A worker displays biomass fuel at the Diageo Roseisle distillery in Scotland March 20, 2014. Scotch whisky distillers are burning their unwanted grain byproducts, wood chips and other types of biomass for a source of energy in remote areas of the Highlands, where gas links are scarce and fuel oil is pricey. The production of Scotch whisky has evolved over more than 500 years and is steeped in tradition. It is also a big business, generating 4 billion pounds ($6 billion) a year in exports - a quarter of all Britain's food and drink sales abroad. Picture taken March 20, 2014. REUTERS/Russell Cheyne (BRITAIN - Tags: BUSINESS ENERGY ENVIRONMENT FOOD)