3 The Scale Transect

Somebody chose five megawatts rather than eighty. It was decided early, on grounds of interconnection and capital, probably before anyone walked the ground, and it set the limits on every choice the design had left. That decision is scale, the first of the six levers. It is how large the array is, and so how much ground it takes, and it is the lever most often mistaken for a fact about a site rather than something a person decided.

Scale gets a chapter because so much changes along with it. As projects get bigger, a lot shifts at once:

how the array connects to the grid: behind the meter, then the local distribution line, then transmission
who decides: one landowner, then several parties at a table, then a utility with a place in the interconnection queue
what it takes to permit: allowed by right, then site plan review, then full environmental review
who manages the ground: existing farm labor, then crews hired for the site, then an outside contractor
where the money comes from: the owner’s pocket, then tax equity and a power contract, then project finance

They shift together closely enough that knowing where a project sits on the range tells you a great deal about it at once. That range is the scale transect.

Figure 3.1: Scale Transect Zones. A0 through A5, one view each, from a barn roof to quarter section after quarter section. Each view is at its own scale, given at its top left. What grows across the set is the ground in view, while the same farm, with its red barn, shrinks from the foreground to a speck.

3.1 The five zones

The zones are calibration points on that range, in the sense urban planning’s rural-to-urban transect uses the term: named places to stand, not boxes with walls. A 4 MW project and a 6 MW project differ by less than their labels suggest, and a project near a boundary should be read as sitting near one. Table 3.1, at the end of the chapter, gives each zone’s capacity, footprint, grid connection, decision-makers, and ground management.

Capacity is how a project is filed. Acreage is how the people living with it experience it, and when the two numbers disagree, acreage is the better guide, because trackers and the extra clearance of agrivoltaic layouts use more land per megawatt (Koch et al. 2025). Arrays on buildings are A0 — Rooftop. They take no ground, so they sit at the starting point of the range rather than on it. At the other end, A5 has no upper limit.

Not every zone exists everywhere. A3 tends to be common where a state runs a community-solar program and rare where it does not, because the grid and the state, not the land, decide whether a mid-sized project can sell its power. Latitude moves the footprints too: farther north, rows sit wider apart against the low sun, so the same megawatts take more ground.

3.2 Scale decides who holds the other levers

Choosing five megawatts over eighty plants nothing and commits no one to anything. A small array does some restorative work of its own, at its edges (§5.1). The larger effect of the choice is deciding which of the other five levers a designer can still reach by the time the layout is drawn. Scale is the master lever because it is settled before anyone reaches for the others, and very little later in a project wins back what it closed off.

The ground itself shows how. At the farmstead the operator holds the whole decision and has almost nothing to choose among, since one spot in the yard may be the only spot. At A3 a developer and a landowner can walk the field together and put the array on the wet low spot that never yields. By A4 the ground is usually chosen by whatever acreage could be assembled near a substation with a place in the queue (§5.2). The other levers travel the same way. Racking at A1 is whatever a local installer can find for one yard, and at A5 it is a catalog item bought by the megawatt. Ownership moves furthest: one person at the farmstead, and an investor, a landowner, and a county board by A5. Every lever survives the trip. None stays in the same hands.

At Rabbit Hills

Its 1.4 megawatts on about six acres put Rabbit Hills in A3, the community zone, at the small end of the zone’s acreage. At that size the array fits on a single pasture that one landowner already managed, and the university could go on grazing it with its own flock.

3.3 The five zones in detail

Table 3.1: The five zones, and the attributes that move together along them. The bands fit the US Midwest and should be redrawn elsewhere.

Zone	Indicative capacity	Indicative footprint	Interconnection	Decision unit	Ground-layer management
A1 — Farmstead	<100 kW	under ~1 acre	Behind-the-meter, net metered	Single owner-operator	Existing farm labor and equipment
A2 — Commercial	100 kW–1 MW	~0.5–8 acres	Behind-meter to distribution	Landowner, possibly one lease counterparty	Existing equipment, modest adaptation
A3 — Community	1–5 MW	~6–30 acres	Distribution; community solar, mid-market power contract	Multi-party: landowner, developer, power buyer, tax equity	Purpose-built: dedicated mowing, contract grazing, seeded establishment
A4 — Utility	5–50 MW	~30–300 acres	Distribution to sub-transmission; queue position matters	Developer-led, institutional capital	Contract enterprise: commercial graziers, habitat contracts
A5 — Complex	50 MW+	~300 acres to 10,000+	Transmission; merchant or utility power contract	Utility or independent power producer, several jurisdictions	Contract enterprise at ranch scale; rotation across sites

Go deeper

A4 — Utility
The widest zone. It may split at 20 to 25 MW, where several states take siting away from local boards.
A5 — Complex
No upper limit. Often several arrays on separate parcels, run as one project.
The prime-farmland argument
Towns grew up on good soil, so arrays built near where power is used end up on it.
Grazing across the transect
Who grazes at each zone and what it costs, from a farm’s own flock to contract graziers.