, this would mean reconsidering wasteful end uses (such as sweeping the floor—get a broom!), then fixing distribution leaks, and finally considering a more-efficient compressor, which may now be sized smaller than the previous equipment.

Quantify energy waste

Add to those examples yet another major concern that can hit facility manager’s bottom line: dirty power. Energy engineers have known for many years that imperfections in the purity of power, such as harmonic distortion and load unbalance, caused performance issues in three-phase equipment and, in the case of power factor, diminished the usability of the distributed electricity. Utility companies sometimes even charge for excessive power factor.

It was only a decade ago the IEEE along with academics sought to quantify the amount of power made unusable by such imperfections. In two studies, one at an automobile plant and another at an industrial park, professors Vincente Leon and Joaquín Montañana at the University of Valencia in Spain were able to quantify annual energy savings from power quality adjustments. In the industrial park example, the utility was able to save $14,000 a year by installing time-control relays to disconnect a capacitor bank at night; and the automobile plant upgraded transformers and installed capacitors and regulator controls for a savings of $50,000.

Hailed as a breakthrough, their Unified Power measurement took recommendation of the IEEE-1459-2000 standard that defined the sources of specific wastes and calculated the energy wastes of reactive power, harmonics and unbalance in the electrical system. Now, portable handheld energy and power quality analyzers can deploy Unified Power measurement calculations to express power and energy data that directly quantify the waste energy in electrical system by measuring harmonics and unbalance waste in terms of kilowatts. The measurements also factor the cost of each kilowatt hour to calculate the cost of waste energy over a week, a month or a year.

Armed with handheld energy analyzers, engineers or electricians can log the energy to equipment known to consume large quantities of power and then quantify the savings to make a case to managers for improvements in their plants. The recommendations might include adding capacitor banks to resolve power factor issues or changing the type of electronic equipment. In the case of unbalance, recommendations might involve installing unbalance compensation equipment, or increasing the over electrical distribution system capacity. Even the installation of a harmonic filter will improve overall power quality and increase equipment reliability, efficiency, and lifespan and decrease downtime.

But with the new Unified Power capability, coming up with the cost of labor and equipment necessary to mitigate harmonics and unbalance as compared with the amount of energy wasted, becomes a relatively straightforward ROI equation. Once the changes are implemented, a routine of monitoring equipment with the handheld analyzers can be a way of ensuring smooth and efficient operations, and justifying the costs of upgrades and improvements at your facility.