Offsetting rising energy costs
Dec. 2, 2011
In a recent conversation with the CEO of a large Southeastern power company, he related how pending Environmental Protection Agency regulations may reduce reliability and increase costs for everyone. Although he was referring to retail consumers, I immediately thought of my client base of food processors who are burdened with huge utility bills every month.
Energy costs in states where energy companies have been recently deregulated and who are heavily reliant on coal could see energy costs increase 10 percent to 60 percent. Of course, energy costs can and will be negotiated by corporate management and power company representatives, but costs are going to increase. Regardless of the price of energy, the responsibility falls to the maintenance department to control the actual energy usage. So, what should maintenance departments be doing now to prepare for the inevitable?
Maintenance departments are integral to ensuring equipment runs at peak performance. Yet, in many cases, maintenance departments don’t even see actual energy costs. So, the first thing to do is to analyze at least the previous year’s data. Keep in mind, though, that two year’s worth of data can confirm peak costs due to seasonality. Often the energy bills will be sourced in accounting where the focus is on dollars. Unfortunately, with rate changes at different times of the year (or possibly even the time of day) this is a lousy comparison. What you need to know is how much actual energy is consumed and when. Depending on the energy source, these will be expressed as kilowatt-hours for electricity or British Thermal Units (Btu’s) for thermal energy. (See figures 1 and 2)
Between cooling the production areas, the work in process coolers, the freezers and the ice makers, the largest cost of energy in processing facilities is often refrigeration. One of the largest wastes is improperly sized units. How many production facilities are the same cubic feet in size today compared to when the facility was built?
When plant-remodeling projects are designed, refrigeration units are checked to make sure the unit will handle extra loads. But are all variables taken into consideration? One of those examples is their location. How will air flow change in the facility? Will the result be a cold spot at one end of the room just to maintain minimum required temperatures at the other end of the room? These variables can cause units to over-cycle or short-cycle costing thousands, maybe tens of thousands of dollars a year.
While it may technically be the correct unit, it might not be the most efficient when all factors are considered. And, while Occupational Safety and Health Administration regulations may be the motive for a rigorous preventive maintenance program and a comprehensive paper trail for ammonia-based refrigeration systems, it is the associated energy savings from keeping equipment at peak performance that can be the ultimate payback. Making sure compressors are running at peak performance, especially when loads are the highest, is imperative to controlling energy costs.
Depending on the size and age of facilities, lighting can be another large contributor to energy consumption. Often, the most efficient lighting does not provide the best color light to perform work critical to food production. More often than not, rooms are over-lit while work stations are under-lit. It seems equipment and production lines are always on the move in food production facilities, so it is important that task lighting follows the work station, while room lighting is kept adequate but not over-lit.
The electrical system of the facility can not only cause bodily harm, but it can waste a huge amount of energy. Oversized and undersized electrical motors, electrical panels with loose wires or breakers running close to their maximum load can all waste energy, emitting that wasted energy as heat. This is where safety and efficiency cross paths. It is imperative that proper sizing of motors and proper maintenance of the gearboxes to which they are attached be completed.
In cold rooms, a motor or gearbox that is hot is broken or incorrectly sized. A comprehensive list of all motors and their specifications can usually be accessed through your computerized maintenance management system (CMMS). An analysis of the list should identify the largest potential energy consuming motors. Starting your maintenance review of these motors from the greatest consumers of energy will provide you with more bang for your buck.
As energy prices rise, companies are also getting more creative in their sourcing of energy. Boilers can switch back and forth between fuels, but some processing facilities are capturing methane gas from their wastewater treatment facilities to offset thermal energy needs. There are also agreements with protein by-product companies to exchange their by-products for bio-diesel.
Of course, there are alternative sources of energy, namely solar, which can often offset some energy costs. Currently, the ROI on these type of capital expenditures depend on tax-related incentives. While the cost of solar panels are coming down, expect a multiyear payback regardless of tax incentives.
The bottom line
The ROI of reducing energy consumption is generally easily tracked once all the metrics and conversion factors are identified. It is up to the maintenance department to keep the effort front and center on a daily basis. There are more energy saving opportunities, most costing little to implement. So, become a detective and start hunting through your facility in search of wasted energy.