Structural planning and installation decisions for dual-use PV projects, of course, start with preserving the most important asset — the land. At a base level this means sourcing trackers that require zero grading to preserve the topsoil and natural quality of the land.
EPCs should consider current and future crop selections, soil cultivation and planting methods, and harvest requirements for the fields being planned for agrivoltaics projects as well, says Jeff Sharpe, CEO of Stracker Solar, a dual-axis solar tracker company.
“Hay, mints, and legume crops are often cut, rowed, and bailed in concentric loops moving in from the fence lines,” Sharpe says. “Row crops such as vegetables, tubers, and flowers are often planted and harvested in straight rows on the largest square dimension of the field. Because crops and harvest styles can be changed every few years, it is wise to plan solar structure layouts and system designs to work well with either basic layout and harvest style.”
Straight lines of large, robust structural poles, typically spaced 50 ft to 80 ft on center, allow for the efficient operation of the larger planting, harvest, and combine tractor systems. Minimum 14 ft clearances of the primary horizontal solar support systems allow unhindered operations of most farming equipment, though higher clearances might be required for the larger combine systems.
“As typical moldboard plow systems work in the top 6 to 8 in. of soils, electrical conduits and wiring systems are typically safe at a minimum 18 in. below the soil surface, though potential future soil elevation changes or other unique circumstances might warrant running deeper. Keeping all wiring systems contained in buried conduits or vertical pole elements is advised to avoid accidental wire catch by active farm equipment,” Sharpe says.
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eBOS not eat-BOS
The implementation of an effective and organized cable management system (CMS) is important for all solar projects, but CMS is especially crucial for agrivoltaics projects. Avoiding ground disturbance is key here too:
“Aboveground cable management should be a key consideration for EPCs,” says Jonny North, product manager at Gripple. “By eliminating the need for trenching, which can disturb soils and damage crop roots, managing cables above ground is an ideal solution for agrivoltaic, especially those on fruit-growing or vineyard sites where the risk of damaging established roots needs to be minimized.”
However, exposed wires and cables are more at risk if grazing animals are part of the agrivoltaics site plan.
“EPCs should consider the effects grazing animals may have on above-ground cable management systems. If electrical cables are not properly secured, then owners will incur additional labor costs after installation to re-install cables that are impacted and dislodged by grazing animals. Reducing avoidable O&M costs should be a priority for EPCs,” says Tim Wedding, director of solar development at CAB Solar.
Sites with agrivoltaic elements incur more frequent site maintenance in general than solar projects without agrivoltaics because both crops and livestock require more care.
“For instance, co-locating solar panels with grazing animals, like sheep or goats, opens up the risk of the animals interfering with or chewing on the cables, which would have catastrophic impacts on the operation of the solar power plant and the well being of the grazing flock,” says Scott Rand, CEO of AWM. “Having the flexibility to increase the height of or easily re-route the CMS could be the deciding factor between a successful or a challenging project.”
That extends to the tracker system too.
“Customers should ensure that their chosen tracker product is adequately designed for agrivoltaics purposes,” says Jenya Meydbray, CCO with Nevados. “For example, with controls, most tracker companies tout remote operations of their trackers, but for an agrivoltaics project expecting increased on-site presence and operability, the ability to control trackers with physical buttons becomes valuable. Safety is also another key consideration with moving parts and people involved to ensure that tracker algorithms are adjusted for human and animal presence.”
Tags: Affordable Wire Management, agrivoltaics, CAB Solar, Gripple, Stracker Solar
