The Senate Energy Committee yesterday rejected President Carter's plan to require changes in electric utility rate structures to save energy.

Instead, it votd to limit federal activity to intervention in state regulatory proceedings t recommend energy savings changes.

It was the severest setback Carter's omnibus energy-saving bill has encountered in the Senate, though the legislation may get rougher treatment from the Senate Finance Committee, which begins voting on tax portions of the bill next week.

Sen. Henry M. Jackson (D-Wash.), the energy committee chairman , who had loyally supported other non-tax parts of the bill, summed up committee sentiment by saying:

"I don't want the federal government to take over state functions. We seek the same goals (as the President) but by different means. I think intervention is the right approach. If this doesn't work, we'll look at something else."

A Department of Energy official who attended the committee meeting would not comment on the administration's reaction, but conceded the committee had made a "dramatic" change in the President bill.

As approved by the House, Carter's bill would have ordered state utility commissions to direct specific changes in utilities' rate structures to conserve energy. Electricity no longer could be sold below cost to big users. Cheaper rates would be offered customers using power at off-peak times.

When the committee met yesterday to vote on these provisions. Sen. J. Bennett Johnson (D-La.), subcommittee chairman, said he didn't believe sufficient hearings had been held to enable the committee to "act prudently." He added that he opposed letting the federal government help shape utility rate structures because it would be "liable to drive away their capital."

Sen. James A. McClure, (R-Idaho) said the federal government's record in a rgulatory capacity has not been good enough to give it any more authority in the field.

Sen. Pete V. Domenici (R-NM.) moved to defer any action on the subject until more hearings could he held.

Jackson suggested there was a role for the federal government to play as an intervener in regulatory proceedings and in tying together the nation's power systems to share power. Domenici's proposal to take no action now was defeated, 12 to 6.

Without objection, the committee then adopted a Johnson proposal directing the committee's staff to draft language limiting the federal role to intervening in state cases by making recommendations and without power to initiate appeals from state regulatory body decisions.