1  Design Levers

Designing a solar array means making a long list of choices, and almost all of them fall into six groups: how much ground to take, which ground, what to build on it, what grows there and how the place is run, who owns it, and what everyone signs. These are the design levers, the choices designers have for shaping an array. Design levers do both design work, setting the form of the array, and restorative work, setting its impact. This chapter reads them for their design work, and Chapter 5 for their restorative work. Every other scheme in this lexicon describes either what pushes on the levers or what their settings produce. Table 1.1, at the end of the chapter, lists what each lever decides and what it can deliver.

Figure 1.1: The six design levers. Six sliders on a rail, each with its design work, what it decides, and its restorative work, what it can deliver, underneath: scale on its own behind a rule, then siting, structure, and management, then ownership and contracts. The handles sit at different heights because a lever is something that gets set. Where each one sits here is arbitrary and describes no particular project.

1.1 Three kinds of lever

Scale comes first because it limits every other lever, deciding how much room the other five have, and that is why it gets a chapter of its own (§3). Its own restorative work is easy to miss. No field gets repaired because a project is 40 acres instead of 400, but a small array’s edges reach more of the fields around it, and its lease lands on more farms (§5.1). Siting, structure, and management are the physical levers. They act on the ground, and how much they can do depends on how much ground there is to act on.

Each physical lever works on a different clock. Siting is the most powerful of the six where a designer still has it, and the first to disappear as projects grow. Structure is fixed on the day the array is built, and it decides more than it appears to. A racking system chosen on cost can set a site’s soil carbon for thirty years, by deciding how much earth gets moved, before anyone picks a seed mix. Management is the only lever that can still change after the array is built, which cuts both ways. A planting that was right in year one can be mowed out in year four by a contractor following the maintenance schedule to the letter.

1.2 Ownership and contracts

Ownership and contracts are the institutional levers, and ground does not limit them. Ownership settles who keeps what the array earns. A lease pays for the use of the ground, not a share of the power sold, so a landowner who, by some estimates, earns three to four times what most crops return per acre is still being paid for land (Sturchio et al. 2025). The gap depends on the crop, and it is widest where the crop is worth least. Whether a project is restorative depends partly on who owns it, and a generous lease does not settle that question.

Contracts are what make the other levers last, because the levers are fixed at different times. Scale and siting are settled once. Structure is fixed at construction, ownership changes hands over decades, and management can change next season. Stewart Brand (1994) argues that a building works when its fast-changing layers can move without tearing the slow ones. Here management is the fast layer, and so the fragile one. Choosing a seed mix is a management decision. Whether that planting survives to year twenty is a lease question.

Two things look like levers and are not. What a project is aiming at is a goal, and what the ordinance requires is not chosen by anyone building the project, so both are pressures (§2).

TipAt Rabbit Hills

All six levers can be read from the public record. Scale is 1.4 megawatts on about six acres. Siting put the array on a pasture the university’s sheep already grazed. Structure is an ordinary layout: panels 1.1 meters off the ground at their lowest edge, in rows 6 meters apart. Management kept the flock grazing underneath. Ownership sits with the developer that built the array, SolarCity, now part of Tesla, rather than with the university. Contracts carry the rest, since the university leases the ground to the array’s owner and buys its power for less than the local utility charges.

1.3 The six levers in detail

Table 1.1: The six design levers: the design work each does, and the restorative work it can do. Scale also sets the frame for the other five. The three below it are physical and limited by how much ground there is. The two institutional levers are not.
Lever Design work: what it decides Restorative work: what it can deliver
Scale how much ground the project takes · the capacity it is filed at, and the zone that follows · interconnection, from behind-the-meter to transmission · whether to build once or phase several arrays reach past the fence, and a lease for more hosts, when the capacity is divided among small arrays
Siting which ground the array takes, and where on the parcel · whether it stands upslope or downslope of the problem it might fix · how near it is to the fields it might serve water quality, habitat context, service to nearby fields
Structure mounting type and clearance · row spacing and ground coverage · module technology · grading and site works · the built half of the edge: setback, berm, fence microclimate, room to farm, light to the ground layer
Management the ground layer and how it is established · the mowing and grazing calendar · stocking density · construction sequencing and traffic lanes · the planted half of the edge: hedgerow, buffer, screening soil and carbon, habitat, most of the water balance
Ownership who holds the asset: owner-operator, landowner, developer, utility, cooperative, or shared · an equity stake in place of a rent a share of the power revenue for the people on the ground
Contracts lease terms and duration · who buys the power (offtake) · the community-benefit instruments · the decommissioning bond the community function, and durability for everything above

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