Many technological developments have taken place over the last 150 years, but none of it has had a greater impact than the introduction of passenger elevators. Prior to this invention, buildings were rarely up to 7 floors tall. But since the elevators have come into existence, buildings haven’t stopped growing taller and taller. In the year 2009, Burj Khalifa, the world’s tallest building was constructed with 163 floors. From the time when the first elevator was invented coming all the way up till today, we see that many major developments have taken place in the design as well as the operating systems of elevators.
    From being made of locally produced materials to becoming eco-friendly and green, elevators have come a long way. Research shows that building consume nearly 40 percent of world’s energy, and 2-10 percent of this energy is used by the elevators. The elevator manufacturers have taken these figures into consideration and are working to get these numbers down.
      Moving on to green elevators. The first question that comes to our mind when we read about green elevators is that what actually makes an elevator green? The key answer is lower energy consumption, but it’s only the start. The technologies, processes, and materials used in manufacturing these elevators also count, and so do the choices of flooring, paints, lighting, HVAC systems, and control panels. All these elements contribute in making an elevator green.
        Following are the major design and technology elements that elevator companies are using to manufacture green elevators:
          • Machine-Room-Less (MRL) Technology
              MRL technology was introduced in mid-90s and was one of the greatest developments in elevator design. Miniaturization made it possible for the manufacturers to locate the MRL machinery in the elevator shaft rather than in a machine room fixed at the rooftop of elevator. By using gearless traction design, these elevators can use almost 80 percent less energy than hydraulic elevators, without the environmental problems and expense of oil-filled hydraulic cylinders.
                KONE, Inc. was the first company to introduce MRL elevators in the market, and they became so popular and successful that the company stopped manufacturing hydraulic lifts altogether. Otis, the world-leading elevator company, have also introduced machine-room-less elevator system, also known as Gen2 system which is scalable to reduce energy consumption in a range of buildings with varying heights. The MRL elevators manufactured by the company aspire to reduce energy consumption up to 50% with additional green bonus of roller guides, gearless machine, and polyurethane coated steel belts.
                • Regenerative Drive Systems
                    Green elevators not only reduce energy consumption but also give back most of what they consume. Regenerative drive systems are responsible for recovering the energy that would usually be wasted as heat and place it back into the electrical system of the building. This technology does not only produce power for air conditioning or and lighting but it also saves considerable amount of money by minimizing the need for machine-room cooling. Regenerative drives lower power consumption during the peak time which contributes to building’s overall operational outcome. Most of the major manufacturers of elevators offer this technology.
                    • Control Features
                        Elevators without many riders require a higher amount of energy due to the difference in weight of the elevator and its counterweight. So one of the main goals of green elevators is to cut down this energy consumption due to weight differential through precise traffic control and management of other energy-consuming factors like interior lighting etc. Novel computerize systems are responsible for minimizing the number of light-load trips and ensuring that enough elevators are in operation for the users. They make sure that the service of elevators is fast enough so that the users don’t have to wait long. The system controls and monitors the amount of power delivered to the motor and ensures that the correct current level is provided to keep the motor running at its full speed. By doing so, the risk of sudden power surges, peak over-currents, and potential overload on the motor is mitigated.
                        Due to the introduction of these advanced technologies and software, we are able to build sustainable, energy-efficient, and safer elevators today, which are not only beneficial for us but also our environment. The green elevator technology might not be so prevalent today, but it’s on the way up for sure.