A unit of Tokyo Electric Power Company Holdings Inc. has launched an indoor vertical farm in Shizuoka that can yield up to 5 tons of produce a day — one of the world's largest such facilities to rely solely on artificial lighting.

Tepco Energy Partner Inc. started running the farm Wednesday in Fujieda, Shizuoka Prefecture, to grow lettuce and other leafy greens by using light-emitting diodes.

The company aims to initially produce about a ton of vegetables per day at the 9,000-sq.-meter facility and begin shipping around August. It said it plans to raise the output to 5 tons a day by next year and move into the black in 2023.

Vertical farming via artificial lighting has been drawing attention as a way to ensure stability in food production and distribution because it is not affected by undesirable weather and other risks, such as epidemics, the Tepco unit said.

Such facilities are also expected to provide solutions to problems faced by Japanese agriculture, such as the decline in the number of farmers and the aging of those still working their land, it added.

Tepco Energy Partner, which engages in electricity retailing, also said an indoor environment allows farmers to better maintain quality and freshness, which can help reduce food waste.

"We would like to make the most of our energy-saving technologies," said an official of the company. "Since it's indoors, vegetables are resistant to abnormal weather, and they are also safe because they are grown without using agrichemicals."