Those lining up at popular tourist destinations and restaurants this year were joined by electric car owners who needed to charge their vehicles at expressway charging piles.

One EV driver complained on social media that she spent four hours at the Leiyang rest area in Hunan province on Oct 1, waiting for her turn to charge her vehicle for the one hour it needed, during her trip from Shenzhen in Guangdong province to Hunan's Hengyang.

"There were more than 20 electric cars waiting. I didn't even leave the car to go to the washroom for fear that people would cut in line," the driver said.

The driver counted herself lucky to be able to charge her vehicle after a one-hour wait on her trip back to Shenzhen on Oct 6. But recharging it took longer because the pile she used was not a fast one.

She was not alone. Statistics show that 15,668 electric cars were charged in Hunan province on Oct 3, via the State Grid network. Of them, 96 percent were done at expressway charging stations, resulting in queues of varying lengths.

State Grid statistics show that electricity consumption from Oct 1 to Oct 3 at charging stations along the country's expressway network hit a record high, up 56.52 percent from the same period last year.

Experts say this phenomenon can be viewed from two perspectives. Hours of waiting to charge a vehicle indicates the charging infrastructure remains inadequate.

But considering the sudden surge in the number of EVs on the road during the holiday, the inadequacy may not be as severe as imagined, they said.

Statistics from State Grid show that the average daily electricity consumption by electric cars along the expressway network during this year's National Day holiday was four times the figure on the average non-holiday day.

There were 2.1 million charging piles in China by the end of September, up 52.3 percent from the same period last year, according to the China Association of Automobile Manufacturers. That accounted for around one third of electric cars and plug-in hybrids in the country.

However, the growing acceptance of EVs for both daily and long trips, as evidenced by the long queues at charging stations, is alerting charging operators and other players in the industry to the possibility of bigger problems if they don't take the issue seriously.

The CAAM estimates that sales of electric cars and plug-in hybrids will reach 2.4 million units this year, up 76 percent from 2020, from its estimate of 1.8 million units in January.

The China Passenger Vehicle Association is even more optimistic, expecting this year's deliveries to reach 3 million units.

"The upward trend will continue in the coming months as they (EVs) are increasingly accepted by consumers," said Cui Dongshu, the association's secretary-general.

The prospect of such a promising upward trend would require a more efficient way to get them charged.

However, even China's largest charging pillar operator, TGood, is yet to make a profit, although its losses are getting smaller each year. It lost 136 million yuan ($21.11 million) in 2018, 111 million yuan in 2019 and 77.7 million yuan in 2020.

"The losses were primarily because of the vast investment made in charging pillars," said TGood Chairman Yu Dexiang.

But investors are confident in the sector. TGood raised 16.5 billion yuan in the first half of the year, pushing its valuation to around 13.6 billion yuan. It plans to go public within the year.

Companies are exploring other ways to either to make vehicles charge at a faster speed, or to swap their batteries instead of charging them.

GAC Aion has launched a model that can extend its range by over 100 kilometers while recharging in just five minutes.

Swiss engineering company ABB has launched a charger that can charge up to four vehicles at once, and can fully charge any electric car within 15 minutes.

Many carmakers in China, including Nio and BAIC BJEV, are exploring battery swapping technology. Nio is building over 4,000 battery-swapping stations by 2025, with 500 having been available in the country already.

Last August, China approved its first national battery-swapping safety standard for electric vehicles. It said more research needs to be done on battery-swapping, swappable battery packs and battery-swapping interfaces, as well as examining any potential failure points.

"Battery swapping provides an approach to decarbonize heavy transport with quick refueling times, in addition to facilitating China's transition to green cars by 2035," said Mi Siyi, an analyst with BloombergNEF.

"While home and workplace chargers will be most favored by private EV owners, battery swapping, together with fast-charging stations, can gain more popularity among fleet operators, particularly taxis, ride-hailing vehicles and light commercial vehicles," she said.