G59 Embedded Generator Regulations
G59 is the regulation surrounding the connection of any form of generator device to run ‘in parallel’ or ‘synchronised’ with the mains electrical utility grid (National Grid). The regulation has its roots in Ofgem rules, and is administered as the Energy Networks Association Engineering Recommendation G59/2-1 “Recommendations for the connection of generating plant to the Distribution System of Licensed Distribution Network Operators – Amendment 1”.
This is relevant for all power generation, including combined heat and power units as well as generators being used for peak-lopping, or grid parallel use, greater than 16A per phase. For anything below this the Engineering recommendation G83/1-1 applies.