Ford's focus on solar power
The Ford Motor Company worked with Michigan utility DTE Energy on the installation of the largest solar array in the state—the second largest in the U.S. Midwest—at Ford’s world headquarters in Dearborn, Michigan.
By Vicky Boyd
Henry Ford is often credited with being a leader in innovation and sustainability. Today, Ford Motor Co. continues to operate on those same principles and recently announced the installation of a one-megawatt solar array carport at its headquarters in Dearborn, Michigan.
The project, which was developed by DTE Energy Co., is the largest solar array in Michigan and the second largest in the Midwest. Not only will it help the utility meet its renewable portfolio targets, it will also aid Ford's own energy efficiency and sustainability initiatives.
Under the arrangement, the utility will own, operate, and maintain the PV system for 20 years on an easement agreed upon by DTE and Ford. After that time, DTE will transfer ownership of the system to Ford—a unique aspect of this project, said Frank Niscoromni, program manager, renewable energy, for DTE Energy.
Using energy from the solar array will contribute to Ford's overall sustainability efforts, which focus heavily on the energy efficiency side, said George Andraos, director of energy and sustainability at Ford Land, a wholly owned subsidiary of Ford Motor Co. Andraos oversees Ford facilities, such as automotive plants and offices.
"Energy efficiency, in our mind, is very important and a critical element in this program," he said. "The best energy is the energy you don't use—that's the greenest energy. At Ford, we look to use renewable sources where we can. We've installed solar, wind, and geothermal where it has made good business sense, and renewable electricity now makes up 18 percent of our electricity consumption."
Under Michigan's renewable energy portfolio legislation passed in 2008, public utilities must obtain the equivalent of 10 percent of retail energy sales from renewable energy sources by 2015. To reach those goals, DTE has amassed about 860 MW of installed wind energy capacity and developed a 22-MW solar program, with 15 MWs of that owned by the company. An additional seven MWs come from smaller systems owned by customers.
The Ford project falls under DTE's SolarCurrents utility-owned program. Under the plan, the utility obtains easement rights to locate commercial-scale solar arrays on suitable property in southeastern Michigan.
DTE also engineers, builds, owns, and maintains the PV systems and receives all of the energy, energy credits, and other environmental benefits generated by the system. The property owner receives an annual income from an easement payment.
The arrangement made good business sense for Ford, Andraos said. Having the PV system provides an opportunity for Ford to closely monitor energy output and how the technology performs.
The partnership between Ford and DTE is nothing new. The two worked together on a 500-kilowatt PV system that DTE developed and built at Ford's Wayne, Michigan, small-car assembly plant in 2011, Niscoromni said. The system was the largest solar project in Michigan at the time it went online.
The success of that PV project got DTE and Ford energy leaders thinking and talking about doing another project, possibly at Ford headquarters.
"Initially the concept was to install the solar array on an empty space, and I wasn't all that excited about it," Andraos said. "When we started developing the project, I suggested, 'Why not make it covered parking?'"
Nova Consultants Inc. of Novi, Michigan, which had worked with DTE on other SolarCurrents projects, conducted a feasibility study to determine whether the site would be acceptable.
"We were looking at what would be the best for Ford," Niscoromni said. "I don't think we were looking at anything that was roof—mount-it was more ground-mount, and we ended up using some of their parking spaces."
Nova also developed a detailed project design that identified exact locations of equipment as well as engineering the carport structural supports.
After evaluating several options and reviewing the feasibility study, Niscoromni said DTE and Ford reached an agreement for the one MW PV carport project.
Altogether, the project covers 68,000 square feet of parking lot, which is three rows comprising 360 parking spaces. Among the spaces are 30 recharging stations for electric cars. Taking away that many employee parking spots during construction posed some challenges.
"There were a lot of preliminary meetings to discuss traffic and how to handle the displaced parking spots during construction," Niscoromni said. "There was a lot of planning and communication through our discussions with Ford about what area was going to be unavailable and where parking would be available. The actual construction site was fenced off, and employees had to park a little bit farther away during construction.
"During the project, we communicated and kept Ford aware of the project timing and that we'd get the parking spaces back as soon as possible."
The idea of solar-covered parking went a long way with getting the employees to buy into the temporary inconvenience that construction would cause. The end result of having covered parking for employees is a nice benefit.
"I didn't hear any complaints," Andraos said. "On the contrary—the employees at the headquarters were excited to be part of the state's largest solar (carport) array."
Permitting was fairly straightforward and involved a building permit and electrical permit from the city of Dearborn, Niscoromni said. DTE also conducted a geotechnical analysis to confirm the depth to install foundations, which involved helical piers.
"There were some interesting findings from the geo-tech," he said. Even at an 8-foot depth, there were not a lot of load-bearing qualities to the soil. In some locations, piers had to go down to a depth of 70 feet to achieve the required torque.
Ford had planned to resurface the parking area but waited until the design was completed. In the meantime, Ferndale Electrical of Ferndale, Michigan, laid the underground wiring that would later be tied into the arrays. Gutters, downspouts, and catch basins were also installed before the top layer of asphalt was applied.
|The one-MW solar power carport project at Ford covers 68,000 square feet of parking lot, which is three rows comprising 360 parking spaces. Among the|
spaces are 30 recharging stations for electric cars.
Whenever possible, DTE likes to use local companies.
"DTE places a high priority on sourcing Michigan-based suppliers whenever possible," Niscoromni said. The single-column V-shaped carport structures themselves were manufactured by Carport Structures Corp. of Oxford, Michigan.
Ford's Andraos praised the carport design, noting it was built with drainage and snow removal in mind.
"It's very well designed to really make it attractive, add efficiency, and provide covered parking," he said.
Crews began installing foundations on the eastern portion of the site and then moved to the western edge so they wouldn't run into each other, according to Judy Pendergrass, DTE project manager. The middle row was last.
Following the foundations, a crew erected the structures in the same order.
Once the structures were up, another crew installed the panels on top. This time they went from east to middle to west to take advantage of being able to work closely together.
"It takes two to three people working together to install the panels because they're working up high in a lift," she said. Altogether, the workers installed 3,700 SolarWorld 280-watt panels.
Niscoromni said SolarWorld is one of two U.S. solar panel suppliers the utility uses for its SolarCurrents program, "and we definitely have experience with SolarWorld on other projects."
Electrical workers then tied together a dozen panels at a time and connected them together to form strings, Pendergrass said.
Rather than one or two central inverters, DTE went with 39 string inverters from SMA America in Rocklin, California, because of the flexibility the newer technology provides. The Ford project also marked the first time that DTE used string inverters.
"I think the main thing we look at in the system—and it's only been commissioned for a couple of months now—is if you do have an issue with an inverter and it goes down, you're not taking the whole array down," Niscoromni said.
The inverters feed the power through underground electrical wiring into an electrical BUS inside the Ford headquarters building for dissemination, thereby reducing Ford's power draw from the grid.
Although the project on paper was to have taken less than six months, record-cold weather temporarily threw a wrench in the plans.
"We had really cold weather here in Michigan," Niscoromni said. "When we got to the modules being installed and working with connections, there's a lot of finger work. There were a number of days when it was a mandatory no-work day just for worker safety. We were kept abreast of the progress and any delays, and opportunities to increase the delivery and get the parking lot back to them. Within the project schedule, there were some days included for inclement weather. But we were able to catch up from the days we lost in February, when the weather turned in March, by having construction crews working some weekends."
As one row of carports was finished, the fencing was moved, and the parking spaces were made available to employees.
The goal was to have the project completed by Earth Day, April 22, "and I think we commissioned the project on April 1," Niscoromni said.