Our area just picked up a few Proterra electric buses for use in the Catbus system, which serves Clemson University and the surrounding areas. There were some huge federal grants involved, and they have been riddled with problems, but have finally started running and carrying passengers. We're mostly a rural area and the bus system is free for all to use - paid for by Clemson University student fees and some taxpayer money from surrounding municipalities (Cities of Clemson, Seneca, Pendleton, and Central, afaik).
The buses are neat. They use overhead inductive chargers that are located at various places around town. I haven't ridden one yet (I prefer to get around by bicycle), but I hear they're pretty nice.
I am sure the impact on air quality is almost unmeasurable in our vast expanse of rural countryside, but in cities the impact could be huge.