A recent study, performed by the ABB Group in which 317 senior executives in manufacturing were surveyed, highlighted that “77 percent of manufacturers say that energy efficiency will be a critical success factor for manufacturers’ profitability in the next 20 years,” due to the high cost of energy and uncertainty with energy prices and supplies. Despite this overwhelming endorsement for energy efficiency, “Just 39 percent of respondents have invested in more energy efficient equipment in the past three years, versus 40 percent in 2011.”
This is largely in part to high capital expenditure with longer than desired payback periods. Yet, the manufacturing energy efficiency landscape has changed immensely over the past five years. While many energy efficiency options have been available for over a decade, the majority of utility-administered incentive monies were doled out for lighting retrofits. Today, more equipment, such as HVAC systems; energy management systems; motors, pumps, drives, and controls; building envelope improvements; and more can be incentivized, supplying manufacturers with greatly improved payback periods when moving forward with green building projects.
The purpose of this manufacturing energy efficiency guide is to address ways in which energy is consumed in manufacturing facilities and discuss energy efficient options that can reduce overall costs by an average of 10-15%.
Energy Consumption in Manufacturing
According to a 2012 energy and greenhouse gas emissions analysis, prepared for the U.S. Department of Energy, the U.S. manufacturing sector consumed 28% (27.6 quads) of all energy in the U.S. in 2006. According to Energy.Gov, in 2012, the manufacturing sector accounted for 25% of U.S. energy consumption. The manufacturing sector has been, and continues to remain, one of the most energy-intensive sectors in the U.S. and around the world. For manufacturers, even a 1% decrease in electricity costs can mean enormous savings.
Energy Management Systems
An energy management system (EMS) is a set of computer-aided communication channel system tools that can monitor and optimize a building’s performance using real-time building energy usage data. The technology to achieve this is known as a Supervisory Control And Data Acquisition (SCADA), which monitors and controls industrial, infrastructure, and facility processes. An energy management system is controlled through a human-machine interface (HMI), often represented by an energy performance kiosk. Through this HMI, a facility manager has a suite of analytical solutions with real-time visualizations to make operational adjustments.
Benefits for facility managers include:
- Implement best practices in daily operations
- Improve facility productivity and performance
- Standardize processes for sustained performance improvements over time
- Reduce equipment peak load and overall energy costs
- Reduce harmful carbon and greenhouse gas emissions
- Reduce risk of supply shortages and energy price fluctuations
- Transmission loss reduction
- Deferred capital expenditure
Energy Benchmarking
The concept of energy benchmarking helps to answer questions such as “How is our energy being used? and “How can I improve it?” An energy management system can take real-time facility data and compare it to other industry standards that closely resemble your operations, so you are able to compare and strategize. Ultimately, performance data can be utilized to standardize practices and improve facility performance.
HVAC
An HVAC system can consume between 40-60% of a building’s total energy. Yet, HVAC system purchases and repairs can result in large capital expenditures. Due to capital barriers, many facility managers continue to depend on the originally-installed systems, or those which may have had minimal repairs or upgrades. Even with HVAC systems that undergo routine maintenance, there are common signs of system inefficiency. The following checklist are items an energy efficiency consultant can check when evaluating an HVAC’s performance:
- Dirty filters, condenser & evaporator coils, and ventilation ducts
- Disabled dampers
- Ventilation duct leakage
- High load capacity
Dirty parts and equipment are a leading cause of health hazards in the workplace. Furthermore, disabled dampers and ventilation leakage can account for 20-40% in energy loss. An energy inefficient HVAC will run only at 60-70% of its full effectiveness. Compound this with 20-40% of heating and cooling loss through ventilation leakage, and you’re looking at enormous energy waste.
HVAC systems have a lifespan of 15-20 years; however, they only run efficiently for about 10 years. If your HVAC system is over 10-years-old, or requires constant repairs, upgrades to your system can reduce energy costs by 20-40%. Below are some recommendations to improve HVAC performance:
- Routine professional maintenance
- Install an economizer
- Implement controls
- Reduce load capacity
- Educate your workforce
Depending on the age and efficiency of your HVAC system, it may need replacing. Have an energy efficiency consultant inspect your system and evaluate its Seasonal Energy Efficiency Ratio (SEER) rating. Older HVACs will have a SEER rating of 6 or less. Modern HVAC standards are set at 13. To put these numbers into perspective, a SEER rating of 13 is 30% more efficient than a SEER rating of 10.
Motors and Controls
Motors and controls are simple upgrades facility managers can make to HVAC systems to improve performance. Motors combined with variable frequency drives (VSDs) can optimize fan speeds to run as demand-response. An economizer, which was outlined above, is a device that senses both internal and external air temperatures. If the outside air temperature is optimal for cooling, the economizer will switch off the HVAC condenser and utilize the outside air. On average, this reduces annual energy costs up to 30%.
Compressed Air
Compressed air systems are one of the most inefficient applications in manufacturing plants; they are the leading cause of energy waste. On average, they waste 80-90% of their energy use. As a result, compressed air systems have the largest potential for energy efficiency improvements.
Preventative maintenance can be taken to improve performance. Air leakage, often ignored as general HVAC background noise, is the most common form of energy loss. Age and general wear and tear has considerable impacts on air duct efficiency. Routine maintenance, which includes checking vents for leaks and ensuring all valves, couplings, and fittings are connected and working properly, is highly advised.
Lighting
Lighting upgrades are the most common energy efficiency application for commercial and industrial businesses. On average, lighting upgrades can save commercial facilities up to 30% on annually energy costs. Lighting technology is comparable to advancements in cell phone technology; every year significant improvements are made to new products to increase capability and efficiency. Lighting technology is more than simply retrofitting an inefficient lighting fixture with a more efficient fixture. Lighting retrofits, combined with lighting controls, such as occupancy sensors, relays, and logical programming, allow buildings to operate more intelligently through user-controlled settings. Typically, a facility that had lighting upgrades installed in 2013 can find energy savings with new, more advanced lighting and lighting control technology in 2016.
Bottom Line
The energy efficiency landscape is not what it once was, even only a few years ago. Today, energy efficient equipment saves more energy, is more technologically advanced, and has more data and reporting capabilities. Utility companies continue to expand on the number of mechanical upgrades that are incentivized through energy efficiency programs. With energy costs a constant concern for manufacturers, finding any way to reduce operating costs is of paramount importance. Consult with a professional to examine what manufacturing energy efficiency options are available for your facility.