Energy Efficiency

Schneider Electric regularly hosts workshops to help clients understand energy — from how it's produced to how it's consumed. This blog series, A Beginners Guide to Electrical Engineering, focuses on highlights and topics of conversation from these sessions.

The last post challenged the traditional ways to supply the grid’s base load.  Now, it's time to focus on the demand side, asking the question: Is a facility's base load a 'fixed' cost or an overlooked opportunity for efficiency?  Mounting evidence points to the latter.

Base load is no longer a ‘fixed’ cost

In buildings, base load refers to the consumption of electricity, gas and water that is not correlated to productive activity. It’s the amount of resources that a facility consumes around the clock, even when no one is working. Historically, base load has been accepted as a ‘fixed’ cost, but savvy corporate energy mangers are finding that there’s actually a lot of waste that could be trimmed and turned into savings.

What’s changed?

The Internet of Things (IoT) will have connected 5.5 billion devices in buildings by 2020 and currently provides an average plant more than 8,000 data points. This gives facility managers more visibility than ever into individual site operations. 

Enhanced data management often reveals a host of hidden savings opportunities in manufacturing environments. In fact, base-load reduction can yield 5 percent or more in annual energy savings and GHG reductions through simple operational changes such as control adjustments or maintenance to address equipment wear-and-tear.

Corporate energy managers will often leverage results from these operational projects to win executive buy-in and funding for more capital-intensive projects such as retrofits and onsite renewables. This programmatic approach to efficiency has been proven to be an effective strategy to achieve even the most ambitious sustainability targets — e.g., 40+ percent energy savings and CO₂ reduction in 10 years.

Path to savings: Base-load reduction

As Weston Foods can attest, collecting real data through a comprehensive Resource Assessment offers the quickest path to savings. Once you have the data, here are three key steps for base-load analysis.

1. Analyze electricity, gas and water usage data against a measure of plant production (hourly is best, by shift or day if limited by available data)
2. Estimate the magnitude of your fixed/base load and calculate the annual cost of this energy
3. Investigate and understand the components of fixed load (i.e., specific loads)

Convenience vs. productivity

When assessing base load of manufacturing facilities, it’s important to make the distinction between operation (convenience) and productive operation. A facility may operate 24 hours per day, seven days per week, but how many of those hours is the plant operating at maximum capacity versus sitting idle? Which specific loads are on during non-working hours and are they truly necessary?

Just as a plant would not schedule large numbers of employees that sit idle during times of low productivity, or expect to consume raw materials during such times, energy and water consumption should be managed to the minimum required for safe and effective plant operations.

Case study: Removing base-load waste

To illustrate how base load can be reduced during both non-working and production hours, take a look at Schneider Electric’s own manufacturing facilities in North America.  The figure below shows a recent load profile of a U.S. plant where the typical peak load is 550 kilowatts (kW), shaded red, and the base load is 210 kW, shaded blue.

Like many manufacturing facilities, this site’s mission and occupant profile has changed multiple times since its construction in 1978. Its operation has also been impacted by advancements in building and process efficiency over the past four decades. The result was an electrical power distribution system that was significantly oversized for the present-day load, leading to transformer (no-load) losses of 78 kW.  In other words, 37 percent of base load that was presumed to be fixed cost was actually waste.

To right-size the system, technicians took two of the seven substations out of service and reconfigured the the busway (bus duct) to serve the entire plant load from one substation. These projects have a simple payback of less than one year.

By addressing this one issue, with little capital expense, the plant will reduce base load by 60kW for an annual savings of $47,000 and GHG reduction of 330 metric tons of CO₂ equivalent.  

Decreasing base load remains a sorely missed opportunity for efficiency savings that not only exist for most companies – but can be achieved without significant capital investment.

Looking to jumpstart your 2018 savings plan? Contact us to learn more about Resource Assessments.

Contributed by: Jacob Freeman, Paul Stiller and Walter Hendrix