Spotsylvania Solar

617 MW solar facility in Spotsylvania, VA

Project Details

Market

Energy

Location

Spotsylvania, Virginia

Project Partners

Mortenson (EPC)

Construction Timeline

Completed in 2023

Project Size

617 MW | 6,350 acres

Our Scope

Erosion control supplier

Spotsylvania Solar Farm in Spotsylvania, VA

About the Project

The Spotsylvania Solar Energy Center is the largest solar project east of the Rockies.* The 617 MW solar farm encompasses approximately 6,350 acres of land including 3,500 developed acres and 2,000 acres of preserved land.
Spotsylvania Solar is comprised of four separate solar projects: Pleinmont 1, Pleinmont 2, Richmond Solar and Highlander Solar. Despite its size, Spotsylvania Solar is almost invisible to the naked eye because it is surrounded by forest cover. The solar facility has all single axis tracking solar panels that follow the sun for maximum solar output. The solar power generated by Spotsylvania Solar is estimated to power 111,000 homes at peak output and offset 340,000 tons of carbon dioxide emissions each year.

Microsoft purchased 315 MW of solar energy from Pleinmont 1 and Pleinmont 2. The energy output from these two Virginia solar farms enables Microsoft to make a significant step towards its clean energy goals. At the time of purchase, this represented the single largest corporate purchase of solar energy.
Before the site was developed into the Spotsylvania Solar Energy Center, the land was used for logging and timbering. The Virginia State Corporation Commission approved the massive solar project in 2018 and construction began in 2019. All four solar projects are active and construction is estimated to finish by mid-2023.

High Volume Site Work Supplier

Our team at Colonial Construction Materials supplied Mortenson (EPC) and many sub-contractors with erosion control and geosynthetic solutions throughout the construction of Spotsylvania Solar. Through material supply and design assistance, Colonial Construction Materials, led by Pat Branin, supported the careful development of thousands of acres of land in northern Virginia.

1,100,000

pounds of hydromulch

152,000

pounds of custom grass seed

80,000

pounds of fertilizer

79,000

pounds of lime

33,000

rolled erosion control products

104,000

linear feet of compost filter sock

22,000

square yards of geogrid

41,000

square yards of geotextile fabric

“Working in Virginia, we knew managing our erosion control and vegetation was critical to the success of the Spotsylvania Solar project. At over 3,000 acres of cleared land, we needed someone who would be able to keep up with the demand of BMPs we would need to stop erosion and achieve vegetation growth. Colonial Construction Materials was integral to the project as they provided large BMP deliveries multiple times per week. They were able to source difficult to find geotextiles and seed mixes, maintain solid inventory and provide us extensive customer support even through the pandemic. I would recommend working with CCM for any project big or small if you want a dependable and knowledgeable source of materials for your project.”

Emily Raymond
Assistant Superintendent
Mortenson

Project Challenges

Retention Pond Construction

Spotsylvania Solar was developed on approximately 3,500 acres of land. In order to meet Virginia stormwater regulations, the site required of hundreds of retention ponds that would collect and retain stormwater runoff.
An extensive network of ditches conveyed runoff to the 388 stormwater ponds. As the ditches and ponds were graded and constructed, Mortenson proactively installed erosion control blankets to any slopes greater than 3:1. Installing erosion blankets during pond and ditch construction is not standard practice on most sites. However, because of the size of Spotsylvania Solar Farm and the scale of land development, Mortenson took proactive action to protect slopes during and after pond construction in order to mitigate soil erosion.
An assortment of erosion blankets were installed but many slopes were lined with Straw Coconut blanket. This double-net blanket offers superior erosion protection than Single Net Straw Blanket because of the coconut fibers and two nets.
One pond located at the back of the site presented particularly difficult challenges for erosion control. A gradual slope covering approximately 23 acres leads towards the back of the project. At the bottom of the site, the gradual incline steepens to a 2:1 slope that terminates at the stormwater pond.
Runoff flows down the gradual incline and then gains velocity when it reaches the 2:1 slope. This slope was regularly subjected to high concentrated flow that was further exacerbated by a neighboring access road.
The concentrated flow was severely eroding the slope, creating rills and threatening the stability of the structure. Multiple erosion control products including Turf Reinforcement Mats and articulated concrete block mats failed because they could not support the volume and velocity of water.

Recyclex Turf Reinforcement Mat for BMP embankments

Solution

GEOWEB® Geocell Slope Protection System

After the previous products failed, Pat made a visit to the site to inspect the slope. The critical reason the products were failing was because fast-flowing water was getting under the material.
The solution Pat suggested was the GEOWEB® Slope Protection System. GEOWEB® geocell created structural support on the slope that was not achievable with erosion control blankets or turf reinforcement mats.
The cellular confinement system has perforated cells which allows water to infiltrate vertically and flow horizontally while holding soil in place and preventing soil loss.
2,760 square feet of GEOWEB GW30V6 (mid-size cell, 6-inch depth) was installed over the 2:1 slope using TP-225 tendons and ATRA® Tendon Clips. The tendons were tied to a buried deadman pipe and secured to the geocell system with ATRA® Tendon Clips that provide twice the pull-through strength of alternative load transfer devices.
The GEOWEB® system was filled with on-site fill which is a significant cost-saving factor for solar sites and an advantage for projects that do not allow imported fill.
After installation, the slope was hydroseeded and covered with a Straw Coconut Erosion Control Blanket for additional protection.

Watch the Case Study Video

“Pat and his team at Colonial Construction Materials were a tremendous supplier for our solar project in Spotsylvania over the last 3 years. They supported our site with BMPs, seeding mixes, geotextiles, drain tile, product samples, and even product demonstrations to help us further prevent and mitigate erosional issues on our 3500 acre solar site with 388 sediment basins. This site called for numerous, highly specific BMP’s to be installed and construction always moved at a very rapid pace. Colonial continued to supply us with all necessary materials and keep up with our busy schedule without issue. The site also had very specific restrictions, including extremely strict delivery times. Colonial Construction Materials helped us adhere to these restrictions and continually delivered multiple truckloads of materials a day to support both Mortenson, as well as our civil and seeding subcontractors. Once again, we cannot thank CCM enough for their dedication to serve and supply our project over the last several years and look forward to the chance to work with them again in the future.”

John Garceau
Assistant Superintendent, Solar and Renewables
Mortenson