Aided by at least $43 million in assistance from the government of Massachusetts and an innovative solar energy technology, Evergreen Solar emerged in the last three years as the third-largest maker of solar panels in the United States.
But now the company is closing its main American factory, laying off the 800 workers by the end of March and shifting production to a joint venture with a Chinese company in central China. Evergreen cited the much higher government support available in China.