Sun vector
The solar position defines the direction of incoming direct radiation for each state.
01 · The pattern
A sunflower becomes a solar field.
Each new petal advances by the golden angle of 137.508°. Repeating this rule builds a phyllotaxis field from the centre outward. A rounded four-sided polygon is stretched, oriented and gradually reduced in size, creating 8,000 individual reflector surfaces.
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Preparing the field…
The sequence determines the pattern. Solar performance determines which parts deserve to become infrastructure.
- Base polygon radius
- approximately 2.5 m
- Corner fillet
- 1.0 m to 0.4 m
- Directional stretch
- 1.8 X / 0.8 Y
- Outward scale reduction
- 1.0 to 0.4
The browser uses the actual exported boundaries, with 32 ordered points per petal. A spiral sweep reveals the exported petals from the centre outward. This display sequence keeps the built geometry intact.
02 · The method
Fixed petals. A moving sun.
Each reflector is permanently oriented toward a high central receiver containing PV cells. As the sun moves, the incidence angle changes, altering the effective reflective area and the useful solar contribution reaching the receiver.
Effective reflective area
Incidence angle and cosine response determine how much of each petal's area is useful.
Receiver contribution
Direct-normal radiation is multiplied by effective area, then reflection, atmospheric and distance losses are applied.
The solstice explorer uses 5-minute solar-position steps with hourly weather input. The sun direction changes within each hour while that hour's direct-normal radiation stays constant. Weather values are not interpolated to five minutes.
03 · Explore the field
One pattern, changing solar value.
Play or scrub through the summer and winter solstices. All 8,000 petals stay fixed while the colours follow their simulated incident radiation. Switch to receiver contribution to inspect the useful solar energy after the modelled losses.
Incident radiation on reflector
Fixed geometry · isometric viewPreparing rangeSummer · frame percentilesPreparing range
Colours use the 2nd to 98th percentiles of the selected frame. The legend updates at each time step to reveal differences between petals; colours across frames are relative to each frame's range. Inspected Wh values remain exact. North is at the upper left. The collector and solstice rails are schematic guides; drag the sun along the selected rail to change the time, or focus it and use the arrow keys. The rails illustrate seasonal geometry rather than the simulation location’s calculated solar paths.
Preparing the solstice explorer…
04 · Allocate by annual value
Keep the contribution. Reconsider the space.
This is a retrospective analytical extension of the original study. Rank the real annual per-petal results, keep the highest-ranked share, then identify the remaining elements as candidates for shade, planting, circulation or other architectural uses. This interaction proposes a selection rule; it does not present an original final allocation.
Loadingannual contribution retained
Loadingreflector area retained
Loadingreflector area released
Loadingactive reflector petals
Active reflectorReassignable / passive
Contribution retained vs material retained
Loading annual contribution…
Preparing annual allocation…
Data and interpretation
Material efficiency ranks annual useful contribution at the receiver per square metre of the actual 3D reflector surface. Absolute contribution ranks the total useful contribution of each petal. The threshold retains a chosen share of ranked petals; ties use the original petal order.
Annual project weather data covers 8,760 hours: 3,650 simulated records, 1,791 records with interpolated optical response, and 3,319 omitted nighttime hours restored as zeros. The original annual calculation interpolated optical factors between sampled hours using each missing hour's own weather radiation. This is distinct from the solstice explorer, where hourly radiation remains fixed within the hour.
The annual hourly totals reconcile with all 8,000 per-petal totals. Radiation values are preserved separately from the optional 15% PV conversion. The electricity interpretation applies that single conversion assumption to useful receiver energy; it does not add an electrical system model.
Area comes from the 32-point surface boundaries. Released area is reflector material area, not land area. Removing reflectors is an analytical selection here; mutual shading and other field interactions have not been re-simulated for the proposed allocation.
05 · Project benefit
Let performance earn the material.
Performance analysis helps determine where reflective infrastructure earns its material and spatial cost. Lower-value parts of the sunflower can remain shade, planting, circulation or other architectural uses, allowing the generative pattern to carry several roles while concentrating solar infrastructure where it contributes most.
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