Ground broke on September 8, 2006, and construction finished in March 2011. The completed building rises 309.6 meters across 71 stories in Tianhe District, and its primary tenant is the China National Tobacco Corporation. That occupant is, at minimum, an irony — the most energy-efficient supertall office building in the world, according to its designers at Skidmore, Owings and Merrill, houses a state tobacco company. The tower's design follows four organizing principles: reduction, absorption, reclamation, and generation. Reduction means using less energy to begin with — through radiant cooling, demand-controlled ventilation, high-performance glazing, and daylight-responsive controls that dim artificial lights when sun fills the floor plates. Absorption captures what the environment freely offers: wind and daylight. Reclamation recovers heat from exhaust air. Generation produces clean power on-site. All four run simultaneously, and the result is a building that uses roughly 42 percent of the energy a conventional tower of its floor area would require — a 58 percent reduction.

The Pearl River Tower was originally conceived as a positive-energy building — one that generates more electricity than it consumes and sells the surplus back to the grid. The embedded wind turbines, designed to produce up to 15 times the output of freestanding turbines of the same size by concentrating airflow through the building's sculpted openings, were central to that ambition. So were rooftop microturbines that would handle on-site generation after hours. The math worked. The engineering worked. Then the local power company said no. Guangzhou's grid operator does not permit independent energy producers to sell electricity back to the network. Without the financial return from surplus power, the developers removed the microturbines from the final design. The four wind turbines in the building's body remain, generating power for the building itself. The four large notches in the tower's silhouette — arresting and slightly strange-looking from street level — are the visible evidence of an ambition that was partly accomplished and partly stopped by regulation.

The Pearl River Tower's skin is one of its most sophisticated components. A double-skin facade — two layers of glazing separated by a ventilation corridor — runs along the broad faces of the building. The outer skin admits solar heat; the inner skin blocks it from reaching the interior. Hot air rising between the two skins creates natural ventilation without mechanical assistance. Daylight-responsive blinds on the exterior open or close automatically depending on current lighting conditions, maximizing natural illumination while preventing glare. Photovoltaic cells integrated into the shading system absorb solar energy throughout the day. The effect is a building that continuously adjusts to conditions — darker in glare, more open to light when clouds arrive, always managing the boundary between outside and inside more precisely than a conventional curtain wall. A 2008 report to the Council on Tall Buildings and Urban Habitat calculated that the sustainable design features would yield a 58 percent reduction in energy use compared to a similar standalone building.

The Pearl River Tower stands in Zhujiang New Town, the planned business district that Guangzhou developed through the 2000s along the river's north bank. From street level it reads as a slender, slightly compressed slab — distinctive mainly for the notched openings that betray its wind-harvesting intentions. At skyline scale, it competes with the Canton Tower's more flamboyant hyperboloid lattice a few kilometers to the south, but the two buildings represent different ideas about what a 21st-century Chinese city should say. The Canton Tower broadcasts spectacle; the Pearl River Tower makes a quieter argument about efficiency. Together they make Guangzhou's skyline one of the more conceptually varied in China. The tower is also, the source articles note, an example of China's stated goal of reducing the intensity of carbon dioxide emissions per unit of GDP. That policy framing may be institutional, but the building that resulted from it is real, and it works.