The promise of smart cities is tantalizing: efficiency, sustainability, and technology at the service of human well-being. But, at the heart of this futuristic vision, beats a monumental problem. The energy supply that can sustain these technologically advanced metropolises is, at present, the great stumbling block. Solar panels that don’t work at night, expensive and limited batteries, unpredictable wind turbines and hard-to-reach nuclear reactors form a complex puzzle that still hasn’t been solved.
The energetic dream under a cloud of uncertainty
By: Gabriel E. Levy B.
Since the publication of the International Energy Agency’s (IEA) “World Energy Outlook” report in 2022, the transition to sustainable energy sources has become a central topic in urban planning.
Smart cities, designed to optimize resources and minimize emissions, depend on constant, economical and clean energy sources. However, this equation has proven to be elusive.
Solar energy, often presented as a panacea, faces significant challenges. It operates only during the day, is weather dependent, and requires large expanses of panels to supply an entire city.
According to Vaclav Smil, author of Energy and Civilization: A History, “the sun does not obey our agendas.” Wind energy, on the other hand, suffers from the same Achilles’ heel: it is intermittent and, in urban areas, its implementation becomes complicated due to space limitations and weather fluctuations.
Batteries, essential for storing energy from renewable sources, are a separate chapter. Expensive, bulky and with a limited useful life, their production generates considerable environmental impacts, from lithium extraction to final disposal.
In the face of these limitations, nuclear energy is re-emerging as a promising but controversial option. Although its carbon footprint is minimal and its production stable, initial construction costs, waste management, and adverse public perception make it difficult to adopt it on a massive scale.
Sustainability and urban planning: the challenge of balancing the scales
As smart cities emerge as models of the future, access to sufficient and sustainable energy becomes the main obstacle. According to a report by the World Economic Forum, it is expected that by 2050 70% of the world’s population will reside in urban areas. These megacities will depend on an energy grid capable of powering everything from autonomous transportation systems to sensors that monitor every aspect of urban life.
However, the challenges are formidable. In cities like New York, where the existing power grid already faces strains in times of high demand, adding the load on smart systems could be catastrophic without proper planning. In Dubai, a leader in urban innovation, massive solar parks have been a bold step, but energy storage remains an unsolved problem.
Costs, another critical factor, limit the adoption of advanced technologies in developing countries. While wealthy nations may invest in state-of-the-art nuclear reactors or advanced storage grids, states with more fragile economies struggle to maintain basic electricity systems.
A possible utopia or a nuclear illusion?
In the search for solutions, nuclear energy has returned to the debate with a renewed focus. Small modular reactors, such as those proposed by Rolls Royce, promise less initial impact on infrastructure and greater flexibility. According to studies by the World Nuclear Association, these technologies could significantly reduce urban emissions and ensure a stable supply.
However, countries such as Germany, marked by disasters such as Chernobyl and Fukushima, have chosen to completely eliminate this option from their energy matrices, prioritizing renewables despite their limitations.
On the other hand, innovations such as smart grids could optimize energy use, adjusting distribution according to demand and reducing losses. Projects such as those led by Tesla, which integrate long-lasting batteries with solar panels, offer a hopeful vision, although still expensive and limited in scale.
A telling case is that of Singapore, one of the most densely populated and technologically advanced cities in the world. Facing total dependence on energy imports, it invested in desalination systems that generate energy as a by-product and green roofs that reduce the need for weatherization.
Still, its challenge remains to find sustainable energy sources that can support its pace of growth.
In conclusion, smart cities face an uncertain future in terms of energy. As technology advances to solve storage, intermittency, and cost problems, today’s reality is that no solution is perfect or universal. The decisions we make in the coming decades will define whether these cities will be examples of sustainability or monuments to our limitations.
