The deregulated electric utility market has planners sharpening their pencils when it comes to new construction expenditures. But as the demand for power generation continues to grow, companies are seeking ways to cut costs and maximize their return on investment (ROI).

Consumers Energy (Jackson, Mississippi) is putting to good use a substation building strategy it began developing more than 40 years ago—pre-engineered standard structure materials. Available throughout the industry from Erecticon and V&S Schuler Engineering (Canton, Ohio), the modular design approach reduces design and construction cost significantly, as well as gives construction crews total flexibility in the final stages of field installation.

Standardized Materials
Consumers Energy has just finished a 138- to 46-kV bulk power substation—the Grodi Road Substation—near Monroe, Michigan, and has two more on the drawing board, all patterned (literally) after the three it built last year using the Erecticon standardized design.

“It’s a giant erector set,” says Michael O’Connell, Consumers Energy senior technician. “We use a small list of parts to configure an almost unlimited variety of substation designs, ranging from small distribution stations to large transmission switching stations.”

Pre-engineered Erecticon trusses and columns are pre-welded, eliminating bolting of lacing members in the field. Boltholes in the trusses, plates, brackets and fixtures are punched on 3-inch centers, creating exact fit and interchangeability.

“By placing the holes every 3 inches, all the angles are standardized. Beams and columns can be raised or lowered to any height, creating structural flexibility and adaptability,” reports Greg Shaheen, vice president of V&S Schuler, the manufacturer of the modular materials.

Reduced Lead Time
Consumers Energy and V&S Schuler Engineering have spent years finding ways to reduce the lead time for new substation construction. The number of standard “pieces” has been refined and consolidated to the point that the finished structures being constructed today are the strongest and most sensibly built. The number of drawings has been folded into five suites, compared to the more than 50 required on most traditional substation projects. By using a “pick lists” built into the design program, engineers can generate a set of drawings in a fraction of the time it would take to start from scratch. What this translates into is major cost savings for the utility.

Consumers Energy also is expanding a substation that was built two years ago using Erecticon standards. All parts are 100% interchangeable, so “bolting on” a 20% expansion to a substation is no chore. Parts are salvageable and can be reused on future projects. Trusses, columns and angles are delivered to the jobsite pre-welded and hot-dip galvanized, which has proven cost effective for corrosion protection over the life of a substation.

From past experience, V&S Schuler has developed two types of prefabricated box girders for columns and trusses, which can be used interchangeably. The 3- by 3-inch chord angles allows construction crews to completely assembly sections on the ground before erection.

Pieces Fit Together
Two new Consumers Energy substations still on the drawing board are being designed for Clair, Michigan, and Battle Creek, Michigan. In both cases, steel structures do not need to be detailed again, and minor changes are simple with the interchangeable capabilities of using Erecticon structural parts. No two substations are exactly alike. Once the unit is built, crews can change the height of a truss to attach a recloser mounting or move a column to accommodate switches and other electric components. Field changes, which traditionally are labor-intensive, are as simple as unbolting and bolting structures to fit the situation.

The benefits of using modular materials were underlined in a recent tubular steel project. Holes had to be drilled in the field, and an additional brace had to be welded in place. This all took a lot of extra time after the main construction crew had left the project. Compare that to using modular materials, which have holes every 3 inches and cross support holes every 2 feet.

Conclusion
For more than 40 years, V&S Schuler Engineering has worked with Consumer’s Energy to design and construct more cost- effective substations. The utility’s lead time has been reduced by months, simply by standardizing substation structures and the designs that go into building a new facility. As Consumers Energy’s Michael O’Connell says, “It’s like putting an erector set together. We can use the same structural materials to build stations anyway we need to without reinventing the wheel.”