Much has been said and written about industrial energy efficiency in recent years. The U.S. Dept of Energy estimates that 37% of our natural gas and 29% of our electrical supply goes to fuel industry. That’s a big target and the DOE has their sights on it. They have begun to understand that mandating minimum efficiencies for components, like motors, only has the potential to improve efficiency by a couple of percentage points. Improving system efficiency, however, has proven to reduce energy consumption by 20-50%. A barrier facing any new DOE program is that most industrial facilities are very focused on production and much less focused on energy consumption.
If your focus is on production, capital budgets, maintenance expenses, product quality, and other more easily measured parameters, improving system efficiency might have benefits you have overlooked. To illustrate that point, let us take a look at a factory that decided to have a Kaeser Air Demand Analysis (ADA) completed before purchasing a new compressor. The ADA found that the factory had the capability to make 2,573 cfm of air at a pressure of 125 psig. The peak demand was 2,146 cfm, which cost the factory $194,328 annually for power to produce. (Pictured, Kaeser's magnetic drain prevents loss of compressed air.)
What the ADA also identified was that productive uses of compressed air totaled only 787 cfm and non-productive uses (leaks, personal cooling, etc.) totaled 1,359 cfm. Eliminating the non-productive use of compressed air could reduce the annual power bill to $71,318, saving over $123,000 per year. Additionally, the factory was using natural gas to heat water for a process. By switching from air-cooled compressors to water-cooled compressors and using the compressors to preheat the water, the factory could offset a large part of the remaining power bill. However, there is more to the story than just saving energy.
…Save Your Capital Budget
Consider that it required a 300 hp compressor to make the 1,359 cfm that eventually just vented to atmosphere without doing any work. Someone had to make a request for capital to purchase that compressor. Someone had to approve the request. And that represented a $65,000 capital purchase that did not need to be made. The factory provided data that showed they spent an average of just over $7,000 per year to maintain that compressor over the last seven years for a total cost of about $115,000. That money could have been used for production equipment. A Kaeser Air Demand Analysis can help you determine whether you need to make that capital purchase.
…What’s the Cost in Sales Dollars?
Another way to look at the cost of an inefficient system is to look at the amount of sales required to support it. In the above example, the factory was operating at a 15% net. The cost of purchasing and maintaining equipment that was doing no useful work was the equivalent of the profit on over three-quarters of a million dollars in sales.
Worse still was the ongoing inefficiency of the compressed air system. By optimizing the controls, eliminating non-productive uses and recovering the heat, the factory was able to reduce overall energy use by $150,000 per year. At their margins, they had to ship $1 million of product per year just to pay for power they did not need to use. Conversely, operating their compressed air system efficiently was like adding a million dollar account to their business. (Shown here, rotary screw compressor is tank-mounted, with space-saving design that offers an extremely small footprint.)
At 6 cents per kWh, with a 15% margin, it takes about a quarter of a million dollars in sales to pay for the energy to run a 100 hp compressor. That does not count initial cost or maintenance.
…Land a Million Dollar Account
Not every compressed air system runs as inefficiently as the one in the example above. The fact is, however, that most systems can be run more efficiently than they are running now. The first step in finding out how much you can save is to have Kaeser perform an Air Demand Analysis. Kaeser’s professionals will establish an operational baseline of your current compressed air equipment and a thorough report outlining potential savings. If you are starting a green-field operation or replacing an entire compressor room, Kaeser can provide P&I drawings, layout drawings (complete with piping), and a 3-D view. We can make certain that the layout is designed for future expansion, if that is in your plans.
…Keep That Million Dollar Account
One of the biggest problems with most efficiency improvement programs is that they only look at a snapshot of your operating conditions. With a Kaeser ADA, you are provided with a plan for efficient operation through a wide range of operating conditions, keeping your energy content per unit of production at its optimum. Kaeser can provide controls that allow you to continuously monitor the dynamics of your compressed air system. Without that kind of information, even the best system may run inefficiently; with it, you can land and keep that million dollar account.