Energy well spent: Cement manufacturer sees huge savings with automation strategy
March 25, 2014
By Mary Del
When Fabio Garcia moved to Canada to work for St. Marys Cement’s Bowmanville plant in 2003, he saw an opportunity to save the plant money — millions of dollars, in fact.
Coming from Brazil, where industry’s use of energy is very tight, the operations manager knew the plant could better manage its energy, which accounts for 35 per cent of its overall costs.
“It’s a huge impact on your cost,” Garcia says. “It was hard to understand, why would you not take care of that?”
But where would he start? Cement manufacturing is different than most industries in that it’s a 24-7, 365-days-a-year operation — and St. Marys Cement has been operating this way since 1912. Its Bowmanville plant, the largest cement plant in Canada, would have to undergo a paradigm shift if they were going to be successful in reducing energy consumption.
“The kiln takes 24 hours to heat, 24 hours to cool. It’s certainly not something that we would want to start and stop rapidly. So that means that all the ancillary processes that feed that system are generally ones that run 24-7, 365, and most cement plants operate with that mentality. Everything runs all of the time,” says Jason Schultz, the facility’s quality manager. “What we’re doing is looking at how we can take blocks of our process, control volumes of our process, and add in levels of complexity and control that give us the flexibility to operate some equipment at less than that 24-7 interval.”
Their success would hinge on gathering the information needed to make decisions, getting the right people in place to steer the charge, and implementing automation.
Putting a plan in motion
The plant began focusing on energy management in 2005. They started by gathering information about their energy costs to determine exactly how much they were spending. They went through their bills and found three occasions where there was missing metering data, and historical data was substituted on occasions where the plant had slowed down its operations and the costs shouldn’t have been that high. This simple process saved the plant $50,000.
The next step was to get people on board. In 2006, Garcia launched the Energy Management Conservation Committee, or E=MC2, with eight representatives from various departments within the facility. This group would be tasked with reviewing the entire operation and coming up with ideas to reduce energy consumption, and then implementing them. Today, the group, which meets every Tuesday to discuss ideas and review progress, has expanded to include 11 individuals from such departments as production, electrical, quality control, environmental, mechanical maintenance, HR and finance.
“If you get one representative for each department, the idea is, if I need to implement an energy initiative, that normally is going to involve operations, it’s going to involve [the] electrical department, it’s going to involve [the] mechanical department, it’s going to involve maybe the quarry. So I know that the spokesman for this department, that he’s part of the committee. He’s going to be the one that’s going to be the driver from his department to make this happen. So the ideas should be able to flow much faster,” says Garcia.
The next step was to go after the low-hanging fruit — initiatives they could implement themselves with little to no cost that would yield a great return on investment.
For example, they discovered a redundant fan while reviewing their operations. The team saw the opportunity to shut it down without impacting productivity — a step that saved the plant $100,000, or 1,500-kilowatt-hours of energy. Another discovery was an ineffective heating system in the quarry garage. The team installed ceiling fans to lower the temperature and improve heat distribution.
The group also focused on educating the workforce about energy management. Their approach was to teach employees how to conserve energy at home, with the hope that once they started seeing results, they would bring this mindset to work with them and help save the plant money, too.
Over the last eight years, the team has identified and acted on more than 223 separate energy efficiency initiatives, reduced electrical consumption by over 14.2 million kilowatt-hours, and avoided energy costs worth more than $3 million in the process.
Much of these savings, however, can be attributed to a system they created “from the ground up” that allows them to automate all of their energy initiatives and systems.
The automation factor
E=MC2 team member and plant systems administrator Peter Boorsma built an energy management dashboard, based on input from several team members, that manages energy usage in the plant, detailing exactly how much power is being used. Boorsma was able to do this without purchasing additional computers or control systems, but rather through utilizing their existing computers and control system infrastructure.
The main dashboard in the control room shows the plant’s power, the demand for the province of Ontario and the hourly electricity price. It also shows the plant’s five critical peaks, and what their contribution is to the five critical peaks for Ontario. There are screens in the control room that show the main dashboard, load shedding, kiln startup, calciner startup and raw mill startup.
Efficiency indicators, alarms and automatic shutdown were put in place throughout the plant to help employees better manage energy usage.
“We started out by going through a lot of our systems and looking at purge times — how long the system was running to empty out. And rather than just taking the safe approach and having systems run probably twice as long as necessary to completely purge the system, we actually timed it and staged the shutdown so that we didn’t have the equipment running any longer than necessary on various systems throughout the plant,” says Jim Storey, electrical maintenance manager and member of E=MC2.
There is a panel meter on the operator’s display in each process area that shows the pre-determined optimal operational energy consumption. The operators get visual indicators on their process control screens when systems are running less than optimal, empty or at low tonnages.
“If we have high energy consumption in areas, there will be alarms generated, or if the system is running empty and there’s an energy savings opportunity, alarms will come on so that we know we can go out and shut systems down when they’re not productive,” explains Storey.
“We’re basically taking a look at how the entire circuit needs to start, piece by piece, and organizing all equipment with frequencies and wait times between the different starts,” says Nick Papanicolaou, production manager and member of E=MC2. “It’s literally the click of one button to say, ‘I want this system to start up,’ and the automation in place starts up every piece of equipment in a proper sequence so that nothing will overload something else and it’s going to balance itself out. A lot of automation has been put in to allow our operators to be effective at running our process.”
The plant manages energy in terms of consumption and hourly pricing. They have set pricing alarms so that they’re notified when price points are going to change.
For example, explains Storey, “We can automatically start up dewatering systems in our quarry based on pricing. So if the level of the water in the quarry is above a certain level, we may have to pump, especially in the spring, continuously. But other times of the year we can pump when the price is less a certain amount, typically in the evenings and weekends. So it’s all automated.”
“There’s been dashboards built where we’ll get an alarm at noon that says ‘tonight your power prices could be very low in comparison to now,’” explains Papanicolaou. “That alarm will trigger the thought process amongst our group to say, ‘Is there something that’s running now that doesn’t need to? Do you have inventory in other areas that will allow you to stop it and run it tonight because it’s going to be more cost effective?’ So all of that is automated where we’re prompted to make those management-level decisions by the automation that’s in place.”
Automation also allows the team to co-ordinate load shedding.
“If we know that there’s going to be a critical peak for a certain day, then we can choose which equipment is going to shut down, we can choose the time at which it is going to shut down, and it will just happen,” says Boorsma. “We don’t have to send instructions to anybody. It will just happen.”
Automation allows the plant to effectively participate in the Ontario Power Authority’s demand response program — a program where companies get paid to reduce electricity consumption. By participating in DR3 — a contract-based program where participants are required to reduce loads when they are called upon — they have the opportunity to generate increased revenue provided they meet the contractual obligations. The plant has received $2.3 million back over the last two years just by participating in this program. (This is in addition to the more than $3 million in savings they’ve seen since their efforts began.)
“It’s a pretty elaborate amount of automation, but it’s working, and I think the results speak for themselves,” says Papanicolaou.
Going for excellence
Thanks to all of their efforts, the Bowmanville plant has received the Certification of Energy Excellence (CEE) from 360 Energy — a certification awarded to organizations using international best practices for sustainable energy management. They have also received ISO 50001 certification — the first to receive this designation in North America, they say. This specification lays out the requirements for establishing, implementing and improving an energy management system, and allows the plant to follow a systematic approach to achieving their energy goals.
“We have a world-class system, and certification can help validate that world-class system,” says Schultz.
“We rely and live and die on our systems, which means that we have to have procedures in place and standardized books for doing business, standardized principles for workers so that when Nick goes home and his expertise isn’t available to his team, that they’ve got procedures and policies and tools at their disposal to help them do this job so that they do it the same way that we’ve determined to be the best way,” explains Schultz. “And when we find better ways to do it, we have a system we can go back to and modify.”
Paradigm shift achieved
Nowadays, energy plays a big part in the decision-making process at St. Marys Cement’s Bowmanville plant.
“If we are going to shut down a kiln, because we do have to do maintenance on them, a big part of that decision is based on energy — peak times or a summer period of a heat wave,” says Storey. “We always are considering energy now in those decisions.
“We went from being a plant that had to worry about production and when would you get time to do maintenance, to being a plant that says, ‘Well, we need to produce a product, we have to do maintenance and we need to be considering the energy implications and cost,’” he adds.
The team members say that this paradigm shift, and the energy savings success the plant has seen, are all thanks to their committee-based approach, the group of people on the committee who thrive on the challenge of coming up with ideas and seeing them through and, of course, the automation to manage it all.
The team is proud of their accomplishments because they not only save the plant money — thanks to Garcia’s forward thinking from an early start — but they’re also helping the environment and, says Schultz, being “good corporate citizens” in the process.
This article originally appeared in the March/April 2014 issue of Manufacturing AUTOMATION.
- Lean and green: Use lean manufacturing principles to deliver green results
- Empowered: Automation puts you in control of your energy costs