T&D

modular substations: breaking the industry mold

Issue 5 and Volume 82.

Timothy P. Adams, assistant associate editor and online editor

With the utility industry in the middle of a market transformation, reliability and cost-effectiveness are two major factors affecting the future of utility transmission design and implementation. Some vendors contend that the traditional substation design approach is beginning to find its way to the industry back burner as customers increasingly place demands on utility improvements regarding transmission prices, aesthetics and reliability. In order to respond to their customers’ demands, utilities are exploring alternate methods to accomplish these goals.

One method that is fastly arising in the industry is the “modular substation” approach, according to industry experts interviewed in this story. A modular substation design consists of pre-assembled equipment installed on a structural base that is pre-wired and tested before shipping-by truck, train or cargo ship-to the new or existing worksite with only the appropriate connections left to be made onsite.

“Although modular substations have been around for quite some time, the utility industry is beginning to implement this method more often. The modular approach offers utilities many benefits when compared to the more traditional or standard approaches,” according to Richard Marking-Camuto, manager of systems integration for Cooper Power Systems.

Vendors contend that when comparing modular versus traditional substation design methods, most noticeably the cost-effectiveness is what stands out. They also stated that along with its cost-effectiveness, the modular design method also offers benefits in terms of resources, flexibility, reliability and maintenance, aesthetics and speed.

cool, calm and effective

Because of the overall industry downsizing and the additional financial constraints placed on utilities over the past few years, fewer in-house resources are available for project design, construction, implementation and maintenance. In addition, as the workforce numbers decrease within a company and the workload levels remain constant-if not increased-utilities are obligated to find solutions, which typically result in being located outside the company in the form of a consultant or a turnkey provider.

“In today’s market, the trend for utilities is to look at outside resources for a more standardized or turnkey design approach that allows the utility to use what resources they currently do have-from both a maintenance and an engineering standpoint,” said Richard Marking-Camuto.

As Bill Wood, CEO of San Isabel Electric in Pueblo, Colo., also confirmed, “Using our outside resources, we were not only able to achieve the design we wanted, but we also were able to erect the substation in the field in a matter of one day. What typically would have taken us a year to design and erect, using our own employees, took us a portion of that with modular design approach while allowing us, as a company, to focus our time and efforts on other projects.”

Since the modular substation approach requires the substation to be designed and built offsite, the flexibility of the design is also very important.

“We can use any type of equipment. People sometimes look at the modular designs already implemented and think that the equipment used is not their type of equipment, so the modular approach is not going to work for their project. What they fail to realize is that the modular design adapts to all types of equipment. The flexibility, along with the cost-savings and time-savings, in this approach is what makes the modular design so beneficial,” added Steve Adams, the director of service power technology and power systems for ABB’s North American headquarters.

Wood also said, “In our case, we were able to ship our metering system to the factory and have it mounted and housed on the panels within the modular substation. So, instead of having to add our equipment after design and installation, we were able to have it directly built into the project. It was just an additional benefit to an already well-defined project design.”

In addition to the flexibility of the modular substation approach, the ability to work in a controlled environment also benefits the project’s design in terms of reliability and maintenance. Constructing the substation in a temperature-controlled factory not only decreases the project’s labor costs, it affords the project the environment needed to work efficiently and effectively without any schedule delays or interruptions.

As stated by Marking-Camuto, “You’re generally using less expensive factory labor to do the interconnection wiring of the controls and power rather than field labor, which is significantly more expensive in most cases. Also, the ability to house the equipment and cable increases the reliability and maintenance of what is an already successful and reliable product since the parts are not exposed to the weather, rodents or any other element that might affect its dependability.”

Marking-Camuto also went on to say, “Since there is very little work to be done in the field using the modular approach, most of the work takes place in the factory. There we are able to test the equipment and system before it ever leaves our site to ensure its performance level. In addition, if there are any work order changes, it is a lot less expensive-and more reliable-to make the changes in the factory rather than in the field.”

In addition to building the substation in the factory, the controlled environment also removes you from Mother Nature’s wrath. Most of the time, construction crews in the field encounter weather that can affect schedules and working conditions, which ultimately affect how well and how fast the substation is constructed.

“We realized that labor costs and weather were major obstacles when designing and implementing a new substation. Throughout the summer months, we have weeks on end that record daily temperatures over 100 degrees. For this reason, we knew it would be beneficial to have the substation built in a factory rather than in the field. What would have taken us a number of weeks in the field to erect, took us one day with the modular approach,” said Wood.

easy on the eye & wallet

The aesthetic appeal is another factor utilities must consider when designing substations. As communities increase in population, space is becoming scarcer, especially for unappealing steel structures. Customers want the equipment to blend in as smoothly as possible, and although there is difficulty in making such a structure truly blend in, anything that can be done to help is an improvement.

“The low-profile design is an additional benefit to the modular substation approach. Having the controlled environment in which to work allows us the time needed to house the equipment. The cable and control wires are pulled through the trays and built directly into the skids. Therefore, the consumer is not visually overwhelmed with all of the cable and control wires needed to operate the substation. Everything is generally housed, thus it is inherently more appealing to the eye of our most important critic-the consumer,” added Adams.

In addition to the aesthetic appeal modular substations offer, time-savings and cost-savings are becoming more apparent as more modular designs are being constructed and implemented within the industry.

As Adams noted, “From the 46 modular substations we, at ABB, have designed and implemented, we’ve seen project delivery time-savings of 30 to 50 percent and an additional cost-savings anywhere from 5 to 10 percent when compared to traditional or standard substation methods.”

“Although project cost-savings are important when looking at the bottom line, utilities do not include in their final numbers the fact that the they are up and running sooner than expected, thus an earlier return on their investment is realized. Simply put, the modular substation starts earlier and finishes earlier; so the benefits are realized earlier,” commented Marking-Camuto.

Additionally, as engineering prices continue to increase and companies deal with meeting the bottom line, it is inevitable that alternative methods for substation design are being sought. As the experts interviewed in this story noted, through successful design, implementation, reliability and return on investments, the modular substation method is proving to be a reliable alternative in place of the more traditional approaches.

“For a utility, I have not found a reason as to why ‘not’ to use the modular approach for substation design, other than the fact that it is newer. It has proven both its reliability and its ability to save utilities time and money. Yet, there are those companies that still have their own construction crews and evaluate their own resources differently, but for the most part, and for most utilities, this is a viable method for substation design, construction and implementation and it will continue to grow in popularity as more companies realize the benefits,” Adams said.