The scale of industrial energy use in the US is significant. A 2019 study by the US Energy Information Administration (EIA) showed that the American industrial sector made up around 32% of total energy consumption in the country. In total, over 26 quadrillion Btu (British thermal units) was used, with bulk chemical, refining, and mining industries rounding out the top 3 in terms of consumption. Even though these numbers may seem sky-high, it’s not all that surprising considering that the average American manufacturing facility consumes over 536,000 Btu of natural gas and 95.1 kWh (kilowatt-hours) of electricity per square foot every year.
This is a pretty jarring stat. Although, if you are a facilities manager, it likely isn’t surprising to you that industrial operations consume a large amount of energy because you’re paying for it. So, how can you identify large energy draws and make your facility run more efficiently? An energy audit. Although this is a simple answer, it’s not a simple process. Each and every facility has its own equipment and operating procedures, meaning that there isn’t one set checklist for a facility.
We’ll cover, everything that you need to cover on your audit, so that you can successfully cut back on energy consumption and save money. We’ll also provide a PDF checklist at the end to facilitate your industrial energy audit.
Industrial Energy Audit- What You Need to Know
The Initial Walk-through
The purpose of the initial walk-through is for the energy audit team or individual auditor, whoever it may be, to become familiar with the facility that they are surveying. This gives them a chance to go through the processes and utilities that they will audit in more detail later. During the walk-through, you can observe a baseline, which will tell you what extra measurement and data collection are needed for the audit.
Collect Energy Bills and All Available Data & Information
Gather energy bills and all other current and historical energy- and production-related data and information at the beginning of the audit process. The more historical data available, the easier it is to understand the typical operating procedures of the plant at differing times of day, in various seasons, and under diverse production conditions. The data that can be
collected at the beginning of an energy audit includes the followings:
• Energy bills and invoices (electricity and fuels) for the last 2 to 3 years
• Monthly production data for the last 2 to 3 years
• Climatic data for the period in which the auditing is conducted
• Possible archived records with measurements from existing recorders
• Architectural and engineering plans of the plant and its equipment
• Status of energy management and any energy-saving measures implemented
• General information about the plant (year of construction, ownership status,
renovations, types of products, operation schedule, operating hours, scheduled shutdowns, etc.)
Conducting the Final Analysis
The initial audit helps you to better understand how your facility uses energy by providing a general picture of the facility’s daily operating procedures. This gives you everything you need to prepare for and undertake any necessary changes in the audit plan.
In the analysis step, a flowchart can be drawn up to show the energy flows of the system being audited. An overview of unit operations, important process steps, areas of material and energy use, and sources of waste generation should all be included in this chart. This seems like a skippable step, but trust us it will make things much easier later on.
You’ve Identified the Problems, Now What?
The Quick Fixes
Plan a Walk-Through Audit
The first step to finding ways to boost your facility’s energy efficiency is to plan a walk-through audit. This can include several of the points that we will touch on in this guide, and others that may be specific to your industry. Download the Lawrence Berkeley Laboratory’s guidebook to use as a resource for your energy audit.
Reduce Unnecessary Equipment Idling
Certain industrial equipment needs to be powered on for long periods of time, since it can’t be turned off between uses. As a result, it is often left idling. To cut down on unnecessary idling, make sure to post power-down schedules and procedures for every piece of equipment in your facility. This can make your equipment last longer and result in fewer maintenance calls – in addition to saving on energy costs.
Smaller electronics like computers, televisions, and coffee pots use energy when they are plugged in but not in use. Check that the energy-saving features on computers and printers are activated, and turn them off when they are not in use. You can also install smart power strips, which detect when devices are powered off and cut their power, reducing overall energy usage and phantom loads. Also, look for smart strips with an occupancy sensing feature, which is controlled by a motion detector.
Use Space Heaters Efficiently
It is best to use space heaters with smart power strips and occupancy sensing for these energy-sucking devices. Keep in mind that if your employees need space heaters to stay comfortable when they work, it is likely a sign of inefficient HVAC system control.
Reduce Lighting Usage
Another extremely simple option is to turn off lights when they are not being used. You can save substantial energy this way, especially for areas where lighting is set up to provide full coverage (like on a factory floor). Timers and occupancy sensors are great tools for saving energy with little to no effort. A less costly option (that involves a little habit-forming) is to encourage staff to switch off lights as a part of their closing duties.
“Economizing” Your Air Intake
Air-conditioning systems often use an economizer vent, which measures outside air temperature and draws cooler air into your building. When your economizer draws in cool air, your air intake unit doesn’t need to work as hard, leading to reduced energy consumption and an increased lifespan for your system. Most air intake systems allow economizers to be fixed on the roof, and there are several kinds available depending on the climate in your facility’s location, and the complexity of your HVAC system.
Investing in Your Facility
Install Programmable Thermostats
Some industrial facilities have energy management systems for controlling temperature. But, even if your building doesn’t have this capability, you can use a programmable thermostat. These devices are commonly used at home, but can also be used in an industrial setting to set lower temperatures when there is no one in the building, and to regulate swings in temperature throughout the day.
Find the Right Lighting Controls
We have already touched on the importance of turning lights off when not in use, and other controls like dimmers and photosensors can also be used to save on energy costs. However, you will need to confirm that your lighting type is compatible with lighting controls.
High-intensity discharge (HID) lights do not work at all for this purpose, since they have longer startup times than fluorescent and LEDs. Dimming works well for fluorescent bulbs, although it has a negative effect on their lifespan. LEDs are ideal for dimmers since they can be wired to adjust with a photocell timer, which makes them even more energy-efficient than other lighting solutions.
Make Your Vending Machine Run Green
Vending machines should be powered down when there is no one in your facility. This can be done using occupancy sensors, and doesn’t have any effect on the quality of the products inside. A 2 to 5 degree Fahrenheit temperature rise during off-hours can lead to 30% energy reduction per year, which is between $100 to $150 in energy costs per machine.
Maintaining Equipment and Systems
Process heating can be a large energy draw for industrial facilities. There are ways to improve energy efficiency for this system, which can result in a 5 to 15% reduction in energy consumption (according to the US Department of Energy). The DOE maintains a knowledge base of best operating practices for process heating, which can be used to determine how to achieve energy savings with your system. Part of this is their Process Heating Assessment and Survey Tool (PHAST), which allows you to “plug in” information about your facility. It then records the annual energy use of our equipment, and recommends energy-saving methods tailored to your building.
Boilers also take a lot of energy to run, and a lack of proper maintenance results in lost heat in the boiler stack or boiler water. Set a routine for treating boiler water to prevent overheating and reduced efficiency from debris that accumulates inside the water side. In addition, lowering the stack temperature with a day/night switch and installing an economizer (which cuts down on wasted flue gas and keeps the boiler heated) are great first steps to getting more efficiency out of your boiler.
Check valves and hoses for leaks periodically with an ultrasonic leak detector, and make any necessary repairs right away. Poorly maintained systems with leaks can waste anywhere from 25% to 35% of their energy, which can increase costs by double. A leak detector is something to consider, as it provides benefits in the long term and can even pay for itself in prevented costs in six months or less. In addition to checking for leaks, we also suggest cleaning intake vents, heat exchanges, and air filters often, which will help keep your air compressor in order.
Energy loss often happens when air leaks through a building envelope, especially in the gaps between doors on loading docks. Leaks of any size can send your heating and cooling bills skyrocketing. Regularly check for gaps in door seals and prioritize repairing them. Also, ensure that your employees keep doors closed when not in use.
Aside from changing the actual type of bulb that you’re using, there are many ways to make sure that your lighting is efficient. An easy way to do this is to simply make sure that the fixture is clean. Dirty bulbs and mounts have negative effects on a light’s lumen output and lifespan.
Air filters should be replaced monthly, or even more frequently if they are meant to process heavy particulate matter. In addition, buildings near highways or construction sites (which kick up particles into the air) should have more frequent air filter replacements.
A small leak in your rooftop HVAC unit can result in wasted energy. Check for leaks in your unit quarterly, especially in cabinet panels and ducts. Cleaning the unit’s condenser coil is another cost-effective upkeep method. Dirty condenser coils increase condensing temperature which results in unnecessary power consumption. Over a year of operating a 10-ton unit with a condensing temperature increase of 10 degrees Fahrenheit, this can add up to $120 in electricity costs. Check your condenser coils for debris every four months, and clean them annually.
Long Term Energy Efficiency Solutions
Upgrade to Efficient LED Lighting
Surprise. One of the best ways to save money is to upgrade to LED lighting. Metal halide and high-pressure sodium lamps are on the way out, and LED technology is the clear choice for those looking to upgrade. LEDs can offer significant efficiency, controllability, and performance benefits over HIDs and every other type of bulb.
Try Wireless Controls
Dimmers and occupancy sensors, give you control over your lighting system and help you save money on electrical bills. Some of these wireless controls allow you to conveniently monitor your settings using a mobile app, allowing you to turn on fixtures only when they are needed. They are easier to install than wired systems thanks to wireless mesh networks, meaning less costly installations and reduced downtime.
Smart Lighting Layout
Believe it or not, it’s just as easy to over-light an area as it is to under-light one. And, while a dimly lit area poses obvious problems, over-lit spaces are just as harmful. They run up electricity bills and cost you hundreds of dollars. To prevent this, use a lighting plan when designing lighting for your facility.
Install Efficient Signage
Install LEDs in your exit signs and other signage to reduce energy and maintenance costs, especially compared to CFL and incandescent lighting. You can use Energy Star’s exit signs savings calculator to determine how much you can save by making this change.
Many commercial and industrial buildings have loading docks for easy loading and unloading. However, open loading dock doors allow heat to escape, leading to wasted energy. Ensure that doors are closed and sealed properly whenever they are not in use. You can also install loading dock doors that automatically close, or utilize a compression seal – which produces an airtight seal between the trailer and the dock. This is especially useful for warmer climates.
Providing efficient heating for an industrial building can be difficult when there are so many different functions taking place. Heating will be different for workers in offices, maintenance rooms, and on the factory floor – which means that a fully centralized heating system may not be the best option. One solution is installing radiant heaters, which transfer heat directly through walls, ceilings, or floors. Hydronic systems are particularly energy-efficient, to the point that they are recommended for off-grid homes.
High-volume, low-speed (HVLS) ceiling fans use their size (many are 7 feet in diameter) to move larger amounts of air and improve circulation in your building. HVLS fans can lower the temperature by as much as 6°F. During the colder months, these fans redistribute warm air that rises to ceiling level, meaning they promise energy efficiency year round.
“Cool” Roof Coatings
A cool roof is coated with highly reflective paint (usually white), which reflects sunlight and absorbs less heat than conventional roofing. This change can reduce cooling needs by anywhere from 15% to 20%. To find out more about how to implement this in your building, review the DOE’s Energy Saver Guide for Cool Roofs.
Increasing Efficiency With LEDs
As you can see, there are many, many different ways to streamline the operating procedures at your facility. An industrial energy audit is a great way to periodically take note of how well your facility’s equipment is functioning and identify any problem areas and address any issues. Energy audits help you save money by highlighting areas where things are performing as intended. However, there are also many short term actions that you can take to do the same thing. Turning off lights and adjusting indoor temperatures will help you save money. But, where you’ll really see huge savings is in your long term adjustments. Below, we have a sample downloadable checklist. After downloading, take a look at your facility’s operations and identify large energy draws, and add them to the list.