4.3

                            CERTIFICATE OF FORMATION

                                       OF

                               VPC GEOTHERMAL LLC


     This Certificate of Formation of VPC Geothermal LLC (the "LLC"), dated as
of February 19, 1999, is being duly executed and filed by an authorized
person to form a limited liability company under the Delaware Limited Liability
Company Act (6 Del. C. Section 18-101, et seq.).

     FIRST. The name of the limited liability company formed hereby is VPC
Geothermal LLC.

     SECOND. The address of the registered office of the LLC in the State of
Delaware is c/o The Corporation Trust Company, Corporation Trust Center, 1209
Orange Street, Wilmington, Delaware 19801.

     THIRD. The name and address of the registered agent for service of process
on the LLC in the State of Delaware are The Corporation Trust Company,
Corporation Trust Center, 1209 Orange Street, Wilmington, Delaware 19801.

     IN WITNESS WHEREOF, the undersigned has executed this Certificate of
Formation as of the date first above written.


                                  By: /s/ Douglas L. Anderson
                                     ---------------------------
                                  Name:  Douglas L. Anderson
                                  Title:  Assistant Secretary