Portable, not permanent
Professional grazing projects almost never involve permanent fence installation. Instead, herders use rolls of portable electric netting — a mesh of polywire strung with vertical step-in posts, powered by a battery, solar panel, or small charger — that can be set up around a cell in under an hour and moved as the project progresses. That's what makes it practical to fence a new section of a property daily rather than fencing the whole site once.
The netting delivers a brief, safe electric pulse rather than a continuous current — enough to condition animals to respect the fence line (usually within their first exposure to it) without causing harm. Most goats, once conditioned as kids, respect electric netting even when the charger is briefly off.
What it's good at, and where it needs backup
Electric netting excels at flexible, temporary containment on land that would be impractical to fence permanently — a hillside, a vacant lot, an open-space parcel. It also does double duty as predator deterrence, since the same pulse that keeps goats in also discourages coyotes from crossing it.
It performs worse on very steep or rocky terrain where posts can't seat firmly, near heavy public foot traffic (which requires clear signage and access planning), and in wet or snowy conditions that can ground out a charge. Professional herders plan fence placement and daily checks around exactly these limits — which is part of why herding, not fencing, is the actual skill being paid for.