P2 is an uninformative name that covers a keystone of the electricity distribution system in Great Britain.  It refers to the engineering standards that govern how connections can be made to the electricity distribution networks – a persistent barrier to simplifying and reducing the cost of distributed generation. That is because it dates back long before networks were considered as anything but passive transport for power from central generating stations. Even the most recent update dates back to 2006, and that is largely unchanged from 1978.