Today, transportation accounts foralmost 30%of all greenhouse gas (GHG) emissions in the United States.

好消息是，美国的乘用车以前所未有的速度充气。2018年，有100万辆电动汽车（EV）在路上，recent studies预计到2030年，将在全国各地部署大约2000万辆电动汽车。在全球范围内，到2030年，这个数字可能会超过2.5亿电动汽车。International Energy Agency (IEA).

Though EVs are two to three timesmore efficientthan conventional gasoline-powered vehicles and have no emissions at the tailpipe, the reduction in GHG emissions and overall air quality benefits they bring depend on the mix of generation sources on the grid used to charge them. In some cases, EVs could result in substantial GHG emissions or even help extend the life of fossil fuels, if charged primarily with fossil fuel-based generators.一项研究found that in China, EVs can contribute two to five times more smog than gasoline-powered vehicles, due to the country's reliance on a coal-fired grid.

Acknowledging this, several utilities, automakers, cities and EV charging providers across the U.S. are rolling out new pilot programs and services that allow residential and commercial customers to use renewable energy for their EVs electricity needs, and charge at times that help integrate more renewable energy sources on the grid. Daytime charging syncs with peak solar output, while nighttime charging can often align well with wind output. Below, we explore some of the charging options currently offered, primarily highlighting examples that look to match the timing of EV charging with renewable energy generation more closely.

网络充电

In some cases, customers can access a network of stations to charge their EVs with renewable energy. Austin Energy has developed a network charging program, called无处不在的插件网络，这使客户每月以4.17美元的价格从风中收取电力的100％，客户可以无限制地访问该市网络中800多个充电站。奥斯汀能源服务区域内约有35％的电动汽车所有者参加了该计划。此外，奥斯汀还提供了一名飞行员，该飞行员鼓励在夜间和周末在家中取消过高的充电，此外还可以进行网络充电。

今年早些时候，国家快速充电网络公司Evgo宣布了为其动力的计划EV charging network用100％的风能或太阳能。为了参与，客户可以注册按您的付费计划，该计划每分钟收费的客户或每月收取固定利率的会员计划。

Managed Charging

Through managed charging programs, customers, utilities or even automakers can control the timing of EV charging to align with clean energy availability and grid needs, while still meeting customer needs. In a pilot program called向前充电, run by Pacific Gas & Electric and BMW in April 2018, customers agreed to delay charging for up to an hour each day to better align with available renewable energy, in exchange for lower charging rates.

充电现场可再生能源

电动汽车充电可以与现场可再生能源产生配对 - 最常见的是通过与现场太阳能系统共同列持电动汽车，在某些情况下，电池（无论有或不带有管理电荷）。

从2012年开始，圣地亚哥天然气与电气与圣地亚哥市和其他演员合作实施了圣地亚哥动物园的试点项目, where 10 solar photovoltaic (PV) canopies were installed. This program gives customers access to five charging stations and, when not in use, the solar energy is stored in a battery system. Similarly, Googlealso powers a portion of the 750 charging stations designated for its employees with the solar energy generated by their own PV systems.

Discounts for Times of Peak Renewable Energy Availability

Some utilities offer discounts to customers willing to charge when renewable energy is being generated. In January 2019, Southern California Edison introduced atime-based rate这鼓励顾客在工作日和周末的非高峰时段收费，当时太阳能大量（上午8点至下午4点），然后在晚上（晚上9点至上午8点）再次充电。此费率的入学率的固定每日费用为0.40美元，并且折扣利率为每千瓦时0.13美元（千瓦时），而在高峰期的标准$ 0.27-0.38。

Electric Vehicles Are Coming. Are We Ready?

许多城市，州和公司都建立了目标，将其车队转换为电动汽车并用清洁能源为其提供动力。亚马逊最近宣布计划在2040年之前购买100,000辆电动货车，作为其承诺的一部分，而剑桥和波特兰等城市已承诺到2035年和2050年分别承诺100％可再生能力的社区范围内交通。

With this number of EVs coming online in the coming years, it is crucial that both customers and utilities continue to explore new ways to charge EVs with renewable energy sources in order to maximize emissions reductions. EV charging can also be an important source of flexible electricity demand to enable use of larger amounts of variable solar and wind energy on the grid. New utility and third-party offerings are emerging to enable customers to opt for renewable energy to meet charging needs, but these are not available everywhere---new programs and solutions must be designed to enable customers to align charging to when clean energy sources are available and offer customers savings when they provide grid benefits.

For a more in-depth view of the range of different approaches and emerging program designs currently in market, download our publication, "将可再生能源用于电动汽车需求：公用事业计划设计和实施策略的审查。”