Upper Peninsula Energy Corp is a holding company whose principal subsidiary Upper Peninsula Power Company (UPPCO) is the primary source of earnings. The company through its subsidiary UPPCO generates, purchases, transmits, distributes and markets electric energy in the Upper Peninsula of Michigan. It supplies electric energy to approximately 48,000 customers in a service area of 4,460 square miles. The company also has two non-utility subsidiaries; Earth Source Heating Company and Upper Peninsula Building Development Company. Earth Source Heating distributes goethermal heating and cooling equipment and Upper Peninsula Building Development owns the corporate headquarters building and leases it to UPPCO under a twenty-year renewable lease.