Any other law to the contrary notwithstanding, the disposal of solid waste by a county or project party is a utility service, but shall not place the county or project party in any way under the jurisdiction of the public utilities commission; provided that in the case of a project party, the project party shall not provide any utility services other than the disposal of solid waste or the sales of goods or commodities, including electric energy, produced by the operation of the pollution control project where such sales are made only to registered public utilities, industrial or commercial concerns, or counties or county agencies and not to the general public. If the project party is also a registered public utility, nothing contained in this section shall prohibit the sale of electric energy to the general public.