<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-Q of Commonwealth Energy System for the three months ended March 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>                   MAR-31-1997
<PERIOD-TYPE>                        3-MOS
<BOOK-VALUE>                      PER-BOOK
<TOTAL-NET-UTILITY-PLANT>        1,025,342
<OTHER-PROPERTY-AND-INVEST>         13,469
<TOTAL-CURRENT-ASSETS>             187,451
<TOTAL-DEFERRED-CHARGES>           174,092
<OTHER-ASSETS>                      13,866
<TOTAL-ASSETS>                   1,414,220
<COMMON>                            43,064
<CAPITAL-SURPLUS-PAID-IN>          111,746
<RETAINED-EARNINGS>                278,593
<TOTAL-COMMON-STOCKHOLDERS-EQ>     433,403
<PREFERRED-MANDATORY>               12,960
<PREFERRED>                              0
<LONG-TERM-DEBT-NET>               354,262
<SHORT-TERM-NOTES>                  88,100
<LONG-TERM-NOTES-PAYABLE>                0
<COMMERCIAL-PAPER-OBLIGATIONS>           0
<LONG-TERM-DEBT-CURRENT-PORT>       22,965
<PREFERRED-STOCK-CURRENT>              820
<CAPITAL-LEASE-OBLIGATIONS>         12,406
<LEASES-CURRENT>                     1,460
<OTHER-ITEMS-CAPITAL-AND-LIAB>     487,844
<TOT-CAPITALIZATION-AND-LIAB>    1,414,220
<GROSS-OPERATING-REVENUE>          316,190
<INCOME-TAX-EXPENSE>                16,674
<OTHER-OPERATING-EXPENSES>         263,624
<TOTAL-OPERATING-EXPENSES>         280,298
<OPERATING-INCOME-LOSS>             35,892
<OTHER-INCOME-NET>                     649
<INCOME-BEFORE-INTEREST-EXPEN>      36,541
<TOTAL-INTEREST-EXPENSE>            10,141
<NET-INCOME>                        26,400
<PREFERRED-STOCK-DIVIDENDS>            252
<EARNINGS-AVAILABLE-FOR-COMM>       26,148
<COMMON-STOCK-DIVIDENDS>             8,505
<TOTAL-INTEREST-ON-BONDS>            8,404
<CASH-FLOW-OPERATIONS>              55,366
<EPS-PRIMARY>                         1.21
<EPS-DILUTED>                            0