The Top Five Energy Efficiency Measures for Industrial Businesses
The United States ranks first in energy wastefulness among developed nations. Government data shows industrial energy use is responsible for almost 30 percent of all U.S. greenhouse gas emissions, which means manufacturing operations are a significant contributor to this unfortunate head-of-the-class ranking. And the energy used by U.S. manufacturing plants totals $180 billion annually. Whether making steel, refining oil or canning vegetables, there is great potential for improving energy efficiency and our status as an energy waste offender. Reducing energy consumption is critical to maintain a plant facility’s competitiveness, especially at this time of global economic uncertainty and increasing concern for more environmentally-friendly factory operations.
Government statistics show that, on average, 30 percent of energy in buildings is wasted. Through the Department of Energy’s “Better Buildings Challenge,” which challenges American commercial and industrial buildings to be at least 20 percent more energy efficient by 2020, manufacturing facilities are working to improve their bottom line by saving energy in their plants. This translates to potentially billions of dollars saved annually. A focus on energy efficiency implies a focus on operational efficiency and a direct impact on profitability and business results. And with the president issuing a new goal during his February 2013 State of the Union address for the United States to cut in half the energy wasted by homes and businesses over the next 20 years, it’s clear energy efficiency will remain a top priority.
More efficient commercial and industrial buildings reduce the nation’s dependence on foreign oil, protect the environment, and save billions of dollars in energy costs that can be spent growing businesses, investing in new technologies, and creating jobs.
Manufacturing Plants: A Complex Energy Environment
Example Energy Reduction Plan for a Manufacturing Facility
With multiple independently-controlled systems, including the largest energy-consuming systems like compressed air systems, pump and fan systems, refrigeration and chilled water systems, process heat systems and boilers and steam systems, industrial facilities are complex.
Most industrial facilities strive for maximum efficiency, but facility and plant managers face many challenges: aging equipment, reduced capital budgets, disparate or legacy systems that refuse to integrate, a chronic shortage of trained personnel, and a team that’s often fighting fires instead of proactively managing energy. Faced with a need to cut costs or meet energy reduction goals, facility and plant managers are often asked for three deliverables:
- A prioritized list of energy savings opportunities.
- A solid business case for the high-priority projects.
- A reliable source of funds for the investment.
Historically, a major hindrance to effective energy management has been simply identifying the problems that are costing the most money so they can be addressed. To overcome that obstacle, data and analytics are today playing a starring role in energy management. Technology now helps manufacturing and plant facilities conduct audits that bring to life patterns showing how energy is misspent – whether from equipment in need of tune-up or repair, or “operator errors” like lights left on or thermostats set incorrectly. By gleaning insights like these, industrial businesses have the tools and information to prioritize limited resources for immediate results.
There are ultimately only two levers for industrial businesses to reduce energy usage: capital investments (better equipment) and operating adjustments (changing how energy is used). Capital investments have proven returns but often require a larger financial outlay that facility budgets don’t provide. But the good news is there are significant savings that can be recouped simply by making low- or no-cost adjustments to existing operating processes.
Best Practices for Energy Efficiency Improvements
Here are the top five no-cost or low-cost measures that will bring noticeable improvements in energy efficiency. These include things like identifying idle equipment, making simple operations and maintenance changes, or equipment retrofits, all which can deliver an immediate bottom line impact.
- Peak Energy Demand Identification: Peak demand charges can often equal 30 percent of an industrial organization’s monthly utility bill. Peak demand charges are typically calculated over the 15-minute interval when the organization uses the greatest amount of energy in a given billing period. Peak demand is impossible to determine simply by looking at a utility bill. But with real-time visibility of energy usage, demand peaks become obvious, including irregular peaks caused by intermittent use of high-voltage mechanical systems, improperly programmed building management systems, or other mechanical system failures. Many industrial businesses have regularly scheduled production shifts with relatively predictable demand curves. Industrial businesses can work with vendors to ensure high-energy-demand activity necessary to meet production demands don’t coincide with incidental loads that can be shifted or eliminated.
- Weekend Energy Use: Many industrial businesses have regular production shut downs (weekends, off shift periods, scheduled maintenance windows) that should see substantial reductions in energy demands. Without visibility into shutdown levels that data and analytics make possible, it’s hard to determine if optimal savings are being achieved.
- Weeknight Set-Backs: Looking at the amount of energy used during off-shift periods is another area where savings can be achieved, thanks to the availability of granular energy demand trend information. For instance, data can highlight shallow drops in energy demand, which potentially indicate few pieces of equipment shutting down during off periods. Industrial businesses can use new technologies to compare energy use over time to see how setback sequences change. Having access to historical demand data to create a relative performance benchmark is a key consideration when contemplating an energy efficiency strategy.
- Start-Up Spikes: Start-up spikes result when voltage jumps because multiple mechanical systems are turned on simultaneously. But by gradually ramping up mechanical equipment in a staged manner, excessive energy charges can be avoided without compromising production output.
- Compressed Air Systems: Compressed air is used in many industrial processes. Given the large electrical demands needed for air compression motors, up to 20 percent of total electrical use in certain industries can come from air compression systems. This makes these systems prime targets for energy efficiency measures.
The expense of compressed air equipment itself is often a fraction of the cost of operating and maintaining the equipment over time. So investments to reduce operating costs will create substantial savings over the lifetime of the system. There are several low- or no-cost measures that can address the expense of running compressed air systems. Some of the most common measures (e.g., performing an air leak survey and addressing those leaks, the selective use of booster compressors) have very rapid paybacks.
In one example, a food manufacturing plant in a 600,000 square-foot, 10-plus year-old facility had an annual compressor operation of 8,760 hours. The national average for leak load in manufacturing facilities is 20-30 percent of total compressed air use. However, the majority of leaks (which can occur any place where there is a fitting, connector, change of material or pneumatic device) are too small to be identified by sound or touch. By using ultrasonic detection equipment to identify small leaks in this noisy environment, leaks were tagged and characterized.
The result? A total of 440 cubic feet per minute (CFM) in leaks were identified, representing roughly 40 percent of total air demand – or the equivalent of about 100 hp required to feed the leak load.
In another example of a chemical plant, major energy savings were achieved thanks to control sequencing and installation of high-efficiency compressors. The existing system had four 350-hp compressors and three booster compressors, and it operated 24 hours per day, seven days per week. By conducting a simple compressor sequencing tune-up and replacing the four compressors with two new 300-hp compressors, the plant saved more than 2.7 million kWh in annual energy consumption.
These five measures, taken either individually or collectively, can help an industrial business enjoy significant cost savings, as well as spot anomalies and potential equipment failures before they happen.