Steaming, silky instant ramen noodles slurped down late at night are a standard memory for university students around the globe.

But in the savoury snack's birthplace of Japan, which is bracing for possible power shortages as the steamy summer moves into high gear, the treat is undergoing a makeover - served cold, mixed with ice.

"Our marketing department is constantly food-tasting to find new ways to enjoy our products, and last year during the huge energy crunch, one of the staff ended up mixing ice into the cup noodles," said a spokesman at Nissin Foods Holdings Co, Japan's top maker of instant ramen noodles.

"It especially tastes great with Cup Noodle Light," he added, referring to a soy-flavoured version that contains chicken and beef, but cuts both calories and oil.

The cold version is made by mixing ice - a lot of it - into noodles that have been prepared the usual way. This makes the noodles a bit chewier, while the edge is taken off the soup's usual salty flavour.

The new product has clearly hit a need in Japan, which suffered power shortages last summer and faces another serious energy crunch this year due to the shutdown of most of the nation's nuclear plants after the Fukushima nuclear crisis set off by the March 11, 2011 earthquake and tsunami.

Consumers in most parts of the nation, which relied on nuclear power for 30 percent of its energy, have been called to cut back their power usage, with air conditioners set at higher temperatures than usual or turned off altogether.

Nissin began advertising its iced noodles in May and saw sales of the Cup Noodle Light in particular increase by 2.5 times in May and June from a year earlier.

Nissin is not the only firm to come out with special cool food products to beat the heat.

House Foods Corp is now into its second summer of selling instant curry that doesn't need to be heated, while brewer Kirin earlier this year began offering ice cold draft beer topped with frozen froth.

"There's an unprecedented public consciousness regarding energy conservation following the March 11th disaster," said Kazue Matsui, a food analyst and member of Japan Food Analyst Association.

"Everyone's looking to save energy by eating cold food and cooling down from within."