Net zero energy electrifies sign-maker

Solar roof produces as much electricity as manufacturer consumes

By Kate Bachman

January 27, 2012

Philadelphia Sign Co. marked its centurial anniversary in 2011. Some companies celebrate their anniversaries with a party. Philadelphia Sign commemorated it by going net zero energy.

Philadelphia Sign Co. has manufactured some notable illuminated signs for prominent customers in the course of its 100-year history—from elaborate, sparkling cinema marquees to luminous storefront signage to elevated, eye-catching channel letter signs for banks and automotive dealerships. Its client list has included recognizable companies as diverse as Subaru, Gimbels, Chase Bank, Target, and Buffalo Wild Wings.

The manufacturer just marked its centurial anniversary in 2011. Some companies celebrate their anniversaries with a party. Philadelphia Sign commemorated it by going net zero energy.

That's right, zero.

Philadelphia Sign installed a 910-kW rooftop solar energy panel array system on one of its two production plants that generates more electricity than the facility—including its operations—consumes (see Figure 1).

Bob Mehmet, president and CEO, isn't sure when he's going to get another power bill. "We haven't gotten an electric bill since July 2011. We produce well over what we use."

The astute businessman didn't set out to pursue net zero energy, and don't go mistaking him for a granola-munching tree hugger.

"We wanted to get as much solar power as we could. It just happened to work out that way," Mehmet said.

"We just heard about net zero three months ago, and we realized, 'Well, that's what we are,'" said David Sheffield, environmental services manager and project lead engineer.

Mehmet added, "First and foremost, just so everybody knows, we did this because it made good business sense. Second to that is that we do want to manufacture as green as possible–or completely green. Our customers are demanding it and wanting it more and more. That is the wave of the future."

Building a Business Case for Net Zero

Model. Near the plant is a brownfield site that PPL Renewable Energy, in partnership with the Pennsauken Sanitary Landfill and Aluminum Shapes LLC, converted to a renewable-energy park. The park comprises a 2.6-MW photovoltaic (solar) ground mount system and a 2.8-MW methane gas-to-energy plant.

The park's solar array provided a model for the manufacturer, both in terms of estimating power generation capacity and longevity.

"As we began to make our business case for doing this, the proximity to the Pennsauken Sanitary Landfill made it pretty easy for us to investigate. We knew that it [solar] was a technology that would withstand New Jersey weather," Sheffield said, which was one concern because the plant's location on the bank of the Delaware River makes it vulnerable to extreme weather, including lightning strikes.

Mehmet and Sheffield evaluated the financial benefits and costs of net metering, first by calculating how much power the facility was consuming. The plant's electricity needs include lighting, HVAC, and machinery. Although the production equipment is not power-intensive, the plant is in operation for two and three shifts, six days a week. Then they researched how much power the solar array could generate and how much revenue could be realized by selling solar renewable energy credits (SRECs). Finally, they researched available tax credits and other incentives.

Net Metering. The company is able to capitalize on an arrangement with the utility called net metering. As of November 2010, net metering was offered in 43 states, including New Jersey.

"The meter can either go forward or backward," Sheffield explained. "There might be a part of the day when the meter is going forward because we're using power from the grid. But then during the hours of peak generation, it goes backwards." So at the end of the day, if the amount of energy consumed equals zero or the negative side of zero, that's net zero energy, he said.

The U.S. Department of Energy, Energy Efficiency and Renewable Energy defines net metering this way: "Net metering enables customers to use their own generation from on-site renewable-energy systems to offset their consumption over a billing period by allowing their electric meters to turn backwards when they generate electricity in excess of their demand. Customers receive retail prices for the excess electricity they generate."

SREC. SRECs are part of the state of New Jersey's very progressive renewable-energy plan that requires utilities to source 22.5 percent of their electricity from renewable energy by 2021. In fact, according to the New Jersey Board of Public Utilities, the state is one of the fastest-growing markets for solar photovoltaic in the U.S., second only to California in terms of installations and installed capacity (see It's Always Sunny in New Jersey sidebar).

"New Jersey has an amazingly high goal for power companies to have to either produce renewable energy or buy renewable-energy credits. If they don't meet the goal, they are assessed a penalty of about $685 per 1,000 kWh. So that's what created value in the SREC market," Sheffield said. "They're traded through brokers, just like any other commodity."

Sheffield said that the SRECs are more valuable than the savings in electricity, although the price varies, based on many conditions. "The last three years they have averaged over $670 apiece. So 1,000 kWh at 15 cents per kWh is $150, so you're saving $150 of electricity. But you could sell the SRECs in 2011 for as much as $670."

Further enhancing the installation of solar energy are state laws prohibiting restrictions on it. "The state of New Jersey passed laws that state that the local municipalities can't tax it, they can't increase your tax liability, they can't increase your property value … they can't stop you even if they don't like the way it looks," Sheffield relayed.

The state had increased its installed solar capacity from 205 MW in November 2010 to 531.7 MW a year later.

Fortuitously, the company was in a financial position to purchase the solar energy system without taking out loans.

"So, once we fully understood all the financials, it became a no-brainer," Mehmet said.

How the Solar PV System Works

The Pennsauken production building was built in the 1930s as a steel mill. A large, one-story building complex with flat roofs is ideal for a large solar array, Mehmet and Sheffield discovered. The 225,000-sq.-ft. flat roofs accommodate roughly 5 acres of solar panels.

The hundreds of PV arrays are equipped to power the 910-kW rooftop system, generating 1.1 million kilowatt-hours (kWh) of electricity per year—enough to satisfy the electricity needs of the entire signage-producing plant (see Figure 2).

Philadelphia Sign acted as its own general contractor, which Mehmet estimated saved about $1.5 million. "When we started this project, we thought, 'How hard can it be? ... some solar panels, wiring, inverters...'

"But when we started getting quotes from solar companies, the quotes we were getting were $1 million, $1.5 million more than it ended up costing. That's why we decided to take the management on ourselves," Mehmet said.

The company hired solar installers and integrators, but purchased the panels, wires, and conduit directly, eliminating the middle man, Mehmet said. "We even bought the blocks [to weigh down the panels] from EP Henry, and we bought so many they had tractor-trailers come in for blocks. People thought we were doing some type of landscaping for a park in the center city."

Solar Panels. The company purchased 4,790 MAGE SOLAR POWERTEC® PLUS 190/5 PV modules.

One critical selection criteria was that MAGE SOLAR's modules have a 30-year power output guarantee. "They will replace the panels if they can't produce 80 percent of their nominal power after 30 years," Sheffield said.

Reliability was another criterion. "We didn't go with the cheapest panels. We went with MAGE SOLAR because they were reputable. You don't know what you're getting out of China. For a little bit of savings, we didn't want to take that chance. It's too big of an investment," Mehmet said.

The panels produce some power even with 10 inches of snow on them, Mehmet said. "We've seen 3 feet of snow up here. The wind blows the snow off and it's gone by lunch," he said.

The solar modules are available in various sizes and wattages, from small with high output per square foot to panel wattages from 190 to 250. "We had to size the system of panels to fit the different roof sizes, obstacles, orientation, and panel availability," Sheffield said.

Part of the "fit factor" is that each module must be spaced so that the shadow it casts does not encroach upon another module, Sheffield said (see Figure 3). "The taller the panel is, the higher the tilt and the bigger the space you have to allow between the panels. These are spaced so that when the sun comes up just over the horizon, the shadow never encroaches on the next panel." Shadows reduce the efficiency of a whole string of panels, he said.

Another size consideration was weight. Engineering calculations determined that the rooftop array could not exceed 7 lbs. per sq. ft.

Mounting, Installations. The solar modules are mounted on 10,000 stainless steel angle racks on the facility's roof. The mounting method is a nonpenetrating, ballasted system. "We didn't want to penetrate the roof. That's just creating problems," Sheffield said.

Because the manufacturer is equipped for metal fabrication, Mehmet considered making the racking system in-house to save money, but decided against it. "The more I thought about it ... two brackets per panel, 10,000 brackets … If these things started to blow off, at this scale, if I'm going to save myself $50,000, is it really worth it? Not when you're putting out $4.5 million," he said.

Philadelphia Sign hired and managed a team of solar experts to work with the company to install the solar rooftop system.

White Roof. The roof underwent substantial upgrading before the installation, including a GAF insulated and reflective EverGuard® Extreme™ thermoplastic polyolefin (TPO) roofing system. The "white roof" is designed with advanced heat and UV protection. TPO was engineered with solar installations in mind, according to the company.

Rooftop PV array systems typically are mounted directly to a low slope roofing membrane. Temperatures are as high as 190 degrees F near the solar panels mounted directly to white roofing membrane, the GAF Web site reports.

Inverters, Transformers. The solar panels generate direct current (DC). That power is transmitted through conduits on the roof into a transformer that brings the voltage down to about 480, which is the voltage that the plant uses (see Figure 4). Then the solar inverters, purchased from SMA America LLC, change the electricity from DC to alternating current (AC).

Then the electricity goes through conduit over the roof and into the building for use. Alternatively, the electricity is fed into the grid at the plant location where electricity would otherwise be sourced from the grid.

"To feed the grid, we have a very antiquated system, an old Delta 3 transformer system that's at least 40 years old," Sheffield said. "To integrate a four-wire, state-of-the-art solar system into the old grid system took a little bit of thought and a lot of engineering. There were a lot of challenges. We did put in a very expensive interface."

The utility company limits how much electricity it will accept from Philadelphia Sign's rooftop system through net metering. "They limited us to 650,000 W, and at the right time of year, we produce a maximum of 910,000. We generate a lot over a year," Sheffield said.

"We put so much solar up here that the power company was concerned," Mehmet said. "Since whatever power we're not using goes back into the grid, one of their big concerns was that they would have to accept a lot of excess power, like on the Fourth of July when we're closed for four days. The utility didn't know if the existing grid wiring could handle that type of wattage going back into the system," he said.

"When they built the grid 40 years ago, they weren't thinking about people producing power on-site and then feeding that back into the grid," Sheffield added.

Net Results of Net Zero

Mehmet emphasized that his decision to pursue the green endeavor was based on sound economics. "We just spent $4.5 million on this new endeavor. We're a for-profit business, so net zero has to make business sense. And that's what we made our decision on. Does it make good business sense?"

21⁄2-year ROI Clinches the Deal. With an ROI of 2.6 years and the 30-year lifetime power guarantee on the modules, the system is certain to save the sign-maker millions of dollars over its lifetime.

"If the ROI were 10 years, I would have thought long and hard about it. With the incentives that are out there, it definitely paid off. That's why the incentives and grants are there, and the accelerated depreciation that the government offers," Mehmet said.

"When we did the original ROI and it came in at 2.6 years, I spent a lot of time making sure that the figures were correct. And then I said to David, 'Tell me where I sign!'"

Not only has the company saved substantially on its electric bill, it has made money on the SRECs. "We sold our first month of SRECs for $670 per 1,000 kWh," Sheffield said.

Positive Customer Reaction. "Green manufacturing is an important thing to our customers. When they hear that we're producing net zero energy, they like it because they can take credit for it in their sustainability percentages. That's especially important for our bank customers—almost all the banks are going in that direction," Sheffield said.

"Somebody like TD Bank, a Canadian bank with U.S. headquarters right here in Cherry Hill, can now tout the fact that their signs are being manufactured with renewable energy; therefore, they are getting something manufactured without a carbon footprint," Mehmet added.

Good Fit With Green Product Line. The sign-maker's green efforts reflect its foray into green lighting products. "We have integrated all kinds of green illumination products into our signs because the market has gone that way," Mehmet said.

Philadelphia Sign is capitalizing on the trend for illuminated signage to be equipped with LEDs rather than neon and fluorescent lighting (see Figure 5). "If you came here 15 years ago, everything would be illuminated with T12 HO fluorescent tubes and neon," Mehmet said. "You won't see any neon now. Neon is gone. It went from being 'the man' for 40 years to being a little wrinkle. LED technology just killed it."

The manufacturer is finding great success with its green approach, not only in constructing new LED-lit signage, but also in retrofitting illuminated signage by replacing neon and fluorescent lighting with LEDs.

Mehmet said he saw the turn in technology about five years ago. "That's when the high-intensity, 40- and 50-lumen white LEDs came out, and that revolutionized the industry. And now we have 100-lumen LEDs. There's no question that it's a better lighting source," he said.

The downward cost trend has made LEDs an easy choice. "When LEDs were $40 a linear foot and neon was $5 a linear foot, it was not an easy call. But now that they're nearly the same price, it is," Sheffield said.

Purchase price is not the only factor. LEDs are much easier to work with because they don't require the complexity of crafting curving glass and the technical difficulties involved in injecting different gases, Sheffield said. "Blowing the glass with all the curves, twists, turns … that takes a person with a lot of experience and artistic skill. Then all the oxygen has to be vacuumed out of that to fill it with gas and sometimes mercury. And then you have to seal the electrical ends. It is a very artistic endeavor."

Finally, LED lighting's exceptional longevity eliminates the cost and difficulty of changing out expired lights.

"That's one of the reasons Regions Bank is doing retrofits nationally," Sheffield added. "I've got guys working at 208 feet in Miami today because they had neon out in three of their letters."

Excess Power Benefits Local Food Bank

Because the power company limits the electricity it will accept to 650,000 W, the sign-maker had to decide what to do with its overage. One alternative was to shut off one of the inverters. "We were determined that that would never happen," Sheffield said.

Another alternative was to try to use the excess electricity by leaving additional lights on in the plant on the weekends. "You'd just be using sunlight to burn bulbs unnecessarily," he said.

Mehmet found a third, optimal alternative. "We knew that we needed to use some excess power, and we didn't want to just waste it. The Food Bank of South Jersey supplies food for 250 distribution facilities. We offered to let them set them up here and use our electricity. That would increase our basic load and it would help them too.

"What we found out was that they had a bigger need for dry goods storage," Mehmet continued. "We have an extra warehouse here that we weren't using. We had space, and our electricity for lighting was basically free, so we're storing food for the food bank at no cost."

The spirit of generosity spread companywide. Employees at the two main production facilities are competing for which can donate the most to the food bank.

Mehmet shies away from sounding like a good guy for helping the food bank—even though he is.

"We had a need; we had more power than we used on the weekends. Then we saw that they [the food bank] had a need and said, 'Maybe this will help both of us.'

"That was not the whole point of the matter, but when you're going down a road of doing something like this, it's amazing what you're able to do to help other people, and it helps your company too."

Photography by Carver Mostardi for Green Manufacturer.

More information about available incentives can be found at U.S. DOE, EERE, Database of Incentives for Renewables & Efficiency.

Philadelphia Sign Co., 707 W. Spring Garden St., Palmyra, NJ 08065, 800-355-1460

MAGE SOLAR USA, 720 Industrial Blvd., Dublin, GA 31021, 877-311-6243

SMA America LLC, 6020 W. Oaks Blvd, Ste. 300, Rocklin, CA 95765, 916-625-0870