<ARTICLE> UT <LEGEND> This schedule contains summary financial information extracted from the balance sheet, statement of income and statement of cash flows contained in Form 10-K of Commonwealth Energy System for the fiscal year ended December 31, 1997 and is qualified in its entirety by reference to such financial statements. </LEGEND> <CIK> 0000071304 <NAME> COMMONWEALTH ENERGY SYSTEM <MULTIPLIER> 1,000 <FISCAL-YEAR-END> DEC-31-1997 <PERIOD-END> DEC-31-1997 <PERIOD-TYPE> YEAR <BOOK-VALUE> PER-BOOK <TOTAL-NET-UTILITY-PLANT> 1,049,908 <OTHER-PROPERTY-AND-INVEST> 13,767 <TOTAL-CURRENT-ASSETS> 212,986 <TOTAL-DEFERRED-CHARGES> 208,389 <OTHER-ASSETS> 0 <TOTAL-ASSETS> 1,485,050 <COMMON> 43,063 <CAPITAL-SURPLUS-PAID-IN> 111,912 <RETAINED-EARNINGS> 275,795 <TOTAL-COMMON-STOCKHOLDERS-EQ> 430,770 <PREFERRED-MANDATORY> 12,200 <PREFERRED> 0 <LONG-TERM-DEBT-NET> 364,311 <SHORT-TERM-NOTES> 0 <LONG-TERM-NOTES-PAYABLE> 94,075 <COMMERCIAL-PAPER-OBLIGATIONS> 0 <LONG-TERM-DEBT-CURRENT-PORT> 26,653 <PREFERRED-STOCK-CURRENT> 820 <CAPITAL-LEASE-OBLIGATIONS> 12,272 <LEASES-CURRENT> 1,229 <OTHER-ITEMS-CAPITAL-AND-LIAB> 542,720 <TOT-CAPITALIZATION-AND-LIAB> 1,485,050 <GROSS-OPERATING-REVENUE> 1,041,744 <INCOME-TAX-EXPENSE> 31,040 <OTHER-OPERATING-EXPENSES> 923,054 <TOTAL-OPERATING-EXPENSES> 954,094 <OPERATING-INCOME-LOSS> 87,650 <OTHER-INCOME-NET> 2,601 <INCOME-BEFORE-INTEREST-EXPEN> 90,251 <TOTAL-INTEREST-EXPENSE> 40,350 <NET-INCOME> 49,901 <PREFERRED-STOCK-DIVIDENDS> 988 <EARNINGS-AVAILABLE-FOR-COMM> 48,913 <COMMON-STOCK-DIVIDENDS> 34,068 <TOTAL-INTEREST-ON-BONDS> 33,572 <CASH-FLOW-OPERATIONS> 107,551 <EPS-PRIMARY> 2.27 <EPS-DILUTED> 2.27