Take The Risk Out Of Load Shedding

Energy costs are a major operational expense for most food manufacturers — but you’re not at the mercy of your utility bills. With an advanced energy management system, you can control your energy use so that your facility runs at optimal efficiency, you pay the lowest possible rates, and you can participate in incentive programs that pay you for unused kilowatts. This article is the last in a four-part series on the fundamentals of electrical load shedding.

There’s probably no bigger barrier to reaping the benefits of load shedding than the fear that if you start messing around with power loads, production will fall off, food will spoil or become contaminated, or other disasters will ensue. That’s why we advocate safe load shedding.

What is “safe”? Powerit’s definition: no unexpected impact on production or quality. With demand control, there is almost never an impact, period — our system is configured to shed loads only when it’s possible to do so without affecting production or product quality. Demand response, however, almost always requires some give and take involving an expected impact that you’ve decided is worth the payoff. Without careful, precise control, that payoff can vanish.

Automation is essential

To be safe, load shedding must include automated actions that limit opportunity for human error. The energy management system (EMS) must be integrated with other control systems and proven reliable — you don’t want your EMS to add an element of risk via down time. Other key safety factors:

  • Your load-shedding strategy must allow for modifications on the fly, to accommodate the fact that needs and circumstance can change often in manufacturing.
  • You need good data on system and facility performance, both to justify your investment and to continuously improve your operations.

Key system capabilities

What do you need in an EMS to ensure safe load shedding? Based on our extensive work with food manufacturers, we see the following features as key.

Embedded intelligence: You should be able to embed the intelligence of your human facility operators into the EMS. This means any curtailment actions the system takes will reflect the right priorities for your operation, circumstances, and equipment—they’ll just happen faster and more reliably than is possible with manual intervention.

Precise timing: The ability to time load shedding precisely is crucial to minimizing impact on operations and maximizing savings. Load shedding should start not just at particular times of the day or the year, but at the exactly right moment.

Flexible rules: System rules must be flexible enough to integrate external factors — such as harvest variables, product and outdoor temperatures, and product combinations — that drive production situations.

Real-time response: The system must react instantly to meter data, sensor feedback, and other signals of changing conditions.

Closed-loop feedback from the process: Temperature, pressure, and humidity are all important feedback points that provide the information needed to allow real-time changes without endangering product and production rates.

Close coupling to rate data: All feedback and actions must relate to electricity billings, the ultimate measure of load-shedding performance. Your EMS must be adaptable to all the different ways you will be billed.

Finally, back to the human element: it’s important to provide performance data to everyone responsible for operations. The data, and the user interface that provides it, should be meaningful and encourage use of the EMS. That will provide positive reinforcement for the strategy and increase dedication to working for optimal operations.

Last week: What Loads Can Food Manufacturers Shed?

For more information, visit www.poweritsolutions.com.