Energy Efficiency

Energy Efficiency

Eduardo Schumann

November 2021

Published on the COM.PACK Magazine #52

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A lot is being talked about the COP26 and its attempt to reduce climate impact done by human beings. Among other initiatives, to reduce emissions we must reduce energy consumption. This cannot be achieved by governments alone. Every company should do a little bit to help.

As companies grow, they tend to use more energy creating an interesting challenge. A lot of initiatives were taken already to minimize consumption: usage of LED lights, better insulations, new electric motors, etc. However, more is still needed.

When visiting factories, it’s not uncommon to see improvement possibilities. Before talking about ways to reduce energy consumption, we need to understand how a typical utility company records electricity usage for billing. There are 2 important factors: peak demand and power supplied. Peak demand is the highest peak (kVA demand) during a 15 minutes interval (during a 30 day period there will be about 2.880 15 minutes intervals recorded). Power supplied is the amount of electricity used (normally measured in kWh). To reduce the billing costs it’s important to work on both of them.

There are a few good practices that can help reduce peak demand. The one I consider the most important is to avoid starting all the electric motors at the same time. Most of the motors do have a peak consumption when starting up and then they drop to the normal rate. If you slightly phase them apart, you can minimize very high peaks in consumption, which will impact in your billing. Another way of thing is that you have all your equipment connected to a generator (often the actual case) to set as a target. You cannot have the consumption going above the generator capacity (or your target).

Maintenance and electricity used (in KWH) go hand to hand. Poor maintenance tends to increase energy consumption. Improving maintenance has no bad side effects. If done right we get better asset utilization, better maintenance cost, and on top of it, we optimize energy consumption.

One of the most common conditions is poor lubrication practices. Not hard to understand. Poor lubrication on moving parts will require more energy (and will also lead to other maintenance issues). Sometimes is not just poor lubrication, often we can see it associated with bad cleaning (or the complete lack of it). In a visit years ago, operators were complaining about a palletizer with poor performance. When I look under it I was amazed. There was so much dirt on the moving parts that I was impressed the machine was still working (poorly but working). Cleaning and lubrication done right are very important.

One common but subtle issue is machine misalignment. Motors, couplings, pumps, gearboxes, etc need to be properly aligned not just to have the proper lifespan and minimize failures, but also to keep energy usage under control. The problem is, the level of necessary precision is very high. More than can be noticed by the naked eye. So, laser alignment is required for optimum results. You would be shocked to know a lot of installations, even nowadays, still do not use those tools, spending more energy, compromising the effectiveness and the lifetime of the equipment from day one. Motors heating up are often a result of misalignment and/or lubrication issues (if Amps go up, so does the energy consumption).

Improving OEE also saves energy. If we can do the same amount of production in less time, we can save energy. Preventing breakdowns improves OEE. This can be achieved through proper implementation of the available maintenance technologies, in special online monitoring, predictive maintenance, and enhancing reliability. Not exactly easy, but possible. I was able to get a very big line to run for more than a year without a single breakdown. Improving OEE does not have a downside. Do not accept lines with poor OEE performance, challenge it.

Another common issue is air leakages. A lot of unnecessary energy is used to keep air compressors running because of air leakages. Identifying and fixing those air leakages are not that hard using the correct tools (ultrasonic). With them, a weekly routine searching for those leakages can minimize energy costs. This is a kind of small investment with good payback.

On the production side, one thing that I see happening sometimes is idling equipment with no production or no reason for the equipment to be on. Just a waste of energy. There are some complicated solutions in the market to deal with that using algorithms and other technics. I don’t like very much those solutions, I rather rely on production and maintenance planning instead. Good plannings have collateral of giving more time for maintenance which can improve further uptime performance.

In big installations, induction generated in one motor may impact the energy flow of other equipment nearby. This can be seen through the harmonic wave in the electric line. Not so easy to fix, but there are solutions in the market (like Xeco Energy) that can reduce this effect, reducing the electricity consumption typically by something from 7 to 9%.

Reducing energy not only is good for the planet, but it also can save a lot of money for the companies if done properly. Are you willing to do your part?