From Colombia to Argentina, major cities in Latin America are starting to adopt electric bus fleets. In a region with the highest use of buses per person globally, officials believe the transition will help meet climate targets, cut fuel costs, and improve air quality.

In Medellín, Colombia, passengers cram aboard a battery-powered bus during the morning commute. Inside, the vehicle is a respite from the crush of cars, taxis, and motorcycles winding through traffic outside. The driver, Robinson López Rivera, steers the bus up a steep ramp, revealing views of hillsides covered with rooftops of tile and tin. The bus dashboard indicates that the batteries are mostly charged, with enough power to last through the evening rush hour. “It’s a little smoother and more comfortable to drive. And there’s hardly any noise,” López Rivera says from behind the wheel. He gently brakes as a street vendor pushes a fruit cart across the dedicated bus lane. At night, the bus will return to a parking lot by the airport, recharging its 360-kilowatt battery pack while the city sleeps. The other 77 buses in the city’s bus rapid transit system, called Metroplús, run on natural gas and move about 251,000 passengers daily. Thousands more privately owned coaches and minibuses burn diesel as they traverse the sprawling metropolitan area of 3.7 million people, with older models leaving a trail of sour-smelling smoke. Faced with chronic air pollution and concerns about climate change, Medellín is now trying to move quickly to electrify its entire mass transit network. Metroplús launched its first electric bus in April 2018. Another 64 battery-powered buses will hit the streets later this year, having recently arrived on a ship from Shanghai. The new units will make Medellín the second-largest electric bus fleet in Latin America, after Santiago, Chile.

Analysts forecast that by 2025, more than 5,000 electric buses will be delivered annually to Latin American cities.

Across Latin America, city officials and transit agencies are increasingly embracing electric buses as a way to help improve air quality, reduce fuel costs, and offset rising greenhouse gas emissions. As battery prices decline globally — and as cities and national governments adopt climate change policies — electric buses are rolling out in at least a dozen urban areas, from Mexico to Argentina. In Santiago, some 200 battery-powered buses now circulate in the capital city, with 200 more slated to arrive later this year. The Chilean government aims to fully electrify public transport systems nationwide by 2040, a goal that will require deploying thousands more zero-emission buses. In Colombia, the nation’s Green Growth Commission has called for electric buses to comprise 100 percent of future municipal purchases. Bogotá’s mayor recently announced plans to buy nearly 600 electric buses for its bus rapid transit system, and the city of Cali recently purchased 26 units. Guayaquil, Ecuador’s largest city, has bought 20 battery-powered buses. The region’s fleets still represent only a small fraction of the electric buses in operation globally. Worldwide, nearly 425,000 electric buses were on the roads last year — 99 percent of them in China, where government policies to improve air quality and support manufacturers are accelerating the industry. European cities deployed some 2,245 battery-powered buses in 2018. The United States, meanwhile, had just 300, according to the research firm BloombergNEF.

Medellín will have 65 electric buses in service by the end of the year, making it the second-largest electric bus fleet in Latin America. Maria Gallucci/Yale e360

Going forward, Latin America is expected to play a bigger role in this fast-growing vehicle segment, which is projected to reach 1.3 million buses globally by 2040. Analysts forecast that by 2025, more than 5,000 electric buses will be delivered annually to Latin American cities. That’s up from 271 buses delivered in 2018. “It’s quickly becoming a global story,” said Nick Albanese, a research associate at BloombergNEF in New York. Within Latin America, Chile is expected to continue driving growth in battery-powered buses as its cities fulfill the nation’s clean transportation targets. “They’ll be a leader in the region for the next few years,” Albanese said of Chile, “and other governments will follow suit.”

Transportation is the largest and fastest-growing source of energy-related emissions in Latin America, accounting for about one-third of the region’s total carbon dioxide emissions. Private vehicle ownership is rising, while at the same time more people are moving into cities, boosting demand for buses, taxis, and motorcycles. About 80 percent of the region’s population is urbanized today; by 2050, that could climb to 90 percent, UN-Habitat predicts. Currently, an estimated 64,000 people die prematurely every year in Latin America and the Caribbean due to air pollution, caused mainly by transportation emissions, according to UN-Environment. For cities facing such challenges, urban bus fleets are a strategic place to start.

“Electric buses have a lot of complexities that diesel buses don’t,” said one official. “We’re just beginning to understand the technology here.”

Marcela Quinceno, an environmental engineer in Medellín’s Secretariat of Mobility, said the city is pursuing electrification both to address climate change and reduce the severe pollution that plagues the city during certain months. The Medellín metro area sits within “a little bowl” in the Aburrá Valley, trapping fine particulate matter and other contaminants overhead like a thick smog lid. About 80 percent of air pollution in Medellín comes from vehicles. While the the city’s natural gas-powered buses emit less pollution than diesel engines, they still result in greenhouse gas emissions. The city’s electricity, meanwhile, comes primarily from hydropower plants. “Why electricity? Because it’s zero emissions,” Quinceno said. Latin America has the highest use of buses per person globally. As municipalities work to expand public transit options into less-served areas, cleaner buses can help fill the gaps. In Medellín, the 64 new electric buses will likely operate along a central thoroughfare that’s packed with cars and private buses, but where Metroplús and public rail lines don’t reach. In Buenos Aires, which has a metro area of over 15 million people, some 18,700 diesel buses crisscross the city every day, significantly affecting air quality. City officials are adopting electric buses as part of a larger strategy to improve public transportation options, reduce climate emissions, and lower air pollution, according to Constanza Movsichoff, who manages the city’s clean mobility program. In May, Buenos Aires deployed its first two electric buses in a year-long pilot program. The data collected will help officials determine how and where to deploy more battery-powered units. “Electric buses have a lot of complexities that diesel buses don’t,” Movsichoff said. “We’re just beginning to understand the technology here.”

An electric bus charging terminal in Santiago, Chile, which draws power primarily from solar panels. Enel X

Many factors can determine how well an electric bus performs, how much it costs to operate, and whether it lives up to manufacturers’ promises. The slope of a street, the driver’s behavior behind the wheel, and extremely warm or cold temperatures can limit a battery’s range — the distance buses can travel before needed to recharge — or shorten a battery’s useful life. Some routes that work well for diesel buses might not be appropriate for new electric arrivals. In Campinas, Brazil, for instance, the lightweight aluminum bodies of early electric buses cracked when drivers took them down rugged roads. Yet if properly deployed and planned, battery-powered buses can cost substantially less to operate than diesel counterparts, experts say. Santiago’s electric buses cost about 70 Chilean pesos (10 cents) per kilometer to operate — about one-fourth the cost of diesel buses, according to Enel X, the “e-solutions” division of global energy company Enel Group. Batteries and electric motors are more energy efficient than internal combustion engines, and they generally require less maintenance. Enel X helped launch Santiago’s electric bus program in 2014 through a partnership with Metbus, the city’s bus operator, and Chinese bus maker BYD. After testing two buses on a 150-mile daily circuit, Enel X last year spent over $33 million to purchase 100 BYD buses, which it leases to Metbus, and to build electric charging terminals that draw power primarily from Chile’s solar plants. Enel X is now building more terminals in Santiago and investing in other countries, including the first electric bus in Lima, Peru, which will officially begin service in October.

For many cities, one of the biggest challenges to ditching diesel buses will be convincing private bus operators to follow suit.

“There’s no turning back,” said Simone Tripepi, who heads Enel X in South America. “We see a huge trend in the region to have electric mobility properly working in the next few years.” Significant hurdles remain to scaling up Latin America’s electric bus fleet, particularly at the pace required to meet global climate change targets. Electric buses still cost two to three times more upfront than conventional diesel buses. Electric charging infrastructure can add millions more dollars to projects. Cities must also spend to design optimal routes and train drivers and mechanics for the new vehicles. Global climate groups are starting to pitch in. C40 Cities, a collective of cities taking action on climate change, and the International Council on Clean Transportation are working with Medellín, São Paulo, and Mexico City to adopt zero-emission buses. The organizations and cities recently won $900,000 from P4G, a sustainability initiative funded by the Danish government. The Inter-American Development Bank is providing technical support, financing, and related services to accelerate clean bus adoption in Argentina, Brazil, Colombia, Costa Rica, Mexico, and Paraguay. For many cities, one of the biggest challenges to ditching diesel buses will be convincing private bus operators to follow suit.

An electric bus circulates in Buenos Aires in May as part of a yearlong pilot test. Secretary of Transportation, City of Buenos Aires

In São Paulo, contractors operate all of the city’s nearly 14,500 buses, which make some 10 million trips a day. The city recently adopted a law to make all these privately owned buses zero-emission by 2037, but many operators say they are unable to make the financial and technical commitments needed to comply. Bus ridership is already dropping in places where motorcycles or ride-hailing services are cheaper or more convenient than fragmented, inefficient bus routes. If companies have to hike fares to pay for electric buses, they risk losing more passengers, a trend that would only lead to further increases in emissions. “It’s not only about replacing [diesel] buses. You need to use this opportunity to engage cities to increase the quality of service,” said Sergio Avelleda, who was São Paulo’s secretary of mobility from 2017 to 2018, and is now urban mobility director for the WRI Ross Center for Sustainable Cities.