With current efforts around the Paris Climate Agreement, sustainability goals are at the top of most governments' agendas. The growth of Earth's population - expected to reach 11 billion people by the end of the century - will also present numerous challenges for natural resources, space and energy, especially when we consider the majority of the population (70%) will live in cities.
In fact, cities are expected to grow by as much as a third by 2030, by which time they will also account for two thirds of global energy demand. If we consider more than 150,000 buildings are constructed in the U.S. alone each year, it's hardly surprising that buildings consume around 40% of the total energy produced globally, putting them right at the heart of the energy efficiency debate.
Perhaps surprisingly a key part of the problem lies in a legacy of inefficient building services, such as heating, ventilation and elevators. These inefficient and outdated systems are contributing to 'locked-in' energy patterns in our cities across the world.
If we consider the effects of this, in the US alone, it results in around 120 TWh (kilowatt hours) of locked-in energy consumption per year - that's the equivalent of the Netherlands' total annual electricity consumption. If we could reduce this amount by even 10% it would reduce carbon emissions by up to 180 million tons of CO₂ each year, which is the same as reducing the number of cars on the street by two million per year, or planting and growing three billion trees over the same period.
When we assessed the energy consumption of our elevator systems, we found the majority of elevators only run 20% to 30% of the time. This is what inspired us to completely change the way we think about elevator energy consumption. At the Fraunhofer Center, we went about modernizing the buildings current elevator system to create the first net-zero energy elevator. Modernization makes it possible for the elevator to go into hibernation or 'sleep mode' when idle, leading to a reduced power consumption of as much as 150%. With 12+ million elevators in operation globally, modernization solutions have far more impact than newly installed units and has the ability to reduce the energy consumption of a building by around 7%.
Energy saving solutions like moving walkways that only begin operating when a passenger approaches, and regenerative braking products in elevators, can also contribute to reducing a building's energy needs. At the new One World Trade Center in New York, the regenerative drives in the elevators supply enough energy for the building's entire lighting system. With the further implementation of innovative technologies, experts hope to be able to cut energy costs in cities by around $11BN by 2019.
As buildings multiply and climb even higher to accommodate our growing population, it's clear that we need to start looking at ways to best minimize consumption and reduce the urban energy footprint. Buildings offer endless opportunities for sustainable development - green roofing, combined heat and power and solar technology are all achievable realities for new-builds. With urban development taking off, we have a unique opportunity to improve the way that our cities are structured, making them cleaner, greener, and more cost-efficient than ever before.
With the war against climate change gathering pace, buildings are an obvious target for cities who are aiming to reduce their carbon footprints. It's crucial the choices we make today around building development are sustainable ones, to ensure we leave a lasting and positive impact, not only for our planet, but for the generations to come.