Local banks and companies were joining the government’s power-saving crusade as freezing weather gripped Korea on Friday, sparking fears of a supply shortage.

Subject to a 10-percent mandatory cut in demand and heating limits, most energy-intensive companies have already written their own measures to curtail electricity consumption including power protection systems and backup generators.

“We’re trying to curb unnecessary consumption as much as possible because electricity makes up a large part of our bills, thus is closely linked with the company’s competitiveness,” an official at a major conglomerate said.

The cold spell is expected to run through the end of next week. The government forecasts peak demand between the second and third weeks of January.

Concerns have intensified in recent weeks as a string of technical glitches led to temporarily shutting down some nuclear reactors and power plants in the country’s south, lowering electricity reserves by 4.6 million kilowatts.

Early this month, an unexpected blackout struck Ulsan, some 410 kilometers southeast of Seoul, forcing hundreds of petrochemical plants including those of SK Energy to halt operations.

Banks have been stepping up safeguards against power outages since massive brownouts in mid-September amid an unusual heat wave.

Although most branches have emergency backup solutions known as uninterruptible power supply, or UPS, the sudden power outages retarded operations at more than 400 branches nationwide and stalled numerous automated teller machines.

Millions of residents and industrial workers suffered inconvenience, slamming the government’s failure to give advance notice.

To prevent an electricity crunch, Woori Bank secured two power generator trucks and set up regional networks to help branches borrow extra units at any time.

Hana Bank replaced around 100 units of old UPS systems with new ones this month. It plans to install an independent petrol-fueled generator and separate backup system at its headquarters in downtown Seoul.

KB Kookmin Bank said it has also reinforced its emergency response scheme and UPS solutions at all its branches.

“The UPS system could last two hours so we needed further measures to cope with a possible long-standing blackout,” a banking industry official said.

“We’re working to have partnership with companies that can help us keep charging and rolling out the system.”

Major manufacturers including Samsung Electronics, Hyundai Motor Group and POSCO also have their own power generators. But they said reducing consumption helps lower their utility bills.

POSCO supplies more than 70 percent of its electricity needs from its own devices, which use gases emitted during the steelmaking operations.

Hyundai Heavy Industries, the world’s top shipbuilder, has been running a “peak electricity system,” which adjusts power levels of equipment in the shipyard or requests staff assistance in the office via text messages when demand climbs to the top.

Other companies including LG Electronics, GS Group and Kumho Asiana are also carrying out company-wide campaigns. They said they are cutting the use of lighting and office gadgets like printers and copy machines, and switching to high-efficient bulbs or light-emitting diodes.

By Shin Hyon-hee (heeshin@heraldcorp.com)