Taiwan will invest NT$ 5.49 billion yuan (about 178.44 million US dollars) in the next two years, aim to assist local governments on replacing 692,000 units mercury street lights by LED street lights in the end of 2016. After the completion of replacement, Taiwan will become the world’s first region which eliminates mercury lights comprehensively. It is expected to save up to 640 million Kwh annually, will reduce NT$ 1.1 billion yuan (about 35.75 million US dollars) electricity cost and NT$ 346 million yuan (about 11.24 million US dollars) maintenance costs, the local government expenditure can save up to NT$ 7.23 billion yuan (about 235 million US dollars) in five years.