<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 six months ended June 30 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>                   JUN-30-1996
<PERIOD-TYPE>                        6-MOS
<BOOK-VALUE>                      PER-BOOK
<TOTAL-NET-UTILITY-PLANT>        1,025,644
<OTHER-PROPERTY-AND-INVEST>         13,581
<TOTAL-CURRENT-ASSETS>             146,893
<TOTAL-DEFERRED-CHARGES>           151,029
<OTHER-ASSETS>                      14,387
<TOTAL-ASSETS>                   1,351,534
<COMMON>                            43,059
<CAPITAL-SURPLUS-PAID-IN>          111,778
<RETAINED-EARNINGS>                256,238
<TOTAL-COMMON-STOCKHOLDERS-EQ>     411,075
<PREFERRED-MANDATORY>               13,590
<PREFERRED>                              0
<LONG-TERM-DEBT-NET>               361,786
<SHORT-TERM-NOTES>                  59,750
<LONG-TERM-NOTES-PAYABLE>                0
<COMMERCIAL-PAPER-OBLIGATIONS>           0
<LONG-TERM-DEBT-CURRENT-PORT>       31,913
<PREFERRED-STOCK-CURRENT>              820
<CAPITAL-LEASE-OBLIGATIONS>         12,747
<LEASES-CURRENT>                     1,640
<OTHER-ITEMS-CAPITAL-AND-LIAB>     458,213
<TOT-CAPITALIZATION-AND-LIAB>    1,351,534
<GROSS-OPERATING-REVENUE>          521,806
<INCOME-TAX-EXPENSE>                22,901
<OTHER-OPERATING-EXPENSES>         443,641
<TOTAL-OPERATING-EXPENSES>         466,542
<OPERATING-INCOME-LOSS>             55,264
<OTHER-INCOME-NET>                   3,221
<INCOME-BEFORE-INTEREST-EXPEN>      58,485
<TOTAL-INTEREST-EXPENSE>            21,115
<NET-INCOME>                        37,370
<PREFERRED-STOCK-DIVIDENDS>            534
<EARNINGS-AVAILABLE-FOR-COMM>       36,836
<COMMON-STOCK-DIVIDENDS>            16,578
<TOTAL-INTEREST-ON-BONDS>           18,230
<CASH-FLOW-OPERATIONS>              58,999
<EPS-PRIMARY>                         1.71
<EPS-DILUTED>                            0