Solar-on-Grazing-Land Economics AU / illustrative

Land cost side. Lease rates run roughly $750–1,500/ha/year over 25–30 year terms. Grazing land beats cropping land here because sheep keep grazing under the panels (agrivoltaics) — landowners get land lease + grazing/agistment fees + wool or meat sales. A Western University (Ontario) financial study found agrivoltaic sheep-grazing EBITDA margins of 22–40%; that figure isn't Australian-specific, but Australian trials (Lightsource bp's Wellington Solar Farm, NSW) independently confirm improved wool quality under panels.

Capital / land-area side. Budget ~2–3 ha per MW (tracking is more land-efficient than fixed-tilt). Utility-scale capex is trending up, not down — global benchmarks sit around $1.25–1.85M/MW after five straight years of cost increases.

Project size sweet spot. 100–500 MW spreads fixed EPC/connection costs efficiently without hitting the diminishing returns of transmission augmentation past ~500 MW. Sub-50 MW rarely absorbs connection costs well at utility scale — but that's a different economic model to a genuinely small farm system (see below).

Small farms — no developer, you're the developer. Below roughly 1MW, third-party developer economics rarely pencil out — fixed legal, grid-connection-study and transaction costs dominate at that scale. So the "Small farm" preset removes the third-party developer entirely: there's no lease, because the farmer is both developer and landowner. Instead the model sizes a genuinely small, self-funded, behind-the-meter system directly in kW (typically 10–100kW) and values its output at what it actually saves you (avoided retail electricity, commonly 25–40c/kWh) plus a modest export feed-in tariff (mostly under 6c/kWh across Australia in 2025-26), not a PPA/wholesale price. That's usually a far better deal per MWh than exporting at wholesale — the earlier utility-scale PPA framing simply doesn't apply once the developer is out of the picture.

Grid connection reality: SWER, phases and batteries. What you can actually export depends on what's already at the property. SWER (single-wire-earth-return) lines — over 190,000km of them across rural Australia — are the most constrained, historically capped around 5kW of combined solar+battery (some networks now allow up to 10kW). Single-phase supply typically caps export around 5kW, three-phase around 15kW (up to 30kW on some networks). If your system is bigger than your connection's export limit, you've got three real options: pay for a phase/line upgrade (roughly $2,500–6,500 to go single-to-three-phase on a straightforward property; materially more — often $15k–25k+ — to move off a SWER span), add a battery to soak up the surplus for later self-use instead of exporting it, or simply accept some curtailment. The "Existing grid connection" and "Add battery storage" controls let you stress-test that tradeoff directly.

Shelter effect on the rest of the farm. Panel rows function like a shelterbelt: agrivoltaic microclimate studies measure 27.6–42.3% wind speed reduction near the array. Shelterbelt research (EverGraze/GBCMA, NZ agroforestry trials) attributes to that wind reduction: ~10–60% more pasture growth, +21% sheep / +20–30% cattle live-weight gain, ~31% (up to 43%) more wool, and roughly 10 percentage points lower lamb mortality — all from reduced cold-stress energy loss. Wind erosion within the wind-shadow can drop 24–97% (well-designed systems >80%); that's a genuine long-term soil-capital benefit but isn't monetised in the yearly figures here since erosion-avoidance value is highly site- and time-horizon-dependent. Protection reaches roughly 5–10× structure height windward and up to 30× leeward, so the benefit isn't confined to the array footprint — the "Farm productivity uplift" section lets you value that spillover into the rest of the paddock. This applies at any scale, small farm or utility.

Terrain. Flat to gently sloping (<5% grade), good soil bearing, no flood risk — which also happens to describe most Australian grazing country.

Locality. Renewable Energy Zones (NSW Central-West Orana/New England/South West, QLD SuperGrid) cut connection costs via shared transmission for utility-scale projects — but some are now oversubscribed. South-West NSW in particular is being called a "dead zone": Marginal Loss Factors have degraded (2026-27 median ~0.925) and curtailment is rising as too much generation tries to export at once. The real sweet spot is good solar resource + REZ access that isn't the most saturated zone. None of this applies to a behind-the-meter small farm system — its "locality" question is entirely about what's already on the pole outside your gate.

Grid proximity (utility/leased-land scale). Overhead transmission runs $2–4M/km, connection costs $100–300/kW. Aim for existing 132kV+ infrastructure with spare capacity within ~10–20 km — beyond that, line costs start eating the return.

Bottom line. Large Farm / Saturated REZ / Premium site: grazing land leased to a third-party developer near REZ transmission that isn't curtailment-saturated, sized 100–500 MW, run as a co-located sheep operation — the landowner collects lease + grazing income and never touches the capex risk. Small farm: no developer at all — you size a 10–100kW system to your own grid connection (and battery, if the connection can't carry it), and the return comes from avoided electricity cost plus export revenue plus the same shelter-driven productivity uplift across your paddocks. Use the presets to switch between the two models and the mode-specific inputs to stress-test either.