The following post is authored by student and Sherwood blogging intern, Rachel Gross.
One of my professors recently asked our class to think about what “grand challenges” face our society, and my mind immediately jumped to population growth and urbanization. As population continues to grow over the next several decades, resources will become more scarce and human impact on the environment will also grow. UN population studies project that world population will reach 9.31 billion by 2050. Where will these people live? Current and projected urbanization rates estimate that by 2050, about 6.25 billion people (67% of the total world population) will live in cities. This is almost twice the 2010 urban population of 3.56 billion people (about 52% of the current world population).
Cities are a huge source of anthropogenic impact on the environment. The large concentration of people in a city leads to increased air and water pollution, energy consumption, and biodiversity loss. Although cities contain half of the world’s population, they consume 60-80% of the world’s annual energy use and contribute to 75% of the world’s anthropogenic carbon dioxide emission. As cities continue to grow with population, so too will their impact on the environment. However, this impact can be mitigated through careful city planning and the creation of “green cities”. I discovered one such city during a summer internship several years ago. I was working at CH2M Hill and I got to hear a presentation about one of their projects, Masdar City. Near Abu Dhabi in the United Arab Emirates, Masdar City is a low carbon, low waste planned community of 40,000 that is going to be completed in 2025.
Masdar City was established in 2006 with the aim of becoming a world leader in renewable energy and an example of a commercially viable, sustainable city. Currently, the city consists of just 300 residents and several buildings: the Masdar Institute of Science and Technology, residences for the Institute, and some food, service, and retail outlets. All of these buildings are powered by an on-site 10 MW photovoltaic solar plant. This 22 hectare plant is the largest solar plant in the Middle East. The city will also draw on geothermal and wind energy. When the city is complete, 20% of Masdar’s energy will come from on-site renewable resources and the rest will come from renewable energy resources elsewhere in the UAE.
In addition to exclusively using renewable resources for energy, all of the buildings and the entire city itself have been designed to maximize energy efficiency. The buildings constructed in the city must adhere to strict energy-minimizing guidelines with regard to insulation, lighting, windows, smart appliances and energy meters. The city itself is oriented on a southeast-northwest axis to minimize heat gain and maximize cooling shade and breezes. The streets are fairly narrow to supply more shade from the buildings, and various water and greenery installations provide additional cooling. One of the most interesting innovations in cooling is the city’s wind tower. This 45m tower captures upper-level winds and directs them down onto the street below. The top of the tower has sensors that control the shutters that open toward the prevailing wind and close in the opposite direction to push the wind downwards. This wind tower is a high-tech version of traditional Persian “windcatchers” that date back to the 17th century. There are also windgates throughout the city to direct and regulate the flow of air on the streets. Overall, the streets of Masdar City are 15-20 °C cooler than the streets of Abu Dhabi, which is only about 10 miles away.
Masdar City’s transportation infrastructure is perhaps the largest departure from a traditional city because there are to be no petroleum-based cars in the city. The city is designed for pedestrians, with many shaded walkways. However, there will be several forms of public transportation. Right now, both electric vehicles and a personal rapid transit (PRT) system are being tested in a pilot program. The PRT system features small, fully-automated, electric “podcars” that hold two people. These podcars can travel up to 25 mph and are controlled by a sophisticated navigation system. The concept of personal rapid transit was incredible to me and I thought that Masdar City must be the first city to implement this idea. However, I found out that the PRT concept actually dates back to the 1960s and a PRT system was built in 1975 in Morgantown, West Virginia. While this concept never caught on in the 1970s, PRT is now being considered in different urban and community environments around the world. In 2010, Masdar City was the first to put a PRT system into operation, but London Heathrow airport now has PRT vehicles to take passengers to and from the parking lot and larger scale systems are being constructed in Suncheon, South Korea and Amritsar, India. Studies have shown that PRT vehicles use about a quarter of the energy per passenger per mile of a standard automobile.
The city also takes water and waste management very seriously. On a per person basis, Masdar City uses less than half of the water that an average city uses. This is achieved through the use of high efficiency appliances as well as smart meters that can detect leaks in water system. Additionally, 100% of the wastewater generated from the city is treated and reused in landscaping, which has led to huge water savings. Masdar City has also taken great efforts to manage its waste, with 96% of its construction waste reused in other ways to build the city. However, the city’s long-term landfill diversion goal is only 50%, which I thought was surprisingly low. If San Francisco can achieve 75% landfill diversion, shouldn’t a city built entirely to be green do even better?
While most people agree that Masdar City’s aims are admirable, there are some serious criticisms of the city. Originally, Masdar was marketed as a “zero-waste, carbon neutral” city, but it’s now claiming to be “low carbon” with only 50% landfill diversion. At Greenbuild, I met a sustainability consultant for Masdar City who said that he was very disappointed with how much the actual city is deviating from its original sustainable goals. He was also dissatisfied with the actual construction progress. The city was originally supposed to be completed in 2016, but that completion date has been pushed back by almost 10 years.
Despite the criticisms, I think that Masdar City represents an important step in the right direction in sustainable urban development. It is definitely on the cutting-edge of sustainability, and I look forward to seeing more cities around the world follow its lead. Masdar City is one of several green cities to start construction within the last 10 years. Other notable examples are PlanIT Valley in Portugal and Tianjin Eco-City in China. Sherwood has worked in Tianjin Eco-City, performing green infrastructure and sustainable site design services for a 350 unit residential community in the city. This project focused on water conservation and reuse due to the heavily depleted aquifer and saline soils in this area. The $10 billion eco-city is expected to be completed in 2020.