Task: Question Generation
Input (English): GE (General Electric) Energy's renewable energy business has expanded greatly, to keep up with growing U.S. and global demand for clean energy. Since entering the renewable energy industry in 2002, GE has invested more than $850 million in renewable energy commercialization. In August 2008 it acquired Kelman Ltd, a Northern Ireland company specializing in advanced monitoring and diagnostics technologies for transformers used in renewable energy generation, and announced an expansion of its business in Northern Ireland in May 2010. In 2009, GE's renewable energy initiatives, which include solar power, wind power and GE Jenbacher gas engines using renewable and non-renewable methane-based gases, employ more than 4,900 people globally and have created more than 10,000 supporting jobs.
Output (English): When did GE announce an expansion of its business in Northern Ireland?