Toshiba CEO of digital products Masaaki Osumi believes people in Japan have changed their relationship with energy following the earthquake and tsunami that hit the east of the country earlier this year.

"The earthquake has changed people's values," he said at the Internationale Funkausstellung (IFA) consumer electronics show in Berlin as the video wall behind him filled with cataclysmic images of overwhelmed sea defences, trucks adrift in swirling waters and towns reduced to matchwood by the earthquake and subsequent tsunami that hit eastern Japan on March 11.

"The biggest change is in people's relationship to energy," Osumi said in his keynote address.

"We suddenly lost the convenience and security that we had enjoyed for a long time and had taken for granted."

Japan forced to cope with electricity shortages

In the hours and days following the earthquake and tsunami, Japan suddenly found itself facing severe electricity shortages: many of its nuclear power stations had automatically shut down as the earthquake struck, while other power stations, both nuclear and thermal, were damaged.

Rolling blackouts were introduced as a way to ration electricity district by district.

"The blackouts were regarded as inevitable throughout the summer," Osumi said, but in the end the willingness of ordinary consumers to reduce their energy consumption or to move it to off-peak periods exceeded authorities' expectations, and the blackouts were avoided. Technology played a role in that, he said, coordinating electricity supply and demand, and storing excess power for periods of peak demand.

Bottom-up action from enthusiastic people

On the coordination side, social media relayed and amplified an online campaign with a simple message: delay turning on energy-hungry appliances such as rice cookers until after 6pm. As for energy storage, earlier this year Toshiba made a small contribution in the shape of a 19-inch LCD TV with a built-in battery able to power the set for up to three hours' viewing, reducing the load on the power grid at peak hours. A timer ensures that the battery is recharged during off-peak hours.

Of course, both those examples involved people taking action to relay messages and programme timers. Reducing future energy consumption will involve action on a grander scale - but action that Japan is now uniquely well placed to take as a consequence of the damage wrought by the quake.

Osumi said there's enthusiasm across Japan for renewable electricity generation at a local scale, and for energy management systems to match demand at the scale of homes or larger buildings.

Chance to rebuild

"We now have an opportunity for creative reconstruction of our cities," he said.

There's also a need for electronic devices with lower, or smarter, power consumption, with the ability to delay power use or match it to generating capacity.

The country may be three to four years from complete reconstruction, Osumi said - but it could be difficult to keep consumers focused on energy saving when Toshiba and its competitors launch ever bigger and brighter TV sets alongside the sober battery-powered models.

Toshiba's latest is a 55in 3D TV requiring no glasses. The 55ZL2G is a so-called 4K2K model, with a resolution four times that of full HD. It will cost €7,999 (£4,956) in Europe, but there's no word yet on how much power it will consume.

German consumers roaming the show might like to ponder Japan's experience before making any buying decisions. Since the quake, the German government has ordered the closure of the country's nuclear power stations by 2022. The reduction in electricity supply will be less abrupt than that experienced by Japan - but will require action nevertheless.