Energy cost reduction through load balancing and shedding

Overcoming power factor degradations, higher energy costs and greater carbon dioxide emissions when controllers fire in phase angle.

03/17/2009


Power factor is an important aspect that drives up energy costs and therefore must be considered by operations and control engineers. This issue is particularly important when SCR (silicon controlled rectifier) power controllers are firing in phase angle.

Also read about energy management

Energy Management: First Steps Toward Greater Efficiency

Most utility companies apply a surcharge when the power factor goes below 0.9 (or 90%). In one year’s time, a power factor below this rate can translate to thousands or even tens of thousands of dollars, depending on the size of the installation.
To better understand how this can affect your energy costs , consider this scenario: The demand charge represents the cost per kW multiplied by the greatest 15-minute demand reached in KW during the month for which a power bill is rendered. However, the demand is subject to power factor adjustment. Utility companies reserve the right to measure such power factor at any time. Should measurements indicate that the average power factor is less than 90%; the adjusted demand will be the demand as recorded by the demand meter multiplied by 90% and divided by the percent power factor. For example with the greatest demand at 500kW and a power factor at 0.7, the demand charge would be increased by 28%. At $9.72/kW, that’s a $17,000 penalty a year with this relatively low demand example.
Adding in the issue of phase angle firing , the power factor decreases rapidly with output power. At 50% power, the power factor is only 0.7. At 25% power, the same power factor decreases even more at 0.5—resulting in even more penalties. In addition, phase angle firing creates all sorts of disturbances on the grid, such as harmonics, radio frequency interference, line losses, energy waste (KVAR) and transformer overheating. A manufacturer will eventually be forced to increase the capacity of its equipment to compensate for these disturbances, for example by installing active or passive systems such as costly capacitors.
Eurotherm has recently released a white paper describing these power issues in detail and how its 2 emissions.
Two key components are included in the PLM function: load balancing (or load sharing) and load shedding.Load balancing is a strategy of equally distributing power of different loads to obtain an overall power consumption as stable and balanced as possible thus eliminating peaks of power. This is in contrast to a random firing system. For example, each zone controlled by an EPower SCR controller, is defined by an output power, cycle time, and a maximum power (max capacity), which can be pictured as a rectangle. Rather than letting these rectangles pile up randomly, the EPower controller is said to uniformly distribute them, thereby ensuring that at any given moment the overall power is as stable and balanced as possible.
It is important to understand that the predictive load management function does not change the output power but rather balances and shifts the power evenly hereby eliminating any sort of disturbance. The result is optimum load management through intelligent load balancing and load sharing, a strategy that will eliminate peaks and flicker and even out overall power usage.
To access the Eurotherm white paper, click here .
Learn more about

energy management techniques

.
– Edited by David Greenfield , editorial director
Control Engineering News Desk
Register here .





No comments
The Top Plant program honors outstanding manufacturing facilities in North America. View the 2015 Top Plant.
The Product of the Year program recognizes products newly released in the manufacturing industries.
The Engineering Leaders Under 40 program identifies and gives recognition to young engineers who...
Strategic outsourcing delivers efficiency; Sleeve bearing clearance; Causes of water hammer; Improve air quality; Maintenance safety; GAMS preview
World-class maintenance: The three keys to success - Deploy people, process and technology; 2016 Lubrication Guide; Why hydraulic systems get hot
Your leaks start here: Take a disciplined approach with your hydraulic system; U.S. presence at Hannover Messe a rousing success
Flexible offshore fire protection; Big Data's impact on operations; Bridging the skills gap; Identifying security risks
The digital oilfield: Utilizing Big Data can yield big savings; Virtualization a real solution; Tracking SIS performance
Getting to the bottom of subsea repairs: Older pipelines need more attention, and operators need a repair strategy; OTC preview; Offshore production difficult - and crucial
Applying network redundancy; Overcoming loop tuning challenges; PID control and networks
Putting COPS into context; Designing medium-voltage electrical systems; Planning and designing resilient, efficient data centers; The nine steps of designing generator fuel systems
Package boilers; Natural gas infrared heating; Thermal treasure; Standby generation; Natural gas supports green efforts

Annual Salary Survey

Before the calendar turned, 2016 already had the makings of a pivotal year for manufacturing, and for the world.

There were the big events for the year, including the United States as Partner Country at Hannover Messe in April and the 2016 International Manufacturing Technology Show in Chicago in September. There's also the matter of the U.S. presidential elections in November, which promise to shape policy in manufacturing for years to come.

But the year started with global economic turmoil, as a slowdown in Chinese manufacturing triggered a worldwide stock hiccup that sent values plummeting. The continued plunge in world oil prices has resulted in a slowdown in exploration and, by extension, the manufacture of exploration equipment.

Read more: 2015 Salary Survey

Maintenance and reliability tips and best practices from the maintenance and reliability coaches at Allied Reliability Group.
The One Voice for Manufacturing blog reports on federal public policy issues impacting the manufacturing sector. One Voice is a joint effort by the National Tooling and Machining...
The Society for Maintenance and Reliability Professionals an organization devoted...
Join this ongoing discussion of machine guarding topics, including solutions assessments, regulatory compliance, gap analysis...
IMS Research, recently acquired by IHS Inc., is a leading independent supplier of market research and consultancy to the global electronics industry.
Maintenance is not optional in manufacturing. It’s a profit center, driving productivity and uptime while reducing overall repair costs.
The Lachance on CMMS blog is about current maintenance topics. Blogger Paul Lachance is president and chief technology officer for Smartware Group.
This article collection contains several articles on the vital role that compressed air plays in manufacturing plants.
This article collection contains several articles on the Industrial Internet of Things (IIoT) and how it is transforming manufacturing.
This article collection contains several articles on strategic maintenance and understanding all the parts of your plant.
click me