General
Motors has expanded its GE Proficy
software solution to control lighting and other big energy consuming equipment
in its assembly plants, saving energy costs and considerably reducing its
carbon footprint. With a few million square feet of floor space, General Motors
realized that if they tied the lights (except for security lighting) to the
schedule of the conveyor, they could reduce energy consumption in the plant.
Proficy CIMPLICITY software from GE
Intelligent Platforms controls the conveyors in the plant, so GM managers
approved an application based on CIMPLICITY that schedules the lights to
coincide with conveyor operation. And it also led to other discoveries of
potential energy savings.
"Everything in a vehicle assembly plant is
tied to the conveyor," says Mike Durak, global information technology manager
for General Motors. "A hidden benefit was that once we scheduled the conveyor
we had a good view into what the plant was doing, so we were able to schedule
the on and off of big energy consumers in the plant like air supply houses on
the roof, ovens in the paint shop, lighting, water and compressed air
generators."
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"The biggest enabler for General Motors is that they were already using CIMPLICITY not only as a centralized HMI/SCADA system and production tracking/scheduling but also for monitoring and controlling their lighting and equipment as well," says Gimmi Filice, HMI/SCADA product manager for GE Intelligent Platforms. "Essentially they were able to tie these two systems together."
Filice says that generally, if customers start tracking and measuring energy usage, it provides a way to start looking at how to improve usage and develop a business case to reduce energy costs. From a general perspective, if you think about the facility and its manufacturing equipment, they are typically very different systems managed by different people, and they tend to be separated. One of the approaches companies need to look into is how to tie those systems together.
For General Motors, it worked out well because different groups within GM using the same software made it is easier to connect the pieces. They were able to achieve a fast payback and a five to seven times return on investment (ROI) very quickly. But Filice says the only way other companies can achieve improved results is to make it an objective from a manufacturing perspective.
"GM was already doing lighting control through CIMPLICITY, even though different groups were managing the lighting versus managing the manufacturing facility," says Filice. "They were able to say a euro ~we know the production schedule, when this line shuts down.' They were able to get the two systems to talk together and automatically shut off the power for both the lighting and production equipment."
He adds that connectivity to systems or individual pieces of equipment is very important. HVAC systems, for example, often use a BACnet protocol within the facility management system. Depending on the technology implementation, a product like CIMPLICITY may be able to talk over BACnet or another protocol to get information directly from the building control unit.
"Our goal is to work one-on-one with customers because a lot comes from the companies we are working with in terms of their goals," says Filice. "More companies do have energy goals in place. It's a matter of understanding those goals and figuring the challenges in terms of usage. Many companies don't know the details about usage, so a good first step is understanding where energy is being consumed."
Employees at GM are not affected by the automatic shut off of lighting and equipment. From the lighting perspective, lights are turned on two or three minutes before employees arrive at their workstation. The general building lighting goes on a few minutes earlier.
"We've also scheduled different turn on/shut offs on weekends," says Durak. "For instance, ovens in the paint shop need two hours to warm up so we need to take that into account when we turn them off. Therefore, we have different times for end of shift, weekends, extended long production, lunch and end of day, just to name a few."
The paint shop in automotive assembly is a significant energy consumer, because in order to make sure that the car's paint does not contain dust or other contaminates in the final product, it is important to have the optimum air quality and temperature. Proficy CIMPLICITY is used by General Motors to monitor the paint shop environmental conditions alerting the paint shop staff when process circumstances begin to trend out of acceptable ranges.
With its less than six month payback and low cost to implement, the solution is now rolling out to 20 plants within the GM family. Example annual savings versus one-time implementation costs at individual plants include:
- For weld water pumps/cooling tower/fans, chilled water and exhaust fans, annual savings 7 times greater
- For hydraulic pumps, ovens, weld water pumps/cooling towers/fans, annual savings 4 times greater
- HVAC and line lighting savings are 5 times greater
- Ventilation, line lighting, air supply/exhaust savings are 5 times greater
