As the drive for sustainable, low‑energy buildings intensifies, even the elevator, which was once considered a minor player in a building’s energy profile, is emerging as a surprising opportunity for innovation. By capturing energy that would otherwise be wasted, advanced elevator systems are becoming part of the solution to net‑zero and energy-positive buildings. Research in recent years has demonstrated that what was once purely a load-bearing component can now act as a micro‑power generator.
Capturing Energy Through Braking and Regenerative Drive Systems
Traditional elevator systems lose a substantial amount of energy through braking. When an elevator descends under heavy load, or ascends when lightly loaded, its motor acts not only as a mover but also as a generator. In legacy systems, that energy is dissipated as heat through resistors. But modern regenerative drive systems convert that motion back into usable electricity.
Academic research has shown that integrating regenerative drives can reduce energy consumption in elevators by meaningful margins. A case study of high‑rise buildings found that regeneration can yield energy savings of 15–55 percent, depending on the building’s traffic pattern, if paired with suitable energy storage devices.
How Supercapacitors and Ultracapacitors Make a Difference
Beyond just regeneration, research has explored using supercapacitors or hybrid storage systems to capture and reuse this energy. For example, a study from the University of Zagreb modelled an elevator system that uses a bank of supercapacitors to store the regenerated energy, using a bidirectional DC–DC converter.
Through simulation (verified with real elevator traffic data), the researchers showed that this setup could yield significant energy savings, tapping into regenerative power and recycling it rather than letting it go to waste.
Taking that idea a step further, researchers at Chalmers University of Technology and Sapienza University developed a hybrid energy storage system (HESS) combining ultracapacitors and batteries. Their novel control strategy allowed regenerated energy from elevator motion to be stored in ultracapacitors for immediate reuse, while excess energy charges a larger battery system. That stored energy could then be used not only for elevator drive cycles but also to power other building loads. (eg lighting or HVAC) effectively turning the elevator into a micro‑power source for the building.
Save Energy in Sleep Mode
Power savings don’t just come from regeneration. Standby or “sleep” modes are becoming increasingly smart. According to a techno‑academic report, by enabling deep sleep modes for elevator controllers and turning off cab systems (lights, ventilation) when not in use, idle power draw can be reduced drastically. In one real-world measurement, researchers found that standby power dropped by 75 percent, drastically cutting the baseline consumption when the elevator is stationary.
Size and Power Consumption
Sustainability in home elevators extends beyond energy efficiency to include the materials and power required for operation. Super slim residential elevators exemplify this approach, using lightweight components and streamlined construction to reduce the amount of metal, wiring and other materials needed.
Their efficient design not only lowers the embodied carbon associated with manufacturing but also decreases the energy required to move the cab, especially when paired with regenerative drive systems and smart control algorithms. By minimizing both material consumption and operational power use, these elevators align with net-zero and low-energy home objectives, offering an eco-conscious solution for vertical mobility in green residential buildings.
Technical Challenges that Sustainable Elevators Face
Implementing zero-energy elevator systems is not without its challenges. One technical hurdle is handling the bursts of energy that come from regeneration. During braking or unbalanced trips, the elevator can generate power in sudden peaks, which must be managed, either by feeding it back to the building or storing it temporarily in capacitors or batteries. Designing buildings to accept this energy, or to include storage systems, adds complexity and cost. Another issue is the capital cost: high-performance drive systems, energy storage devices, and smarter control electronics have a higher upfront cost, though studies (such as the Chalmers HESS project) suggest a payback when accounting for energy savings and reuse.
There are also practical challenges in retrofitting. Not every building can easily accommodate batteries or storage devices in its shaft or machine room. And maintaining sophisticated regenerative systems may require more specialized service than traditional elevator machinery.
Looking Forward
Nevertheless, the potential is too promising to ignore. The trajectory of elevator technology points toward increasingly intelligent, energy-generating systems that go well beyond current regenerative solutions. Future designs are expected to integrate ultra-efficient motors, advanced lightweight materials and sophisticated control algorithms that not only reduce energy use but actively harvest and redistribute it within the building. Researchers anticipate elevators functioning as dynamic energy nodes, using machine learning and IoT to optimize trips, store excess energy, and even feed it back into on-site renewable systems.
Other research is investigating advanced actuator designs (such as variable-impedance actuators) that regenerate energy more efficiently through smart damping schemes.
As these innovations mature, both residential and commercial elevators are likely to play a role in achieving net-zero buildings, transforming what was once merely vertical transport into a central component of sustainable infrastructure.
