Electrical and power systems are evolving and are continuing to become more efficient and sustainable, but challenges do persist.
Respondents
- Ken Crawford, senior director of automation, Weidmuller USA, Richmond, Va.
- Scott Dowell, senior vice president and general manager, industrial and CIG, Wesco, Pittsburgh
- Marc Elliott, marketing director, Eaton, Wilsonville, Ore.
- Zack Mitchell, CHST, GSP, assistant corporate safety manager, Stellar, Jacksonville, Fla.
Question: What are the key factors influencing electrical system efficiency?
Scott Dowell: The two most significant factors are the age of the manufacturing equipment and the maintenance of it. With aging systems in place, it’s critical to understand the current power load but also what is downstream and how it has changed over time. Often, the system in place was not designed for its current use. Digging into the scheduled maintenance program and if it has been followed will also shed light on efficiency issues.
Aside from the electrical systems themselves, the quality of the power being provided is also a significant factor. As manufacturers look to achieve their sustainability benchmarks, many are also finding the quality of renewable sources lacking as they simply can’t get enough to power the plant. This is a big part of the reason why organizations will put power conditioners on equipment. This approach hits more technical equipment downstream, which provides better and cleaner power.
More electrical devices are deployed on the factory floor than ever before. Products like ac drives and LED lighting create non-linear fluctuations in power quality that can be damaging to an organization’s power distribution network. To maximize electrical system efficiency, manufacturers should consider putting systems in place that can monitor, measure, and track how the system is performing. Cleaner and more consistent electricity yields greater uptime and higher quality production.
Question: How does power factor correction impact overall system efficiency?
Ken Crawford: Power factor results from the phase difference between the voltage and the current in an ac grid. It is also a metric that shows how efficiently the assets are used in the electrical grid. The energy within an electrical system is comprised of:
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Real power, typically measured in kW – represents the actual power consumed by devices, or, in other words, the part of current and voltage that are in phase, producing energy
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Reactive power, measured in kVAR (kilovolt-amperes reactive) – represents the part of current and voltage that is out of phase and cannot be used by the devices.
Real power and reactive power are the components of apparent power. Power factor is the ratio of real power to apparent power and can range from 0 to 1, where 1 represents that the current is in phase with voltage, and 100% of the power received from the electrical grid is used by the devices. If the electrical load is more inductive, you will likely experience a lagging of the current in relation to the voltage. It leads to a power factor going away from 1 (typical values can reach 0.95).
The lower the power factor, the more current is required from the grid to deliver equivalent real power to electrical assets. Power factor correction is implemented to shift an electrical system’s power factor as close to 1 as possible. When this is achieved, reactive power is minimized, reducing waste. Ultimately, it increases the efficiency of electrical assets, allowing less current to flow through the grid.
Question: What technologies or strategies can be employed to improve the efficiency of power generation from renewable sources?
Scott Dowell: Despite the interest from consumers and manufacturers alike to capitalize on greener energy solutions, unfortunately, we aren’t yet at a place where manufacturers can leverage 100% of their power needs from renewables. Bear in mind that renewable generation at a scale required to power a manufacturing facility occupies significant space. Many plants are either in a geography where wind and solar aren’t able to generate enough energy or the demand is too far away from the available power source. As such, there needs to be a blend of traditional and green power sources if the plant is to benefit from consistent power quality. This diversified approach has driven some manufacturers to get creative and employ localized renewable sources such as installing rooftop solar panels on their plants or leveraging microgrids with battery storage.
While still in the early stages, we expect more manufacturers to deploy these strategies as they look to maintain control over the quality of their energy sources and self-contain. This will be critical as they face times of increased demand and need to carefully manage the continuity of the supply, instead of relying solely on the utility for efficient and reliable power. Renewables have put the manufacturer in the driver’s seat to manage the efficiency of their power generation from various sources.
Question: What are some best practices to optimize the efficiency of electrical motors in industrial applications?
Scott Dowell: From an efficiency standpoint, there are things manufacturers can do with older technology and emerging innovations to optimize electrical motors. The goal is to get the right systems in place in front of the motor to manage and control as much as possible. Drivers, controls and power conditioning are all tried and true elements that help keep power lines as clean as possible. Cooling and climate-controlled systems also are proven tools to ensure motors don’t get too hot or too overused. Newer capabilities, such as sensors, provide the ability to report in real-time and offer information on exactly what a motor is doing and how it is performing. Coupled with a software application, the sensor sends a signal flagging any issues and coupled with data analytics, enables modifications to be made. In the future, artificial intelligence (AI) may also play a role by helping to anticipate problems before they start.
Question: How do smart grids contribute to enhancing overall system efficiency, and what challenges do they present?
Ken Crawford: Smart grids contribute to enhancing overall system efficiency by limiting power usage to unused or unnecessary items. Think of a room in a building that has southern facing windows. During the morning and evening there will be minimal light getting in the room, however during the middle of the day there will be maximum sunlight in the room. An ambient light monitor could be used to shut off some, if not all, of the lights in the room during this time leading to energy savings.
The challenge systems like this create are they create extra failure points. In this case, instead of having a light switch and bulbs that could be burnt out or bad, there is now the additional ambient light sensor as well as the monitoring system that could cause a fault.
Question: How can energy storage systems improve overall system efficiency?
Ken Crawford: Energy storage systems like batteries or capacitors improve system efficiency in two main ways. The first is energy storage, an example of this would be a solar panel array. During the day light is generating power that can be used immediately, but if it isn’t being used it makes sense to store the energy for later use at night when the sun isn’t shining on the panel to create usable power. This could also be used for a normal power generation source, gas generator or the like. When a powerplant is running it is always going to use fuel whether the maximum available load is available or not. Storing this energy would allow it to be used later without having to burn more fuel.
The second way is by helping against peak demand. An example of this would be air conditioning in the summer. During the daylight hours, it is going to be hotter out and more people will have their air conditioning on. During nighttime, it cools down meaning the air conditioners aren’t running as much. Power storage systems can store excess unused energy so it is available to use during peak hours of the day.
Question: How can predictive maintenance and advanced monitoring systems enhance the efficiency of power systems?
Scott Dowell: Anticipating and addressing problems before they become an issue can drastically improve the efficiency of power systems. This capability will become increasingly important as power systems become “smart” and microchip driven. Historically, these systems were more like one-dimensional machines that simply ran until they could not perform any longer. Today, however, it’s more akin to flying a plane with many moving parts, each piece dependent on the other, and any one failure can be catastrophic.
Individual components do more than ever (and often more than ever designed to) which requires a plant manager to make sure they are on top of the ins and outs and working as intended. Previously, if a component overheated and something tripped it might take a bit to identify where and what exactly went wrong. But with predictive maintenance and monitoring technologies, manufacturers can control the temperature from the start and avoid overheating. That investment in new technologies and capabilities has resulted in a greater focus on executing a predictive maintenance schedule as it ensures the factory can get the most out of its power equipment and its new capabilities.
Marc Elliott: First, it’s important to define efficiency. Is it about using less electricity, avoiding downtime or making power quality improvements? Advanced monitoring systems can enable continuous monitoring to trend what’s going on over time as well as real-time alerts to act on. Leveraging both is likely the most effective way to enhance efficiency and predict (and avert) problems. Condition monitoring systems allow organizations to make smarter maintenance decisions based on actual equipment and environmental data. These capabilities help support safer working conditions and ease compliance with the NFPA 70B, which recently became a standard for electrical maintenance.
Question: How do different energy sources impact the sustainability of power generation?
Scott Dowell: The continuous flow of energy sources into a facility is critical for uptime and reliability, and today most manufacturers need a mix of renewable and nonrenewable to make that a reality. It’s not yet commonplace for a factory to run 100% on renewables as the quality of the power source continues to be a concern for many. The best approach is diversifying power sources from traditional energy and renewables. This strategy is leading many manufacturers to own their source of renewables, either on site or elsewhere, as it can work in tandem with utility sources to help achieve their reliability, efficiency, and sustainability goals.
Question: What role does energy storage systems play in enhancing the sustainability of power generation from intermittent renewable sources?
Ken Crawford: Energy storage systems are utilized to capture and store the excess energy produced during peak periods of renewable generation. The stored energy can be used to compensate for intermittent energy production (no or low wind for wind farms, cloudy or nighttime for PV) and maintain a consistent supply of power for the grid even during periods of low generation. Energy storage systems promote grid stability, as they are an excellent mechanism to counteract energy fluctuations with speed and reliability. This reduces strain on the grid while making it more reliable and efficient.
Marc Elliott: Energy storage systems enable curtailment and steady power from intermittent resources — providing flexibility, resilience and reducing costs. The electrical system is the backbone of industrial operations, and energy storage provides a creative approach and vital tool to keep the power on. Consider all the energy storage levers at the ready for industrials—whether it’s your uninterruptible power supplies (UPS), capacitor bank, electric vehicle (EV) fleet, battery storage and more. At Eaton Experience Centers, which provide hands-on training environments, we’ve incorporated many types of energy storage into industrial power systems, demonstrating how to stretch energy infrastructure.
Question: How can microgrids contribute to sustainable power generation, especially in remote or underserved areas?
Marc Elliott: Microgrids balance where, when and how electricity is consumed—managing all onsite resources, including solar and wind. This can be especially important for manufacturing facilities in remote areas, where power quality issues are common. Further, microgrids provide a means to reduce dependence on the local grid and diesel generators by optimizing power from renewables. We recently helped AEP Ohio develop the first microgrid for the City of Columbus for critical water infrastructure. The solar-plus-storage microgrid demonstrates how climate-friendly technologies can be applied to modernize critical infrastructure, while improving the environment and the bottom line.
Question: How can advancements in energy efficiency technologies complement sustainable power generation efforts?
Scott Dowell: The biggest benefit it provides is the ability to consume less power overall. Combining energy efficiency technologies with renewable sources enables the factory to do things more capably while still maintaining the onsite needs for production that are already occurring. Sustainable power generation, in the form of renewable energy, doesn’t provide a consistent and large enough power source to run a manufacturing plant on its own. Mitigating the power consumption on site provides manufacturers the opportunity to capitalize on sustainable sources, but better manage how that power source is utilized.
For example, when it comes to solar power, organizations may run out of energy before the manufacturing process is complete and the battery has been recharged. But if you are able to run more efficiently from the outset you can consume less power overall which provides greater flexibility in regard to the source of energy used. By working in concert to reduce overall power consumption, the organization can put back that energy into the grid and pay forward that energy source to others.
