Solar Chimney Updraft Tower: Stack-Effect Power (2D)

Sky & Site

Weather condition Clear sunny day

Plant Design

Chimney height (H) 200 m

Collector area (A) 50,000 m²

Animation speed 1.0×

Live Readout

Collector Δ temp

0.0 °C

Updraft velocity

0.0 m/s

Power output

0.0 kW

Chimney radius

0.0 m

vs Manzanares (50 kW)

Turbine spin

0 rpm

How it works

A solar chimney power plant is a greenhouse collector ringing the base of a tall open tower. Sunlight heats a shallow air layer under the collector roof; that hot, less-dense air is driven up the chimney by buoyancy (the "stack effect"), and turbines at the base extract kinetic power from the draft.

Q = irradiance · A · efficiency        (absorbed solar power, W)
ΔT = Q · t_res / (ρ_air · A · h_gap · cp)   (energy balance, clamped 0–35°C)
v = 0.5 · sqrt(2 · g · H · ΔT / T_ambient)  (buoyant draft velocity, m/s)
P = 0.5 · ρ_air · π·r² · v³ · η_turbine     (extractable kinetic power, W)

Chimney radius is sized from collector area through a fixed convergence ratio, exactly as a real plant's cross-section scales with its collector footprint. The dashed marker on the power curve shows the real Manzanares, Spain prototype (~195 m chimney, ~46,000 m² collector, up to 50 kW) that these equations are calibrated against.

Cutaway — greenhouse collector (left) feeding hot air into the chimney (right); particle brightness tracks temperature.
Power curve — computed power output swept across chimney heights at the current collector area and weather, with your current setting marked live.

Cool intake air Heated updraft Power curve @ current A