The corporate purpose of each corporation formed under this chapter shall be to render service to its members only, and no person shall become or remain a member unless such a person shall use energy supplied by such corporation and shall have complied with the terms and conditions in respect to membership contained in the bylaws of such corporation. The membership fee of the corporation shall not exceed $10.00. Should the corporation acquire any electric facilities already dedicated or devoted to the public use, it may, for the purpose of continuing existing service and avoiding hardship, continue to serve the persons served directly from such facilities at the time of such acquisition without requiring that such persons become members. In no event shall the number of such nonmembers served exceed 49 percent of the total number of persons served by the corporation. Such nonmember customers shall have the right to become members upon nondiscriminatory terms. The rates to such nonmembers shall be on a cost basis and may exceed the rates to members by only such amounts as may be necessary to meet the full actual cost of service to such nonmembers. Any corporation formed under this chapter rendering service in a county in this state adjacent to a county or counties of any other state is authorized, upon compliance with the laws of such other state, to render service in such county or counties of such other state, and persons served in such county or counties may become members.