Some called for punitive measures as well, saying their absence may prompt local governments to scale down funding and purchases of new-energy vehicles.
Both mandatory and punitive steps are necessary to activate the central government's 30 percent stipulation for new-energy vehicles in fresh purchases, according to Zhang Yu, managing director of consulting firm Automotive Foresight (Shanghai) Co Ltd.
"There have already been a lot of encouraging policies, but the development of new-energy vehicles might still need some tough measures," Zhang said.
Statistics show that China sold 108,654 new-energy vehicles in the first eight months of 2015, a 270 percent rise from the same period a year earlier. Pure electric models accounted for the majority of the rise.
The remarkable performance amid China's otherwise sluggish auto sales has attracted carmakers to put more emphasis on new-energy vehicles.
German automaker Volkswagen said earlier this year that it would locally produce 15 new-energy models in China.
Shanghai GM has released a five-year plan with new-energy vehicles one of its highlights.
Hebei-based Great Wall Motor plans to earmark more than 11 billion yuan ($1.73 billion) to develop new-energy vehicles, and it is reported that its first electric car will hit the market in early 2016.
Chongqing-headquartered Changan Automobile said it would spend 18 million yuan on new-energy vehicles and release 34 new-energy models over the next 10 years.
