When they need back-up power supplies, institutions such as hospitals and banks turn to companies such as AJ Power, which designs and makes 1,500 diesel generators a year. Headquartered in Northern Ireland, the company says it services customers in 50 countries and has won contracts as far afield as South America and Tanzania. However, 50% of sales are still generated in Britain. Managing director Ashley Pigott set up the company in 2003 after 28 years in the industry, and has seen sales soar 181% a year from an annualised £485,000 in 2004 to £10.7m in 2007.