Green Blackouts?
Increasing renewable generation threatens reliability.
An increased reliance on renewable energy could threaten reliability of the nation’s electric transmission grids by reducing the rotational mass and rotational inertia of on-line turbine generators, thus, reducing the capability of generators to respond to drops in voltage frequency. In fact, data collected from 1994 to 2009 for the Eastern Interconnection already reveals a drop in the grid’s capability (as measured in megawatts) to stop a very rapid drop in frequency — such as a drop of a tenth of a cycle per second.