Central Norway is expected to have a gap of 8TWh in 2010 because of heavy investments in energy-intensive industries. The region has two landing sites for natural gas and a considerable potential for wind power to cover the gap. Small-scale hydropower and upgrading of existing hydropower plants also constitute a regional energy potential. Paradoxically, the most realistic investment prospect seems to be extensive investments in new transmission lines to cover the supply deficit. The aim of this paper is to present a problem of regional supply security and public intervention to illustrate and discuss the challenges of arriving at long-term capacity adequacy in deregulated electricity markets. (C) 2009 Elsevier Ltd. All rights reserved.