NeAr Science Magazine

By Panagiota Paraskevopoulou

Imagine walking through a city where every step you take helps power the lights above you. Where the windows in towering skyscrapers silently generate electricity. Where the road beneath your car wirelessly charges your battery while you drive.

This isn’t a scene from a sci-fi movie, it’s already happening. Thanks to a new wave of renewable technologies, power generation is becoming invisible, ambient, and seamlessly integrated into the urban environment. Welcome to the age of invisible renewables.

While wind turbines and rooftop solar panels dominate conversations around clean energy, they’re only part of the story. Increasingly, scientists, designers, and engineers are embedding power-generating tech directly into the surfaces and infrastructure of our cities quietly, efficiently, and almost invisibly.

Windows That Generate Power

Researchers at Michigan State University (MSU) have developed transparent solar cells that capture ultraviolet and infrared light while letting visible light pass through. These see-through solar cells can be integrated into windows, smartphone screens, and even car windshields, transforming everyday surfaces into energy generators without changing how they look or function.

This technology is already at work. In Rotterdam, a building called The Crystal Houses features these next-gen solar windows, developed by Dutch company PHYSEE [2]. Known as PowerWindows, they are designed to not only generate electricity but also adjust internal lighting and temperature via built-in environmental sensors, blending renewable energy with intelligent design. PHYSEE has installed similar energy-generating windows in various projects, including a residential tower in Amsterdam. In this installation, 1,800 square meters of PowerWindows were integrated, equivalent to the energy output of 100 square meters of traditional solar panels. 

Power Beneath Your Feet

In London, commuters at West Ham tube station might not realize they’re generating electricity with every step they take, but they are. In 2012, during the London Olympics, Pavegen installed kinetic energy tiles at the tube station. Each step compresses the tile slightly, activating a flywheel that generates electricity. That power is then used to operate LED lighting and digital signage in the station. 

Building on this concept, researchers in Tokyo have explored embedding piezoelectric materials into train station floors to capture vibrations from foot traffic. Piezoelectric materials generate an electric charge when subjected to mechanical stress, such as pressure from pedestrians. 

Even sound is being explored as a form of energy to generate electricity. Along some Korean highways, noise-harvesting panels are being tested to convert ambient traffic noise into small amounts of electricity. It’s still early days, but these unconventional solutions hint at a future where every movement from footsteps, to vibrations, to different noises, can be used to harvest energy.

Charging Roads

In Tel Aviv, Israel, a company called Electron is embedding inductive charging coils beneath the asphalt of busy bus routes. As specially equipped electric vehicles drive over these roads, the coils transfer energy wirelessly to the vehicle’s battery, enabling continuous motion without the need for cables or stops, creating the first operational, public wireless Electric Road System (wERS) in the country. 

Inspired by the same concept, Detroit is now launching its own invisible energy project. Set to go live in 2025, they will be the first to build a wireless-charging road segment in the United States. If successful, this initiative could transform how we think about electric vehicle infrastructure, making charging an integrated part of the driving experience, eliminating the need for frequent charging stations.

Buildings as Batteries

In the cold north of Sweden, a research team at Chalmers University of Technology are blurring the line between construction and energy storage. They have developed a type of concrete that functions as a giant battery. By combining cement with carbon fibre and a special metal coating, typically a metal oxide, the material can store and release low-voltage electricity. 

Imagine buildings that not only consume less energy but also store it. Drawing power from rooftop solar panels or transparent windows during the day and using that stored energy to keep lights on at night. Combined with smart materials that regulate temperature and lighting, the buildings of the future won’t just be efficient, they’ll be energetically self-sufficient.

A Quiet Revolution

What makes these technologies remarkable isn’t just their ingenuity, it’s their subtlety. They don’t require people to change their behaviour or cityscapes to be redesigned from scratch. They work with the urban environment rather than against it, transforming the energy landscape one surface at a time.

As cities strive to meet ambitious climate goals and cut carbon emissions, this hidden grid could become the invisible backbone of clean urban living. From transparent solar glass to kinetic sidewalks and wireless charging roads, the city itself becomes an engine for sustainability. And perhaps that’s the most revolutionary part. Not the power itself, but the quiet, seamless way it enters our lives, where every surface, every step, every sliver of city infrastructure becomes a contributor to a cleaner, smarter future.