"They are challenging us on a daily basis as to where can we introduce renewable storage, solar, even renewable fuels," he told BBC Radio's Good Morning Scotland programme. "This year in the UK we have burned more hydrotreated vegetable oil than at any other time." Aggreko is already working on a £159m contract to supply temporary power for the Tokyo 2020 Olympic and Paralympic Games. Speaking from Aggreko's Dumbarton base, Mr Wells said: "We had some solar hybrid units at a number of jobs this year the Open championship and Glastonbury. "Our new equipment - even if it's using traditional fossil fuels, has to be at the forefront of emissions legislation. "We're driving the engine manufacturers to give us cleaner engines as early as possible."