PART 1: The real state-of-play and its hidden costs
Denmark generates the equivalent of about 19% of its electricity demand with wind turbines, but wind power contributes far less than 19% of the Nation’s electricity demand.
The claim that Denmark derives about 20% of its electricity from wind overstates matters. Being highly intermittent, wind power has recently (2006) met as little as 5% of Denmark’s annual electricity consumption with an average over the last five years of 9.7%.
In the absence of large-scale electricity storage, any modern electricity system must continuously balance electricity supply and demand, because even small variations in system voltage and frequency can cause damage to modern electronic equipment and other electrical equipment.
Wind power is stochastic,especially in the very short term (e.g., over any given hour, 30 minute, or 15 minute period). This has created a completely new challenge that transmission system operators (TSOs) all over the World are only now learning how to handle. Some draw from Denmark’s experience. But Denmark’s special circumstances make its experience of limited transferability elsewhere.