. rental expense was $ 54 million , $ 58 million and $ 54 million in 2002 , 2001 and 2000 , respectively . future minimum lease commitments are as follows ( in millions ) : in connection with the lease of the two power plants , the subsidiary is required to maintain a rent reserve account equal to the maximum semi-annual payment with respect to the sum of the basic rent ( other then deferrable basic rent ) and fixed charges expected to become due in the immediately succeeding three-year period