Household electricity bills have gone up 72.7 percent in the last five years, almost twice as fast as the cost of living in general and most of it because of fuel cost increases, according to a group of utility regulators.

The National Association of Regulatory Utility Commissioners said in its quarterly survey, however, that power prices actually dropped between 1976 and 1977 in nearly one-quarter of the areas surveyed, including the District of Columbia.

A kilowatt hour of electricity enough to light ten 100-watt bulbs for one hour, cost an average of 2.42 cents in 1972 but rose 72.7 percent to 4.18 cents by November 1977, the survey said. The consumer price index, which measures the overall cost of living, rose 396 percent in that same period.

The largest increase came in the period immediately following the Arab oil embargo in the fall of 1973. Fuel costs, which took five years to rise 20 per cent over a 1967 base level, rose another 30 percent by the end of 1974 and as of Jan. 1 were slightly more than double the 1967 mark.

"The figures don't take the coal strike into account," said Gordon L. Pozza, economics director for the association and one of the authors of the report. He said further fuel cost rises would be reflected in the next survey in about three months.

New York City and Newark, N.J., led the list of jurisdictions with high electricity costs, with a sample bill for 500 kilowatt hours costing double the rate in Washington: $41.18 to $20.89. Seattle, Wash., with hydrelectric power, was lowest at $7.33.

In the District of Columbia, the cost of 1,000 kilowatt hours declined from $36.83 in 1976 to $36.06 last year, a drop of 2.1 percent. Prices rose in Maryland, from $41.57 in 1976 to $46.97 in 1977 (13 percent), for customers of Potomac Electric Power Co. But they rose less dramatically for customers of Baltimore Gas and Electric Co.: $36.12 to $38.71 for the same 1,000 kilowatt hours, a 7.2 percent increase.

Bills from the Potomac Edison Co., which recently drew the fire of angry Western Maryland residents over coal strike-related tariffs, rose 14.3 percent between 1976 and 1977, $34.31 to $39.21.

In Virginia, 1,000 kilowatt hours cost $40.92 from Virginia Electric and Power Co. in 1976 and $42.64 at the end of 1977, a 4.2 percent rise.

The spending decline in the Washington area had earlier been attributed by Pepco officials to individual customer conversation efforts, which they said were the strongest inthe nation over the past four years and caused the company to decrease its construction need estimates three times. Much of the usage drop was traced to reductions by the federal government, Pepco's largest user.

The survey covered towns with 2,500 persons or more in 185 utility service areas, or 70 per cent of the nation's electricity consumers. The organization is financed by state governments, all of whose utility regulating commissions are members.