Distributed resources standards: The case of Spain

Existing distribution networks have not been designed to accept extensive distributed generation (DG). The actual paradigm may change in the near future impelled by a worldwide increasing of DG penetration in distribution grids. This paper presents the status and content of DG Spanish legislation. Fundamental considerations are first discussed, exclusively regarding the grid-interconnection requirement. This paper also analyses the relationship between that guidelines and recognized international standard in a systematic way. Major requirements areas include general specifications, safety and protection strategies, and power quality requirements. Interconnecting DER with the electric power system is traditionally a complicated process that can be facilitated by improving international harmonization.