Create a minimalist scientific schematic, top-view, showing why enlarging a geothermal borefield is often constrained in dense urban sites. Use three side-by-side panels on a white background. Panel 1: a rectangular urban plot with a building footprint occupying much of the site and a small available drilling area around it, with a compact borefield represented by evenly spaced boreholes. Panel 2: the same plot but with a larger required borefield for cooling-dominated operation, extending beyond the available site footprint using dashed red outlines. Panel 3: annotate the consequence: limited land availability, more drilling complexity, and impractical expansion. Use clean architectural lines, muted grey tones, and green highlights for the borefield. No photorealism, no decorative elements, only a professional academic infographic style. Mehr sehen