A solar agreement or wind agreement shall run with the land benefited and burdened and shall terminate upon the conditions stated in the solar agreement or wind agreement. The initial term of a solar agreement or wind agreement shall not exceed forty years, except that the parties to a solar agreement or wind agreement may extend or renew the initial term by mutual written agreement. A wind agreement shall terminate if development of a wind energy conversion system has not commenced within ten years after the effective date of the wind agreement, except that this period may be extended by mutual agreement of the parties to the wind agreement.