Carla A. Hills, who was Secretary of Housing and Urban Development (HUD) under former President Gerald R. Ford, arrived at Harvard yesterday for a two-day stay as a visiting fellow of the Institute of Politics.

At an informal gathering with business school women at Morris Hall yesterday, Hills discussed her current job as volunteer co-chairman of the Alliance to Save Energy.

The fact that Americans use far more energy than other nations and waste half of it "just doesn't create a happy international perspective," she said.

"The past three presidents have tried to mobilize public opinion on the energy crisis and were unable to do so. You wonder how many calling cards it takes to get the attention of the American people," she said.

Hills said she hopes the alliance would be "a new voice" on energy matters, and one more credible than the government, oil companies, or advertising agencies.

Hills defended the role of special interest groups in government, saying, "Our government is a gathering of special interests, and if people with special interests don't speak up, who will?"

At a meeting of about 100 people at Kirkland House last night Hills reiterated her earlier statements about the energy situation in the United States and discussed the role of HUD.

A major policy change has occurred at HUD since 1974, Hills said. Since that year the government has been subsidizing rents instead of providing bricks and mortar for housing projects, she said.

The advantage of the new policy is it "puts poor people on the demand curve" for housing, where they can find the best available housing with the money they receive, she added.