Get a Hold on Power: 6 tips to manage your plant's energy footprint
Sustainability and energy management are more than green initiatives driven by social responsibilities — they have become economic imperatives. After one of manufacturing’s deepest downturns in recent history, companies are in survival mode and struggling to control expenses.
One common challenge among industrial plants is the level of awareness among employees about managing energy. Another challenge is that the employees on the plant floor do not have a lot of influence and control when it comes to making energy-management decisions. And a lack of collaboration between corporate engineering and plant engineering groups makes the process very slow.
Solicit worker feedback with a “watt watcher” program, inviting employees to submit ideas about how to reduce the plant’s consumption of electricity and fuel. Establish teams to ensure its success, establishing roles and responsibilities to ensure the corporate goals are well communicated, and share best practices across different departments.
It’s important to understand that energy management and asset management can work together: maintenance can record energy consumption data while scheduling maintenance activities.
1. Understand your energy costs.
Energy management is not just about tracking energy consumption through utility bills but also about how effective companies are when it comes to considering energy in operational decision-making. Start with a baseline plant energy assessment. An experienced energy assessor can identify many savings measures. Energy-awareness workshops also provide measuring and managing best practices, identifying energy improvement opportunities and strategies.
2. Compare yourself.
Once the baseline data on current energy consumption has been determined and reduction targets are established, effective measuring and managing of energy management performance is necessary. This enables companies to benchmark themselves internally as well as externally against industry standards. Therefore, management can continuously monitor and measure its success and make future decisions on scaling the program to other areas or plants within the enterprise.
3. Understand when energy is used.
An effective energy strategy takes into account different production contexts, such as production volume, shift, crew, uptime/downtimes and major waste events (like leaks). Energy management tools, such as power quality/energy meters (see page 14) and historian databases, help companies to automatically collect energy data and provide the decision makers with real-time insight into the energy processes. It allows companies to collect critical energy information and allows them to drill down to data per production line, plant or product. This information is critical in deciding how energy is used. Dashboards and reports clearly define consumption patterns, identify peaks, valleys, ramp-ups, ramp-downs, peak demand and load duration curves.
Armed with this data, it is easy to develop target settings to drive the right behavior on the shop floor. The energy data allows for forecasting an energy budget based on projected production demand and also provides a mechanism to validate energy balances and invoices.
4. Understand where energy is used.
A critical feature of an energy-management program is an annual energy audit of all operational systems, including the plant’s insulation, steam traps and lighting. As a result of these audits, many plant employees could participate in energy efficiency ideas, large and small, for management consideration.
Energy-saving measures fall into two categories:
- capital projects, such as heat recovery from boiler flue gas, variable-speed drives (VSDs), compressor controls, installing high-efficiency motors; and
- no-cost and low-cost measures that usually require continuous attention and the involvement of plant management, such as turning off pumps or lights when not in use, boiler combustion tune-up, maintenance of air filters, insulation, steam traps, and fixing air and steam leaks.
5. Eliminate waste and maximize efficiency.
The difference between eliminating waste and maximizing efficiency is as follows: leaving lights on when not required or having equipment idling while not in production can be seen as waste while putting dimmers and timers tied to production schedules or scheduling high-energy equipment to run at non-peak times are examples of efficiency.
• Thermal Energy: It has been suggested that, on average, plants with significant thermal loads, including steam, process furnaces and building heating, can save about 20 percent of fuel costs with a concerted energy program. This figure includes both capital and operating measures. Examples include heat recover systems from the boiler stack or installing reverse-osmosis water feed systems that demineralize intake water (reducing the need for continuous blow-down).
• Electricity: The potential saving of electrical energy is somewhat less than that of thermal energy. It’s estimated about 10 percent of total electrical consumption can be saved mainly through motor improvements, such as VSDs, fans, pumps and compressors. Other measures include power factor correction, automatic control of building HVAC, lighting improvements and air-compressor system improvements.
• Water: For most industrial plants, water cost is a minor component of the total utility bill. Potential savings are around 20 to 50 percent.
Installing gas, steam, air or electricity meters together with the implementation of a management reporting system can save five to 20 percent of energy. In most cases, this type of project only works if the management imperative and training of personnel go along with the metering system. Energy-meter data and asset-condition data can be used together to schedule maintenance activities. For example, if a compressor is using more energy than it’s rated for, it can be flagged for a scheduled maintenance.
Plant production scheduling, with the availability of real-time and historical energy data, can be used to lower costs by taking advantage of lower tariff rates while optimizing processes to be more energy efficient.
Statistical process control software enables companies to establish limits and alerts management when the processes are out of control limits. Investing in analytics, dashboards, and alert management provides the right energy data to the right person at the right time to enable decision-making.
6. Optimize energy supplies.
Issues like voltage sag, swells, harmonics, power factor, outages, and harmonics are all conditions that can affect equipment reliability. There are a number of conditions ranging from lightning, grid switching, unbalanced loads, etc. Correcting these conditions can greatly increase equipment reliability and production, thereby maximizing capacity and reducing energy consumption.
Consultants provide value through plant audits, helping executives to understand the gaps in energy management process and also provide some critical recommendations on the steps required to make a plant more energy efficient.
Operating facilities for renewable energy sources, such as solar, wind, landfill gas and geothermal, are all viable solutions to be investigated. Ontario OPA has introduced a program (FIT-Feed in tariff) for industry that provides a 20-year contract that pays up to $0.81 per KW of energy produced, making solar and wind generation excellent business opportunities.
Ivan Romanow is director of sales with Gescan Ontario. For more information, visit www.gescanontario.com. This was previously published in PEM’s July 2010 issue.