The zoning board of appeals shall have specific power to grant special permits to the state, or any political subdivision thereof, and to public utilities for public service purposes, although the application may be in conflict with the provisions of ordinances or regulations adopted under the authority of sections 14-401 to 14-418, except that such permits shall be granted upon such conditions as the zoning board of appeals may deem necessary, proper, or expedient, to promote the objects of such sections.