Diesel buses—and the choking smog they spew—are a common sight in most cities. But not in Shenzhen, China.

The southeastern city, which connects Hong Kong to mainland China,宣布at the end of last year that all of its16,359buses had gone electric. The city’s buses are the world’s first 100 percent electrified bus fleet, and its largest—bigger than New York’s, Los Angeles’s, New Jersey’s, Chicago’s and Toronto’s electric bus fleetscombined.

这座城市如何克服诸如高成本，缺乏充电站基础设施等障碍，为其他希望使公交线路电气化的城市提供了教训。

电子停留的成本和收益

Diesel buses may comprise a small percentage of the vehicles on city roads, but they create an outsized environmental impact. In Shenzhen, diesel buses represent 0.5 percent of a city’s total vehicle fleet, but account for20％它的运输排放量是因为它们的运行时间更长，并且驾驶比私人汽车更多的行驶里程。

因此，切换到电动巴士为通往清洁空气的重要道路。世界各地的城市和州，例如London和California, are pursuing e-buses as a way to meet their air quality goals.

Yet shifting from diesel to e-buses isn’t easy. Electric buses cost 2 to 4 times1比传统的柴油巴士更美好。他们需要基础架构来支持一致的充电。而且他们的电池在其一生中至少需要一次更换一次，这可能是昂贵的。更换电池几乎是车辆价格的一半。

Electric charging stations for buses in Shenzhen, China. Photo by Lu Lu/WRI China
Electric charging stations for buses in Shenzhen, China. Photo by Lu Lu/WRI China

Shenzhen: The Making of the World’s Largest E-Bus Fleet

然而，深圳仍然能够使其公共汽车具有成本效益。四个策略帮助：

1. National and local subsidies

对于深圳和许多中国城市而言，国家和地方补贴等政策激励措施在缩小电子车与常规柴油巴士之间的成本差距方面起着重要作用。在2016年之前，深圳为12米的E-BUSreceiveda$ 150,000政府补贴，超过一半的车辆价格。

Yet some studies show that subsidies may not be necessary to make e-buses cost-competitive with diesel buses. According to a study conducted by the World Bank and Global Environment Facility,2the lifecycle cost of e-buses in Shenzhen as of 2016 (including procurement, energy and maintenance costs over an eight-year period)3为$ 375,457，几乎与柴油巴士的终生成本相同342,855。简而言之，虽然深圳的电子代码的前期成本很高，但其运营和维护成本大大低于柴油巴士。

2. Leases to reduce upfront investments

Instead of directly procuring e-buses at the subsidized prices (around $90,000-$120,000) like many other Chinese cities, some bus operators in Shenzhen lease vehicles from manufacturers. This greatly saved operators’ upfront investments, and reduced the need for debt financing.

3.优化充电和操作

Operating an e-bus fleet differs significantly from operating a diesel fleet. Due to shorter driving ranges and recharging needs, Chinese cities typically require 100 percent more e-buses than conventional diesel buses. This requires additional money for procurement, operations and maintenance. Shenzhen almost entirely wiped out these additional costs by optimizing its operations and charging.

Shenzhen adopted a type of e-bus where afive-hour charge supports 250 kilometers (155 miles) of driving, almost sustaininga full day of operation.但是，为了确保充电不会破坏公交服务，公交运营商与收费基础设施提供商合作，为大多数巴士路线提供充电设施的设施；当前，充电插座与电子总数的比率为1：34. The charging facilities are also open to private cars, thereby improving the financial performance of the charging infrastructure.

公共汽车运营商还协调了与运营计划的充电时间，当电价低时，所有电子车都在一夜之间充满了充电，并在非高峰旅行时间期间在航站楼充电。

4.终身保修电池

E-Buses的早期技术不成熟，再加上中期电池的更换需求，通常会导致频繁的机械故障和成本增加。传统上，公交运营商承担所有这些费用，但是在深圳，公交制造商为车辆和电池提供了终身保修，因为公交运营商在采购阶段需要此保修。

Manufacturers are better positioned than bus operators to manage financial risks because they can continuously innovate battery technologies.

通过更好的公共汽车更好的城市

Shenzhen’s experience proves that it’s possible for cities to cost-effectively electrify their bus fleets. The result benefits citizens both on and off the bus: Shenzhen met its air quality improvement goals in both2016 and 2017.

1Shenzhen Urban Transport Planning & Design Institute. 2017. New Energy Bus Operation Evaluation Framework (Stage report). World Bank-GEF “Large-city Congestion and Carbon Reduction” Project

2Shenzhen Urban Transport Planning & Design Institute. 2017. New Energy Bus Operation Evaluation Framework (Stage report). World Bank-GEF “Large-city Congestion and Carbon Reduction” Project

3The lifecycle cost refers to providing the same level of service (including mileage and frequencies) as a diesel bus, the number of e-buses and the pertinent investments (including procurement and O&M) required.

4Shenzhen Urban Transport Planning & Design Institute. 2017. New Energy Bus Operation Evaluation Framework (Stage report). World Bank-GEF “Large-city Congestion and Carbon Reduction” Project