What are the Costs of Compressed Air?
Why should you care about the cost of compressed air to power your pneumatics?
In my business, we solve problems. Maybe your problem today is that you need automation to assemble your product. Are you going to do a bunch of calculations to figure out if your specification should dictate if the machinery is driven with pneumatics, hydraulics or electro-mechanical, likely not?
What is more likely is that you will be stuck with the technology that best suits your particular need. I know you understand that none of the technologies are free beyond having to purchase the hardware, but I would like to give you some things to think about when you choose compressed air to power your equipment. This information is not meant to be a negative about pneumatics because you can often save money on the hardware that is relatively inexpensive and readily available versus many other available motion control technologies.
When most people think of compressed air, they think it’s the free service that comes out of the wall in my plant every 30 feet, in the form of a connection that’s for my use whenever I need it. In the real world there are costs to generating compressed air. Compression of air is one of the most inefficient processes and has only made a handful of innovations in the last 40 years. The process is still very inefficient, with most experts and studies putting the range of efficiency from electrical input power to compressed air output between 10% – 15%. This inefficiency is why most plants spend 30% of their power consumption on compressed air. Does this revelation spell the demise of compressed air? I say, NO… on the contrary, it seems that there’s a huge upside to working to increase the efficiency and lower the overall cost of our compressed air, or at least bring compressed air costs on par with the other technology’s input costs.
Just so I don’t bore you with all the details, I’ll site the outcome of one article that seems on par with much of the information you can find on compressed air cost. The November 2016 issue of Hydraulics & Pneumatics® magazine has an article titled Save Energy by Recycling Air. It concluded that the cost of air at the inlet is about $0.47/MCF and about $3.33/MCF at the outlet of 90 psi. FYI… MCF is 1000 cubic feet not 1,000,000. Why such a difference between the inlet and outlet costs? Simple, even at 100% efficiency you still need to compress free air around 7:1 to get to 90 psi. It is also important to point out that they priced electricity at $0.07/Kw-Hr. Even a small compressor may compress 100,000 cubic feet per day and cost you over $1,000 per month for air service.
So, I asked you why you should care about the costs of your compressed air to power your pneumatics. I contend that if you don’t control your pneumatic costs, your pneumatic costs will control your bottom line.