Microsoft Begins Using Eco-Diesel in Data Center Generators A backup generator at a Microsoft cloud data center. (Image: Microsoft) Microsoft will use low-carbon renewable fuel to provide emergency power for its cloud region in Sweden, the company said today. The backup generators at a new Microsoft data center in Sweden will run on Evolution Diesel Plus, a fuel that incorporates tall oil, a renewable byproduct of forestry and paper production. The “Eco-labelled” diesel is made by Swedish energy company Preem, which has worked with Caterpillar to ensure it will work in the generators at the Microsoft Azure cloud data center, which is scheduled to begin operating later this year.