A passive microclimate, built from the landscape.

An earth berm with an elliptical plan and a curved north profile. Not a greenhouse. Not a tunnel. An open, landscape-based structure that changes the microclimatic conditions for outdoor cultivation.

Inside the sheltered zone: open-field root crops, brassicas and berries in raised beds, polytunnels and open ground.

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Ilua system overview showing greenhouse, microclimate and light-and-energy systems together — System overview: greenhouse, Sunyard microclimate and light-and-energy systems working together.

The mechanism

Thermal mass, shelter, solar gain.

The dark inner wall of the berm (dark earth or crushed stone — high thermal mass, low cost) absorbs solar energy during the day and releases it gradually as long-wave radiation in the hours after sunset — exactly when plants are most exposed to frost. The geometry of the berm also creates shelter, reducing wind by at least 50%.

Ilua Sunyard is applied basic research. Individual elements — windbreaks, sun-traps, fruit walls and earth-sheltered gardens — are well known. The systematic design of an integrated landscape-based microclimate for Arctic and sub-Arctic cultivation is the new work.

We are building the first generation of that work openly, so others can inspect it, test it and extend it.

At 61°N this is essential, not optional. The difference between plant survival and frost death is 1–2 degrees.

Ilua Sunyard concept board with plan, section and microclimate principles — Ilua Sunyard concept board: geometry, shelter and microclimate principles.

Expected effect

What the model predicts.

Thermal model v4.0 — simulation data, audit-approved.

~2°CAnnual mean temperature gain in the near-wall zone

~15°CMaximum gain above ambient (best days)

+27 daysExtra growing days per season

+296 GDDGrowing degree days, base 5°C

≥50%Wind reduction (CFD-documented)

Status

Where the work stands.

Concept lockedThermal model v4.0 completeField validation: from 1 Jul 2026

Concept phase complete · parametric study V29 selected as final design (April 2026). Thermal model v4.0 complete and audit-approved. Field validation begins after Phase 1 start (1 July 2026).

Help fund the field validation

From model to measured reality.

Phase 1 covers final detail design and the first prototype build. Field measurements begin July 2026 — every contribution shortens the runway.

Support Ilua Sunyard validation