Vice Principal Kim Myong Hwa's headache was a chronic blackout which had plagued his night-shift classes since 1995.

Whenever he watched students putting on candle lights in a dark class room, he felt sorry for them.

The poor supply of the state's electric power is due to the abnormal weather and natural disasters, which had hit various places of the country in the past several years, damaging thermal and water plants.

Pyongyang Special School for Daily Necessity Craftworks gives day and night courses in a three-year curriculum to 600 students who were determined to acquire technical skills.

Mr. Kim, 58, had been teaching at the school for the past 36 years, after graduating from Kim Chaek University of Technology.

Mr. Kim in May, 1995, decided to do something to solve the problem based on the

knowledge he had obtained at the electronics department of the Kim Chaek school. It occurred to him that he might be able to create a metal windmill, capable of generating enough power to a night school.

Since then, he had continued to visit a library for two months to study the structure of a windmill, wind force, an anemogram and others. He learned that winds in Pyongyang blow at an average velocity of two meters per second, and concluded that his windmill should be designed to respond to small wind force.

His next step was an access to raw materials. He went around factories and collected iron and aluminum scraps.

With materials in hand and a blueprint in mind, he spent all his free time of the next 20 months on handcrafting and adjusting the wings, shaft and round fan body. "How to adjust the total weight and balance it was the tough part."

He first tried a windmill with eight wings, which did not work at all, and altered it to a six-wing structure. He tried on wings of various lengths, sharpened its blades at different angles and replaced its shaft one after another. The repeated errors and trials, however, did not bear fruit for a while.

A breakthrough came in the spring of 1997 when he moved the position of the attached magnet dynamo to the rear part of the round fan body from its foundation which supported the entire body.

The new attempt which shortened the distance between the wind force and the dynamo, increased the windmill's energy absorbing power, allowing it to generate 20 w of electricity at a two-meter wind velocity per second.

With further additional improvements, Mr. Kim's hand-made windmill was completed on

July 22, 1997, solving the school's energy problem.

As the rumor spread among surrounding areas that his electric generator is particularly efficient for a small unit, administrative organizations, factories and others asked him to make more generating units for their use, and Mr. Kim had produced 11 more in the last half of the year.

As the effectiveness of his masterpiece was verified in 11 other places, it was recommended to be displayed at an exhibition held in January this year in downtown Pyongyang.

The wind-force generator was highly appreciated at the show by many industrial enterprizes including the major Hwanghae Iron Combine which made a decision to produce 1,000 units of its replica per year.