Seven billion. That’s the estimated number of elevator journeys taken each day. Elevators are an invisible yet integral part of our increasingly vertical urban culture. And yet the efficiency of this building component is often overlooked.
Elevators often weigh upwards of 80,000 pounds. Lifting and lowering that amount of mass multiple times every hour requires a significant amount of energy. In fact, research shows that elevators can account for 2 to 10% of a building’s energy usage.
Contemporary elevators are being designed to meet increasingly exigent building efficiency and sustainability goals. While energy-efficient design features such as LED lights and recycled or sustainable construction materials are increasingly common, some elevator companies have also begun to explore more innovative alternatives to traditional systems.
One such advancement is in machine-room-less (MRL) technology. By eliminating the need for a specialized room to house machinery, hydraulic oil, and pumps, room-less elevators conserve both vertical and horizontal space. Building managers explain that the space (in some structures located near the rooftop) can be repurposed for solar panels and/or rooftop gardens.
Elevators sit idle for long periods of time, but they must be dispatchable at a moment’s notice. In order to be ready for passengers at all times, their systems require energy even while not in use. Otis Elevator devised a system of destination dispatching in an effort to reduce wasted energy and improve efficiency. The system organizes trips by destination to optimize energy usage and removes elevators from service when traffic is light. The company’s Gen2 Switch, a battery-powered elevator, enables it to utilize solar and wind power.
Elevator systems that produce energy are another advancement that is raising the bar. In 2017, Thyssenkrupp Elevator retrofitted an existing elevator in Boston’s historical district with energy generating cars that divert power back to the electrical grid to achieve net-zero energy. When it’s not in use, the system turns off all lights and the fan and powers down the drive to conserve energy. “We’re actually producing more energy than we’re consuming,” Brad Nemeth, vice president of sustainability at Thyssenkrupp Elevator Americas, told Smithsonian Magazine.
Optimizing elevator performance, and even using these building features as generation sources, could change the amount of energy buildings require, as well as the way we power them. Half the world’s population currently lives in cities—a number that the UN predicts will increase to 70% by the year 2050. Therefore it seems especially important to consider the efficiency of our intra-building transportation systems. Enhancing the efficiency of these systems could contribute to reductions in urban power usage. It may even influence the way we interact with the architecture around us.
What are your thoughts? Do you think that making elevators more efficient could help buildings become more sustainable? Could they support decreases in urban power requirements?