<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,
1996 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-31-1996
<PERIOD-END>                   DEC-31-1996
<PERIOD-TYPE>                         YEAR
<BOOK-VALUE>                      PER-BOOK
<TOTAL-NET-UTILITY-PLANT>        1,045,627
<OTHER-PROPERTY-AND-INVEST>         13,395
<TOTAL-CURRENT-ASSETS>             196,491
<TOTAL-DEFERRED-CHARGES>           173,442
<OTHER-ASSETS>                           0
<TOTAL-ASSETS>                   1,428,955
<COMMON>                            43,059
<CAPITAL-SURPLUS-PAID-IN>          111,685
<RETAINED-EARNINGS>                260,950
<TOTAL-COMMON-STOCKHOLDERS-EQ>     415,694
<PREFERRED-MANDATORY>               13,020
<PREFERRED>                              0
<LONG-TERM-DEBT-NET>               355,305
<SHORT-TERM-NOTES>                       0
<LONG-TERM-NOTES-PAYABLE>          118,475
<COMMERCIAL-PAPER-OBLIGATIONS>           0
<LONG-TERM-DEBT-CURRENT-PORT>       21,913
<PREFERRED-STOCK-CURRENT>              820
<CAPITAL-LEASE-OBLIGATIONS>         12,346
<LEASES-CURRENT>                     1,531
<OTHER-ITEMS-CAPITAL-AND-LIAB>     489,851
<TOT-CAPITALIZATION-AND-LIAB>    1,428,955
<GROSS-OPERATING-REVENUE>        1,010,905
<INCOME-TAX-EXPENSE>                36,099
<OTHER-OPERATING-EXPENSES>         878,141
<TOTAL-OPERATING-EXPENSES>         914,240
<OPERATING-INCOME-LOSS>             96,665
<OTHER-INCOME-NET>                   4,878
<INCOME-BEFORE-INTEREST-EXPEN>     101,543
<TOTAL-INTEREST-EXPENSE>            42,368
<NET-INCOME>                        59,175
<PREFERRED-STOCK-DIVIDENDS>          1,050
<EARNINGS-AVAILABLE-FOR-COMM>       58,125
<COMMON-STOCK-DIVIDENDS>            33,155
<TOTAL-INTEREST-ON-BONDS>           35,586
<CASH-FLOW-OPERATIONS>              63,325
<EPS-PRIMARY>                         2.70
<EPS-DILUTED>                            0