Please excuse the headline. We’ve seen a few too many sales flyers this holiday season.
Variable speed drive (VSD) technology is a topic we talk about a lot. So much so, that sometimes we feel like we’re beating it into the ground. But because it’s so important, we’re going to cover VSD technology one more time this year – and then we promise, we won’t mention it again until 2013.
The value of VSD technology comes down to one universal truth: the simple economic model of matching supply to meet demand optimizes productivity and helps control costs. The same philosophy is true when considering compressed air production.
Even in facilities that run continuous, round-the-clock operations, there are likely cycles where lulls in production offer opportunities for energy savings. For example, there are 168 hours in a week and most compressed air systems only require anything near full capacity between 60 and 100 hours, or about half the time. When an air compressor runs at 100 percent to accommodate demand that represents only 50 percent of the compressor’s maximum output, then half of the energy required to power that compressor is immediately wasted. Variable speed drive air compressors continually and automatically vary the production and output of compressed air to meet fluctuating power requirements – here is an animation that illustrates the point.
We wouldn’t harp on the VSD issue so much if statistics compiled through compressed air system assessments and performance analysis didn’t show that the majority of air compressor applications are ideal for VSD. If you’ve proven through a system assessment that your facility’s air compressors fall in that 10 percent range, then feel free to quit reading.
If not, you need to know that compared to a fixed drive compressor, a variable speed drive compressor sized for the same end use requires on average 35 percent less power to operate. That results in extremely significant savings.
Here’s an example. A manufacturer is running a 200 horsepower air compressor 24 hours a day at 8 cents per kWh. At 8 cents per kWh, that air compressor costs $110,062 to operate every year, or more than $550,000 over five years. Switching to a VSD compressor could potentially save this facility $38,521 annually or $192,608 over five years.
When you combine these savings with the greater efficiency that is realized when you replace older equipment with newer, more efficient compressors, the return on investment is often realized within two years.
And, that’s just smart business.
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