Revenue bonds issued by any municipal energy agency under the provisions of this act are hereby made securities in which all public officers and public bodies of the state and its political subdivisions, insurance companies, trust companies, banking associations, investment companies, executors, administrators, trustees and other fiduciaries may properly and legally invest funds, including capital in their control. Such bonds are hereby made securities which properly and legally may be deposited with any officer of the state or of any political subdivision of the state or with any agency of the state for any purpose for which the deposit of bonds or obligations of the state is now or may hereafter be authorized by law.