From IoT to Green Roofs: Shenzhen’s Smart City Success and the Unequal Future

Shenzhen, China’s most celebrated “model smart city,” has become the stage for a striking experiment in digital sustainability, with researchers from the School of New Media Art and Design at Beijing University of Aeronautics and Astronautics examining how advanced technologies such as the Internet of Things (IoT) and artificial intelligence (AI) are reshaping urban planning. Their new study, published in Sustainable Futures (2025), offers a sweeping account of Shenzhen’s push to integrate smart technologies into everyday city management between 2020 and 2023. The results are impressive, demonstrating energy savings, cleaner air, and stronger flood resilience. Yet the researchers also find troubling inequities and governance gaps that temper the success story, highlighting the dangers of a purely technocratic approach to sustainability.

Smart Grids and Renewable Ambitions

The study identifies four flagship initiatives driving Shenzhen’s transformation. The first is the creation of smart grids and renewable energy integration, enabled by 2.1 million smart meters and more than 50,000 IoT sensors. This system allowed the city to trim electricity consumption by 15 percent, equivalent to 1.6 terawatt-hours annually, while offshore wind projects and blockchain-powered microgrids boosted renewable adoption. The Fujian District’s microgrid, combining solar, wind, and battery storage, reached 90 percent self-sufficiency during non-peak hours. Financially, the city invested $2.8 billion in smart grids, reaping $420 million in annual savings, though the researchers note subsidies for low-income households amounted to a mere 0.4 percent of total investment, leaving poorer families excluded from solar leasing programs.

Reinventing Mobility with AI and EVs

The second major initiative centers on mobility. Shenzhen electrified its entire public bus fleet and achieved a 94 percent electrification rate for taxis, making it the world’s undisputed leader in public EV adoption. AI traffic management systems powered by Tencent further optimized mobility, reducing congestion by nearly 30 percent in some districts and cutting transport-related emissions by 20 percent between 2020 and 2023. Accident rates for autonomous shuttles fell dramatically compared to conventional vehicles, underscoring the safety potential of automation. Yet beneath these headline achievements lurk structural challenges. An e-waste crisis looms as 12,000 tons of EV batteries were retired in 2023 alone, only 35 percent of which were recycled. Algorithmic bias in AI traffic systems worsened inequities, as commercial corridors received priority, lengthening commute times in suburban districts by nearly 20 percent. Moreover, while 80,000 public charging stations were deployed, most were clustered in higher-income zones, leaving working-class neighborhoods underserved.

Sponge Cities and Flood Resilience

The third innovation, sponge city infrastructure, seeks to address Shenzhen’s vulnerability to flooding. The program rolled out permeable pavements, rain gardens, and modular flood-absorbing surfaces designed to manage heavy rainfall in a city that faces seasonal typhoons. Supported by AI-based forecasting systems, which achieved 92 percent accuracy during Typhoon Saola in 2023, the initiative reduced flood incidents in Fujian District from eleven in 2019 to just two in 2023. Economic losses from flooding fell from $220 million in 2020 to $90 million in 2023, illustrating the financial wisdom of preventive planning. However, the study notes that permeable pavements cost $65 per square meter compared with $45 for traditional concrete, creating barriers to widespread use in poorer districts such as Longgang. While modular designs could help scale solutions to other flood-prone megacities like Jakarta, the cost remains a sticking point.

Vertical Greening and Its Price Tag

The fourth initiative focuses on vertical greening, with skyscrapers and rooftops covered in vegetation to reduce heat island effects and absorb pollutants. Between 2020 and 2023, vertical gardens grew from 1.2 to 3.4 million square meters, and green roofs nearly tripled in scale. These additions correlated with a 22 percent improvement in Shenzhen’s Air Quality Index, while smart irrigation sensors cut water use by more than half. In dense urban centers, average surface temperatures dropped by up to four degrees Celsius. Yet the benefits came with steep maintenance costs, about $120 per square meter for retrofits and $25 per square meter annually for upkeep, far beyond the means of low-income communities. Public opinion surveys reflected this tension, with 88 percent praising aesthetic improvements but only 42 percent supporting the financial burden of maintenance.

Global Lessons and Future Pathways

Taken together, the results present a double-edged narrative. Shenzhen’s aggressive use of technology delivered measurable environmental gains, from a 15 percent reduction in energy consumption to a 30 percent expansion of green cover. But the advantages are unevenly shared. Only 12 percent of low-income households could access electric vehicle leasing programs, compared with more than 60 percent of affluent families. Most vertical gardens and charging stations were concentrated in wealthy districts such as Nanshan and Futian, leaving marginalized groups excluded. Elderly residents struggled with digital tools like smart meters, deepening the city’s digital divide. The research warns that Shenzhen risks a form of “green gentrification,” in which eco-friendly infrastructure enhances life for elites while pushing disadvantaged communities further to the margins.

International comparisons reveal both strengths and weaknesses. Shenzhen outpaces Singapore and Barcelona in public EV adoption, but lags behind Copenhagen in renewable energy and inclusive policy design. Where European cities embed equity considerations, Shenzhen’s centralized model prioritizes speed and scale at the cost of fairness. Public-private partnerships, like the collaboration with Tencent on AI traffic management, proved critical for success, yet the absence of mandatory recycling regulations hampered progress on battery waste. Surveillance-enabled environmental sensors triggered public backlash, exposing ethical tensions in data governance.

The authors conclude that technology alone cannot secure a sustainable urban future. They recommend three policy priorities: equitable financing, such as subsidies that halve retrofit costs in poor districts; robust data governance, including anonymized IoT protocols and community oversight boards; and replicability frameworks like modular sponge city kits tailored for flood-prone regions. Shenzhen’s achievements show what is possible when digital innovation is applied at scale, but its shortcomings underscore that sustainability must also be about justice. As cities worldwide confront climate urgency, the lesson from Shenzhen is clear: smart city technologies can indeed green the metropolis, but unless equity and governance are at the center, their promise will remain unevenly fulfilled.