Watson, "If lighting represents only 1-2% of the utility costs of complex industrial plants, why are we always hearing and reading about how to cut your utility costs with lighting projects? Why isn't our profession focusing on the big opportunities, the other 98%?
Watson: When we trot into a complex industrial facility filled with production equipment, boilers, chillers, pumps, HVAC equipment, cooling towers, air compressors and more to try to help the owner reduce their energy costs, lighting really isn’t the first thing that comes to my mind.
Holmes: I agree Watson. We always prioritize our time; we start with the systems and equipment that are the largest energy users and work our way down to the smallest ones. We look at no-cost and low-cost actions to create the greatest savings at the least cost with the quickest payback.
We normally look at controlling the lighting so that it is on where and when it is needed and off where it is not. That may have a quick payback but I can’t remember ever considering spending capital money to replace adequate lighting.
What percent of the utility bill would you think is for lighting in a typical plant, Watson?
Watson: I did some research and found a great article on ESource titled “Energy Costs in Manufacturing Facilities”. It included five pie charts showing Manufacturing End-Use Energy Consumption by Subsector including Petroleum and Coal, Chemicals, Paper, Primary Metals and Food.
Lighting was only between 1-2% of all of the energy consumed in all of the different types of manufacturing facilities.
There was a note on the chart that said, “In general, process heating, drivepower, conventional boiler use, and cogeneration consume the most energy in manufacturing facilities.” The note didn’t mention lighting.
Holmes: Did you find anything else?
Watson: I found an article in Sustainable Plant from March of 2013 by David McDougall titled “The Top Five Energy Efficiency Measures for Industrial Businesses”.
Holmes: Where did lighting projects fit in?
Watson: Lighting wasn’t mentioned. The top five included: Identification of Contributors to Peak Demand, Weekend Energy Use, Weekend Set-Backs, Start-Up Spikes and Compressed Air Systems. Sounds very much like the things that you look at and emphasize. I would guess that David has quite a bit of on-site experience on the floor in plants actually saving energy.
One really interesting point he made was that Peak Demand factors were impossible to determine simply from looking at utility bills. He said that Real Time data is required and can be used insure that high-energy-demand activity doesn’t coincide with incidental loads that can be shifted or eliminated.
Holmes: We have used monitored data to do the same thing in nearly every project where facilities were paying significant peak demand charges; typically 40% of the total electric bill in the Midwest. We have a blog coming up fairly soon addressing Peak Demand and Demand Management products on the market. Our techniques are similar to the ones David is advocating and we will talk about them in that blog.
Back to lighting, Watson. In spite of the articles you found showing lighting to be a non-factor in most industrial plants, why do you think it is such a hot topic?
Watson: I would guess it is because a lot of people are making a lot of money designing and selling new lights to industrial plants and it seems easy to understand. I doubt there are many energy professionals with the skills and experience to go into complex plants and help them make their process systems, air compressors or chillers more efficient.
Holmes: I think you’ve hit it on the head again. When it comes to the really complex systems, most efforts are focused on selling new equipment under the guise of saving energy rather than tuning up what they already have. Another example of what’s good for the energy professional may not be the best solution for the owner.
I published an article last year titled “Are New Light Bulbs Really a No-Brainer”. It was kind of a tongue in cheek look at the dumbing down of the energy profession. In it I said,
“Everyone can understand a light; that’s a “no brainer”. Nobody is going to ask me about the part load efficiency of the chillers or measuring the boiler stack temperature and adjusting the oxygen trim, or using outdoor air for free cooling depending on the difference between the outdoor and indoor enthalpy. But light bulbs, now there is a great opportunity for savings. Let’s put in energy efficient lights.”
Watson: Everyone seems to be looking for simple answers for complex problems. What’s the solution?
Holmes: I must be beginning to sound like a broken record. We need more highly trained professionals using valid scientific methods based on actual data (and fewer light bulb salesmen).
Watson: My common scents tells me that when one of the smallest energy users in an industrial plant is getting so much attention and incentive money, something is wrong. Apparently many in this field have yet to understand where the real opportunity is, what you have told me so many times - People are the Key; Technology is Only a Tool.
Tell us about your experiences, both good and bad with energy professionals, what has worked and what hasn’t. Send us your comments, thoughts and suggestions on how to improve our profession so we can all continue to learn from each other. Thanks – Holmes & Watson.