In this paper the capacity adequacy of Crete during Phase I & II of its interconnection with the continental grid is investigated (study period 2021-2050), applying a deterministic and a probabilistic approach. In order to eliminate the capacity deficit, several solutions are evaluated, using both economic and environmental criteria. Preferred solution for Phase I is the case of FSRU rental for the steam units of Atherinolakkos and three new gas turbines (~ 30 MW each), withdrawing Linoperamata steam turbines, in combination with small scale battery energy storage (eg 30-50 MW@ 4h) and an increase of renewables capacity to substitute local higher cost conventional generation. During Phase II, if generation planning is based on the extreme event of bipolar HVDC link loss, a substantial local generation capacity is required, reaching around 600 MW in the long term by 2050. To achieve that capacity, the lowest cost alternative is installing gas turbines, as strategic reserve units in cold standby, possibly complemented by storage.