While technologies linked to smart grids are efficiency-enhancing and could in principle improve the economic viability of existing centralized systems, smart grids are not simply plug-in additions to existing networks, but require new approaches to electricity network design and operation. A significant number also have legal frameworks for mini-grids, although these are often inadequate or incomplete. In some cases, the private sector is permitted to own and operate minigrids and receive some type of public support in the absence of a legal framework, and only a minority of LDCs specify technical standards for mini-grids.