There is widespread and growing concern in North America
about system response to underfrequency events. The
North American Electric Reliability Corporation (NERC)
has led a frequency response initiative. Its report, issued on
30 October 2012, examines the trends in and causes of the
deteriorating frequency response that has been observed over
the past two decades. It provides the rationale for establishing
the responsibilities for maintaining adequate frequency performance
laid out in a new standard on frequency response
and bias that has recently (29 March 2013) been submitted
as a petition to the Federal Energy Regulatory Commission
(FERC) for approval. In 2010, FERC sponsored work by the
Lawrence Berkeley National Lab (LBNL) that identified
metrics useful in planning and operations of a system with
large amounts of variable generation. One focus is the concern
that the addition of substantial amounts of wind power
may exacerbate the observed decline in frequency response.