The Republican takeover in the Senate has sent shock waves of varying strength through the committees that control tax, energy, spending and business policy legislation.

The shifts in Senate power are expected to significantly strengthen the hand of President-elect Ronald Reagan in carrying out his campaign commitments to cut deeper into federal spending deregulate energy and get government "off the back" of private business.

In personal terms, the changes were startling. Sen. James A. McClure (R-Idaho) learned late last night that he would in all likelihood be the next chairman of the Senate Energy Committee. w"It's a big bite to swallow," said McClure. And to Robert S. Boyd, director of the Republican staff of the Senate Budget Committee, the election outcome puts Republican staffers in the legislative driver's seat for the first time in a generation. "It does change the personality of the Senate," he said.

Changes in key comittees include:

Finance: The Senate Finance Committee chairmanship moves from Sen. Russell B. Long (D-La.) to Sen. Bob Dole (R-Kan.), whose conservative views on tax and energy issues do not clash with Long's for the most part.

Senate observers do not expect a dramatic change in the committee's operations, since Long customarily sought a consensus among the Democrats and Republicans on his committee whenever possible.

Energy: The Senate Energy and Natural Resources Committee moves from the tight control of Sen. Henry M. Jackson (D-Wash.) into the hands of McClure (R-Idaho), a foe of government energy controls and one of the strongest supporters of nuclear power in the Congress.

High priorities for McClure include opening more federal lands to development of coal and exploration for gas and oil and in speeding up production of oil and gas in the short run. "We've had paralysis of government rather than decision-making," McClure said in an interview. Even without new legislation, the government can move much faster, he said.

Rep. David Stockman (R-Mich.), with McClure cochairman of Reagan's advisory committee on energy, predicted the Reagan administration and congressional allies would speed up the deregulation of natural gas and crude oil.

Banking: The Senate Banking Comittee, under its new chairman, Sen. Jake Garn (R-Utah), can be expected to lead off the new session of Congress with a hearing on the funding of the Export-Import Bank, according to M. Danny Wall, who will be the Republican majority staff director. "Garn is concerned by our country's inability to complete," says the staff director. This may mean an increase in the lendable funds for the Ex-Im Bank.

Staff members predict that under Garn the committee will take a decidedly pro-banking-industry bent.

The committee also will decide whether to continue funding of the Council on Wage and Price Stability, which has governed President Carter's anti-inflation program. The Republicans have charged that the council is ineffective.

Commerce: In line apparently to head the Senate Commerce Committee is Sen. Robert Packwood (r-Ore.), a widely respected moderate. But the structure and makeup of the panelS powerful subcommittees is very much in doubt. The communications subcommittee may be headed by Sen. Barry Goldwater (R-Ariz), if he retains his lead in his close reelection contest.

Appropriations: There is no more dramatic change in Senate committee leadership following the Republican takeover than the switch on the Senate Appropriations Committee, some Senate staff members said.

Gone is Sen. Warren G. Magnuson (D-Wash.), whose Senate service began under President Franklin D. Roosevelt and who remained a determined supporter of the health, labor and social welfare programs that had their roots in Roosevelt's New Deal.

He will be replaced by Sen. Mark Hatfield (R-Ore.), a moderate, who is expected to give strong support to Republican efforts to cut deeper into the federal budget.

Budget: The Senate Budget Comittee, headed by Edmund S. Muskie until he became secretary of State and since then by Magnuson, will be run by Sen. Pete V. Domenici (R-N.M.), who will give strong support to a Reagan administration campaign to cut federal spending.