Here comes the sun

By |  October 13, 2014

Solar power is the primary energy source fora California quarry caught between a rock and a hard place over changing electric rates.

PQ1410_soilWhen increased electric rates tripled overnight in 2011, Mark Soiland, Stony Point Rock Quarry president and second-generation owner, knew his family’s California-based company had to find an alternative energy source.

The rate change was due to Pacific Gas & Electric’s (PG&E) move to generate additional revenue. The California Public Utilities Commission eliminated an average rate limiter, which helped business owners keep energy costs at a manageable level.

One impact of that change was removal of the cap on kilowatt-hour rates, which had governed power costs for businesses like Stony Point Rock Quarry. Their monthly electric bill went from an average of $8,500 to as high as $33,000.

“The state of California hadn’t warned us about this change so we were shocked when we saw our monthly bill and realized the impact this would have on our budget,” Soiland says. “Because we were already using a small solar system to power a 3,600-sq.-ft. office building we constructed in 2007, we decided to explore the feasibility of a larger system that would provide significantly more power. We knew we had to do something or our business wouldn’t be economically sustainable.”

Self-sufficient approach

The Stone Point Rock Quarry’s solar system is 202 kW and made up of 33 AllSun dual-axis trackers that follow the sun throughout daylight hours.

The Stone Point Rock Quarry’s solar system is 202 kW and made up of 33 AllSun dual-axis trackers that follow the sun throughout daylight hours.

Stony Point Rock Quarry supplies products for construction and landscape companies, serving wholesale and retail customers for major construction projects and individual home landscaping needs. Their products, which include specialty items and custom mixes, are used for jobs of all sizes such as underground pipeline work, site work, road and driveway construction, septic system installation, building construction, concrete work, and landscaping improvements.

“The solar system that powers our office building is a residential-sized, system,” Soiland says. “The new system, sized to provide power for our crushing and classifying plant, is much larger. The plant has a 1600-amp main service panel. What we wanted to achieve with the solar power was an essentially net-zero metering system that allowed us to produce 100 percent of our power needs.”

The Soilands looked to North Coast Solar, a solar general contractor in Santa Rosa, Calif., to provide the information they needed to develop a new energy plan. Brian Hines, North Coast Solar owner, worked with the Soilands to organize the project’s design, engineering, installation, utility interconnection and utility rebate processing.

“Before we installed the new solar system, Stony Point Rock Quarry had one electric meter for their plant,” Hines says. “As part of this project, we installed two electric services, which qualified the quarry for a different rate schedule – one that didn’t include demand charges; just a bundled [kilowatt-hour] charge. The result is a much more solar friendly rate schedule.”

In analyzing Stony Point Rock Quarry’s electric rate history, Hines found that nearly 50 percent of its power costs were due to demand charges. Demand charges are based on the highest rate of energy use at any time during a billing period.

Owners Marv Soiland and his son Mark pose in front of the company’s very first tractor.

Owners Marv Soiland and his son Mark pose in front of the company’s very first tractor.

“The large 200- and 400-hp motors in rock crushers can really peg a demand meter,” Hines says. “Solar power allows the quarry to obtain the energy they need during peak demand hours without pushing rates to an unprofitable high.”

The quarry’s solar system is 202 kW and made up of 33 AllSun dual-axis trackers that follow the sun throughout daylight hours. Each tracker has 24 ReneSola 255-watt modules and one SMA 6-kW inverter. Performance with the dual-axis tracker is 40 percent higher than with a fixed array.

Overall, the system will generate more than 400,000 kilowatt-hours per year.

“Each tracker has a GPS unit that locates the satellite and locks the tracker into position,” Hines says. “They also have a wind sensor that will place the trackers in a prone position if wind speeds exceed 30 mph. With two monitoring systems, the solar power unit can be viewed on the Internet.”

Cost and savings

The company’s products are used for jobs of all sizes, such as road and driveway construction, concrete work and more.

The company’s products are used for jobs of all sizes, such as road and driveway construction, concrete work and more.

The project team for Stony Point Rock Quarry’s solar system includes installer North Coast Solar, Lunardi Electric, Harris Co. Concrete Construction, Dave Soiland Co., Northgate Ready Mix, RGH Geotechnical Consultants and ZFA Structural Engineers.

Solar module costs have decreased dramatically over the last 10 years. Hines says a solar module that would have cost $1,000 in 2004 now sells for $250. Advances in inverters, which convert direct current electricity to alternating current electricity, also make the systems more affordable and efficient.

“Dual-axis trackers may be initially more expensive to install, perhaps 20 percent more,” Hines says. “However, the 40-percent-added performance makes it worth the cost, especially over a 25-year lifecycle.”

Stony Point Rock Quarry’s solar modules have a manufacturer’s 25-year warranty. The rest of the system has a 10-year warranty.

“The quarry will receive approximately $50,000 paid over five years from the California Solar Initiative rebate,” Hines says. “The rebate is based on the system’s [kilowatt-hours] production. The project was also eligible for a 30-percent federal solar tax credit and accelerated five-year depreciation.”

Soiland expects a seven- to eight-year return on investment on the solar system because of the savings the company is experiencing in power costs.

The Stony Point Rock Quarry will receive about $50,000 over five years from the California Solar Initiative rebate.

The Stony Point Rock Quarry will receive about $50,000 over five years from the California Solar Initiative rebate.

“The solar system allows us to essentially avoid most electricity penalties we used to incur in each billing cycle,” Soiland says. “In addition to the cost savings, we are realizing an environmental stewardship payback, too. What hope other businesses and individuals gain from our experience with energy issues is that there are sustainable energy solutions available. Solar power isn’t the only option. Wind and hydro systems are also available.”

Path to solar

Wind power wasn’t an option for Stony Point. Wind studies in its area demonstrated that most significant wind events occur there during nighttime hours. Wind turbines there would also cause environmental concerns in regard to bird populations.

“Physical maintenance for the solar panels is pretty minimal,” Soiland says. “We’re in a rural environment with pasture areas surrounding the quarry. Dust and pollen in a dry cycle could mean we’ll have to clean panels more frequently. The mechanical element of the system requires routine maintenance. On cloudy days, we don’t generate as much power and if winds are high the solar system essentially goes to sleep. In the seven months we’ve had the system, clouds and winds haven’t been an issue even one time.”

In order to bank solar power, Soiland plans to install a stationary battery pack that will be online late this year. Over time, Stony Point Rock Quarry would like to triple or quadruple the size of the solar fields on available land. The expansion would allow the company to provide power for Sonoma Clean Power, the local power agency.

An excavator loads rock at the Stony Point Rock Quarry. The company supplies products for construction and landscape companies, serving wholesale and retail customers for major construction projects and individual home landscaping needs.

An excavator loads rock at the Stony Point Rock Quarry. The company supplies products for construction and landscape companies, serving wholesale and retail customers for major construction projects and individual home landscaping needs.

“We have the real estate available and our company philosophy is that we do our best to take care of people in the community where we do business,” Soiland says. “That perspective applies to providing needed aggregates, designing waste solutions, recycling water and finding a way to deliver economic solar power. Our expansion plans are dependent on California’s PUC (Public Utilities Commission) policies.”

The quarry has been the center of much attention for its innovative power solution. From the feedback they’re receiving, the Soilands believe the general public sees the development as a very positive development.

“Travelers on the public thoroughfare can see the system from the highway,” Soiland says. “No one in this area has seen anything like it before. As far as we know, it’s the only system like it that’s been installed on the West Coast.

“The decision to go solar not only made economic sense but really aligned with [our] environmental values,” Soiland adds. “We have always strived to be as sustainable and environmentally responsible as possible.”

Take note

A solar module that would have cost $1,000 about 10 years ago now sells for $250 according to Stony Point’s Mark Soiland.


Loretta Sorensen is a freelance writer in Yankton, S.D. She produces material on a variety of topics, serves as a ghostwriter, and has authored her own books.

Photos: Stony Point Rock Quarry

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