Those who have doubts about the merits of solar energy systems might talk with Dick Melsheimer, CEO of Melfred Borzall’s Directional Drilling and Horizontal Earth-Boring Tools. His company uses solar energy to manufacture horizontal directional drilling tools for contractors at plants in Santa Maria and Santa Fe Springs, Calif.
The electrical loads imposed by the plant’s welders, lathes and other production equipment represented a sizable operating expense before Melfred Borzall implemented conservation initiatives a few years ago to improve energy efficiency. After attending an informational workshop hosted by his electric utility, PG&E, Melsheimer was convinced that his operations demanded more energy efficiency, and that solar could be a big contribution.
His electrical bill dropped during the next five years from $36,000 in 2003 to about $4,000 following his investment in a photovoltaic solar energy system. That reduction occurred even as 150 hp of new equipment was added to the Santa Maria plant’s electrical load. The system will pay for itself in seven years, long before the warranty on the solar panels expires.
Melsheimer acted in the wake of California’s wave of rolling blackouts earlier this decade. Skyrocketing electricity charges and unstable conditions in the Middle East threatened not only his family-owned business but the wellheads of the western industrial world’s oil supply. He felt the time had come to explore ways to make his company’s operations more energy-independent.
“As an independent, family-run business, we had the opportunity to choose to operate in a more environmentally responsible manner,” he says. “You can’t do everything that’s needed to combat global warming, but we can do something. What we’ve done here is our little part, perhaps, of the overall solution.”
The Santa Maria plant has added an array of photovoltaic panels that provides more than 80% of the electrical power for the plant’s operations. A planned expansion should make the plant independent of the PG&E supply.
Plant processes require a substantial supply of 480 V electricity for lathes, welders and other equipment. In addition, there’s office lighting and air-conditioning to run.
The electrical design for the plant’s solar energy exchange is simple. The direct current the panels produce passes through an inverter that outputs usable AC power. There’s no on-site battery storage.
The electric utility has a seasonal rate structure with higher summer charges of 18 cents/kWh versus the 13 cents/kWh during the rest of the year. The utility’s net-metering program delivers a corresponding credit toward the billing if an alternative energy system linked to the PG&E grid produces more electricity than it consumes. That means when Melsheimer’s plant closes on weekends or other daylight hours, the meter runs backward and the surplus energy the solar panels generate results in a credit.
Solar panels on the roof of the plant reduced electricity bills from $36,000 in 2003 to $4,000 in 2007.
The arrangement benefits the utility by offsetting the need for a corresponding amount of generation during peak demand periods. Conversely, the plant can draw from the grid when solar production falls short of plant requirements. The technology is reliable, Melsheimer emphasizes, and underscores why solar is no longer an exotic alternative, but a proven supplemental energy source.
The solar system was installed in two phases — 648 125-Watt panels in 2004 and 357 165-Watt panels in late 2006. The 500,000 kWh of electricity generated in 2007 equals the yearly power need for 30 homes. Equally important, this plant avoided 620,000 lbs. of greenhouse gases that fossil fuels would have produced as a byproduct during electrical generation.
REC Solar Inc. designed and installed the system. The solar contractor engineered the first group of panels to mount on elevated clips directly atop the south side of the double-slope metal roof. The 4° angle to the horizontal is ideal for summer collection and the use of non-penetrating clips to mount the panels avoided drilling holes through the membrane of the standing-seam metal roof system. The panels weigh only 2.7 lbs./sq. ft., so their additional load required only modest structural reinforcement of the building.
The solar system covers 80% of the facility’s total power requirement, which includes lathes and welders, along with lighting and offices.
The additional panels added in 2006 to the opposite slope of the roof are elevated at a 20° angle to the horizontal on bracket framing for optimum collection from that side. REC’s approach to mounting the panels not only preserved the seamed metal roof membrane , it would be compatible on millions of other square feet of similar metal roofing on similar buildings.
The $600,000 investment in the first system was reduced 50% by rebates, and earned 30% tax credit from the federal government and another 15% from the state, bringing the company’s net outlay down to $88,000. That should be recovered in five years. The silicon-based solar panels are guaranteed for 25 years, Melsheimer says. In his opinion, the advantages are evident.
The solar system will save at least $1 million during the warranty period and should continue to produce at least 80% of their rated capacity thereafter, a spokesman for the solar contractor says.
The system remains one of the largest between California’s Ventura and Santa Barbara counties. “Solar electricity is great for business and good for the environment,” Melsheimer concludes. “To me, it’s a no-brainer.”