This paper measures the environmental impacts and life cycle costs associated with electrifying diesel excavators (8.5, 17.5 and 38t) and summarizes experiences from the pilot testing of these electric excavators in Norway. The demonstration and pilot testing of the studied excavators is due to requirements set by Oslo municipality for all public construction sites to be emission-free by 2025. The results show that electrified operation leads to much lower total GHG emissions than diesel excavators, and that electrified excavators can have lower costs over their life span than their diesel-powered equivalents, even if they have a higher investment cost. Experiences from pilot testing show that electric excavators can provide the required performance and that they can be successfully used on construction sites with only minor adjustments to operational procedures. Although the studied cases and pilot tests are motivated by local Norwegian requirements, they imply a large potential for wider application of the technology for fully electrified construction machinery.