Sen. Thomas J. McIntyre (D-N.H.) has introduced legislation to create a new federal agency to make loans for solar energy features in new and existing homes.

McIntyre's bill would create a Solar Energy Development Bank, which would make 30-year loans at 3 percent interest. McIntyre acknowledged that House and Senate members of a conference committee working out a federal energy bill have agreed on a solar energy loan program but said he has two reasons for introducing his bill.

First, there is no way of knowing which of the House-Senate energy bill provisions eventually will be enacted into law.

Second, a study by the Congressional Research Service of the Library of Congress suggests to him that the provisions agreed to in the energy bill are inadequate.

"This study shows that the existing loan programs of the federal government and the proposed program in the National Energy Act, probably would not reach the majority of people who may be interested in obtaining solar energy loans," McIntyre said.

McIntyre's bill would authorize the appropriation of up to $5 billion. How much money would eventually be made available would depend on the passage of an appropriation bill and it is customary that less money is actually appropriated for federal programs than is authorized.

Under McIntyre's bill, loans could be as large as$100,000 for solar facilities for a commercial building and up to $7,5000 for a single-family residence. At least 60 percent of all loans would have to be made on homes or apartments.

The Library of Congress study said theprovisions agreed to by the conferees working on the energy bill will have only a "modest effect" on the demand for solar hardware. This was attributed to the fact that families wishing to install solar improvements - possibly a solar hot water heaterM for instance - usually prefer to pay cash rather than use a home improvement loan.

"The federal government at the present time finances only a trivial percentage (less than 3 percent) of all home improvement activity," the Library of Congress study said. "A more substantial portion of newly built homes (24 percent) are financed through FHA, VA and the Farmers Home Administration.

Under McIntyre's bill, loans could be made to individuals directly or through banks, savings and loan associations and other institutions. The institutions would receive fees for processing the loans.