Shenzhen, China

A “megacity” is one populated with 10 million or more souls. You can imagine the energy needed to power, feed, and keep that many people warm or cool each day. ExxonMobil’s Energy Factor explains that in some developing megacities, governments are working hard to change their energy footprints before they become unsustainable. Here are some examples:

Shenzhen, China

Shenzhen was little more than a sleepy fishing village bordering Hong Kong when the Chinese government made it one of the country’s first Special Economic Zones in 1979. The move unlocked foreign investment, and the population skyrocketed to over 12 million. Today Shenzhen’s factories produce 90 percent of the world’s electronics, including Apple’s iPhone. All of these factories consume a lot of energy, but the local government is working with various private companies to install efficient technologies in office buildings. One of the best contemporary examples are the offices of the appropriately named Shenzhen Institute of Building Research, where natural ventilation uses 30 percent less air conditioning than a comparable building in the city, and daylight for office spaces reduces the need for artificial lighting. Moreover, the city has a program that allows building owners to use the cost savings from reduced energy consumption to pay for efficiency upgrades.

Tianjin, China

Tianjin, a walled city founded in the 15th century, has a population of 11 million. In 2005 the local government began enforcing tough new energy-efficiency building codes that include increasing heat retention in buildings during the city’s chilly winters and natural shading for Tianjin’s hot summers. According to the Energy Foundation of China, by 2020 over 75 percent of new buildings will meet energy-efficiency standards. By 2030 the local government expects over 90 percent of new buildings to be “green buildings.” Even residents of older buildings are benefitting from requirements to upgrade their insulation or heating systems. The Tianjin Housing and Urban-Rural Development Commission estimates that 60 percent of residents in an energy-efficiency pilot program paid less in heating costs than they did before the building codes went into effect.

Hyderabad, India

By 2020 Hyderabad will have 10 million inhabitants, up almost 2.5 million from its current population. This rapid growth comes with its share of challenges, including regular power outages that threaten the city’s growing IT industry. To solve their energy problems, city leaders adopted an energy-saving building code in 2012. In addition, incentives for installing rooftop solar panels adopted in 2015 cut through what was previously a stifling bureaucratic process, guaranteeing that applications for rooftop solar panels are processed in weeks.

Bangalore, India

With a thriving tech scene, Bangalore is one of the world’s fastest-growing cities. However, the city’s infrastructure is struggling to keep up with its burgeoning population, resulting in an average of over 50 power outages a day. Many in Bangalore use diesel generators as backup, but India’s Centre for Science and Environment (CSE) believes that making rooftop solar panels mandatory could help curb the use of the generators, providing another source of household electricity and improving air quality.

Onitsha, Nigeria

Few people outside of West Africa have heard of Onitsha, but the port city on the banks of the Niger River boasts a population of almost 7.5 million. Residents of this rapidly expanding city use a mix of oil, natural gas, solar, wind power and biomass to deliver energy. Onitsha is less developed than similarly sized cities in China and India, but the city’s rising middle class is hungry to make the switch to modern, energy-efficient household appliances, a change that USAID and the Nigerian Energy Support Program estimate could reduce energy consumption by as much as 40 percent.

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