In carrying out activities under section
1701z–1 of this title, the Secretary may, after consultation with the National Science Foundation, undertake demonstrations to determine the economic and technical feasibility of utilizing solar energy for heating or cooling residential housing (including demonstrations of new housing design or structure involving the use of solar energy). Demonstrations carried out under this section should involve both single family and multifamily housing located in areas having distinguishable climatic characteristics in urban as well as rural environments. To carry out the purpose of this section the Secretary is authorized—