Recommissioning Non-Operating Power Projects: The Bottle Rock Geothermal Case Study

Abstract

This paper is intended to highlight the successful recommissioning of the Bottle Rock Geothermal Power Project located in the Geysers area of California. This paper is focused on power block considerations and does not discuss steam field and resource issues. The repair and refurbishment of existing infrastructure presents an “opportunity to market” in half the time and at half the expense of green-field development. Even in cases of significant equipment degradation, out dated technology and with only partial regulatory compliance in place. The Bottle Rock project was brought to market and producing electrical energy sales in eighteen (18) months at a cost of less than $600 per kW contract capacity and less the $250 per kW of the installed capacity. It is likely that the project could have been brought on line for 10% - 15% less had certain upgrades not been performed. However, the project may have then suffered repeated availability issues, required a larger staff and operated at a lower steam utilization efficiency. The major benefits of revitalizing existing projects are installed infrastructure and any previous regulatory work. Additionally, the project is tangible in the eyes of investors, regulators and utilities, possibly gaining greater acceptance when seeking financing, permits or a PPA. The difficulties involved with a existing asset are dealing with the equipment selections, site layout and foot print as is. Often the equipment is not properly sized or configured for the current resource plan, may not be supported for parts and it is likely that something is not fully compliant with regulatory requirements. Replacement of usable equipment due to regulatory requirement can be difficult to swallow but, more difficult is the voluntary abandonment of usable equipment for the long term efficiency and viability of the project.