2  Design Pressures

Every solar design is pushed from several directions at once. The price a developer bid pushes toward a simple rectangle of panels. A tractor that has to fit underneath pushes the panels up and the rows apart. A neighbor’s view pushes for a screen along the road, a buyer’s scorecard pushes for the credits it counts, and a county ordinance pushes for its setbacks. This lexicon calls these forces the design pressures: nine of them, each pushing the design in its own direction, and each with someone arguing for it in good faith.

Figure 2.1: Nine pressures bearing on one site at once, arranged by the direction each usually pushes. The two colored groups never meet, because the three whose direction is decided by the site, the buyer, or the county sit in the gray wedges between them.

2.1 The nine pressures

In the usual case, a ground-mounted project bid into a US market today, three pressures push toward restoration, three push against it, and which way the remaining three push depends on the site, the buyer, or the county. The usual case is not every case. Table 2.1, at the end of the chapter, gives what each pressure asks for and where it often changes sides. Restorative goals is the pressure this lexicon exists to advance, but it is still one force among nine, and it loses to the other eight more often than not.

2.2 Where the pressures collide

Whatever a design leaves unresolved is its design tension. No combination of lever settings brings it to zero, because the nine cannot all be satisfied and the project still has to get built. What varies is how much tension is left, and who carries it. The hardest collision is between two pressures that both push toward restoration. Established habitat and rebuilt soil take years to create, and they do not come out cleanly when the array does, so a project designed to leave no trace and a project designed to heal the ground are not always the same project. The combinations that leave the least tension get built again and again, and those are the archetypes of Chapter 7.

2.3 How the pressures vary by region

The same nine pressures act on every site, but they carry different weight in every region. Shade that relieves a water-stressed crop in Arizona can cut corn yields in Ohio. Pooling 367 shade-versus-sun yield comparisons, one review found agrivoltaic shade turning from loss to gain near 30 °C air temperature (Merheb et al. 2025). Retiring irrigated ground above a depleted aquifer has no equivalent in a county whose crops run on rain. Six factors shift the weights: sun and cloud, the grid operator, aridity, latitude, the cropping system, and irrigation. The words travel between regions and the weights do not, which is why this lexicon argues for an aim and leaves the dimensions to the site. The chapters that follow show the factors at work: the grid operator in which zones exist, latitude in how much ground a megawatt takes, irrigation in what counts as impaired ground, and aridity and the crop in what shade does for a farm.

TipAt Rabbit Hills

Energy yield set the array’s shape: low panels in close rows, the layout a developer builds anywhere. Agricultural production is the pressure that kept the sheep on the pasture, and the low clearance settled which animals it could be: sheep, not cattle. The measurements in Chapter 6 suggest that neither pressure had to give up much. The flock gets shade and forage under the panels, and the ground beneath the array is grazed rather than mown.

2.4 The nine pressures in detail

Table 2.1: The nine pressures and the direction each one usually pushes, for a ground-mounted project in a US market today. The third column is a direction, not a verdict on anyone advocating it.

Pressure	What it asks for	Which way it usually pushes
Restorative goals	Wider rows, mixed ground cover, and a plan covering all thirty years	Toward. The one this lexicon argues for
Community acceptance and benefit	A say early enough to change the design, and something paid back: tax revenue, subscriptions, local hiring, part-ownership	Toward, mostly. Payments offered without a real say in decisions may not win support (Crawford et al. 2022)
End-of-life responsibility	Removable foundations, less digging, funded decommissioning	Toward. Every graded acre is soil somebody has to rebuild later
Agricultural production	Clearance for a tractor, room to turn, something worth growing underneath	Both. It is why there are sheep under the panels, and why there is no prairie
Grid and market demands	The power contract, the renewable-energy credits, a grid connection the queue will deliver	Both. A buyer’s scorecard can plant habitat on a thousand sites, or lock the wrong seed mix into all of them
Policy and permission	The permitting path, prime-farmland and setback rules, and the subsidies that decide what pays	Both. California’s groundwater law pays a grower to retire irrigated ground. Iowa’s ethanol mandate pays a grower to keep planting it
Operations and maintenance	Cover that is simple to mow, or gravel that never grows, for thirty years	Away, then toward. Natives cost more for the first three to five years, then less to mow (McCall et al. 2023)
Energy yield	Panels packed close, tilted to the sun, low, and edge to edge	Away, though plants underneath keep modules cooler and cool modules make more power (Merheb et al. 2025)
Cost and financing	Standard racking, simple rectangles, and a project big enough to raise money against	Away. Anything unusual costs more, and the paperwork does not shrink with the project. It changes sides where the restorative choice is also the cheap one, such as moving less earth

Go deeper

• Design import
  Carrying a solution into a region where it was never shown to work, like Southwest shade into the Midwest.
• Diffuse fraction
  Why cloudy regions send more light under the panels, and why that weakens the case for tracking.
• A misquoted grazing cost
  A sheep-grazing cost now in circulation is really a mowing cost. Grazing itself ran about $50 an acre a year.
• Prime farmland
  A USDA soil class, and the one term in this glossary that can stop a project by itself.

Crawford, Jessica, Douglas Bessette, and Sarah B. Mills. 2022. “Rallying the Anti-Crowd: Organized Opposition, Democratic Deficit, and a Potential Social Gap in Large-Scale Solar Energy.” Energy Research & Social Science 90: 102597. https://doi.org/10.1016/j.erss.2022.102597.

McCall, James, James Macdonald, Robin Burton, and Jordan Macknick. 2023. “Vegetation Management Cost and Maintenance Implications of Different Ground Covers at Utility-Scale Solar Sites.” Sustainability 15 (7): 5895. https://doi.org/10.3390/su15075895.

Merheb, Caroline, Jordan Macknick, Nicholas Davatzes, and Sujith Ravi. 2025. “Synergies and Trade-Offs of Multi-Use Solar Landscapes.” Nature Sustainability 8: 857–70. https://doi.org/10.1038/s41893-025-01600-1.