"We were able to meet our customers' needs, sell some power to help other utilities, and still maintain the required reserve for additional demand"
in
http://www.thefreelibrary.com/VIRGINIA POWER REPORTS NO PROB...

self-sufficient energy supply implemented already, some 30 % of the district’s surface area would remain as a reserve for additional demand that might arise in the future
in
http://guessingrenewableenergy.com/gussing/model-region-guss...