All three sources are sized to deliver the same amount of energy per year — enough for the chosen number of households at an assumed 4,000 kWh/household/year. Each source's average land use per unit of annual energy output (km² per TWh/yr) then sets its footprint:
| Source | km² / TWh·yr⁻¹ | Land character |
|---|
| Nuclear | ≈1.3 | fully dedicated site |
| Solar PV | ≈19 | fully dedicated site |
| Wind (spacing) | ≈72 | ~2–3% dedicated (pads/roads), rest dual-use |
Nuclear packs enormous continuous output into a small footprint because fission releases roughly a million times more energy per kilogram of fuel than burning anything, and the plant runs around the clock. Solar needs far more area because sunlight itself is diffuse and only arrives — at useful intensity — for part of the day. Wind's spacing footprint is largest of all because turbines must sit several rotor-diameters apart to avoid stealing each other's wind (wake interference), but unlike a solar array or a plant's fenced perimeter, nearly all of that spacing land keeps its previous use — crops still grow and cattle still graze right up to a turbine's base. Toggle "dual-use land" off to see the wind farm treated as if every hectare between turbines were as exclusively occupied as the solar array.
The three footprints are drawn strictly to scale relative to each other for the chosen target — because area (km²) is directly proportional to annual energy in this model, the ratio between the three shapes stays fixed at roughly 1 : 15 : 55 no matter what target you pick, but their absolute size on screen grows or shrinks with it.