Patterson Pass Project

CLIENT: Confidential

LOCATION: California

IEC provided preliminary engineering services for a nominal 400 MW power plant consisting of four GE LMS100 units in simple cycle configuration. Responsibilities included developing cost estimates, providing modeling and operations projections, determining emissions, and providing complete preliminary engineering.

Preliminary engineering

IEC developed a preliminary plant layout to support four LMS100 units. IEC also sized and selected BOP plant equipment based on the site specifics and resources. Major equipment included the GE LMS100 turbine package, exhaust CO/SCR catalysts system, Continuous Emissions Monitoring System, ammonia tank and transferring system, natural gas compressor system, water treatment and zero liquid discharge system, water storage tanks, 230 kV switchyard, cooling towers, air compressors, administrative building, warehouse, and electrical equipment.

Cost Estimating

IEC prepared a detailed engineer’s estimate for an LMS100 peaker plant. The estimate included development, licensing, permitting, emission offsets, engineering, procurement, construction, start-up, and testing. The estimate was accurate down to the skid level. The cost estimate was adjusted for union considerations and escalated for the high cost of materials in today’s marketplace. IEC also prepared a cash flow schedule that corresponded with the overall project schedule to support the project on a cash basis.

Modeling and Operations

IEC developed a plant performance model to determine the base load net heat rate and net capacity at monthly average weather conditions as well as minimum and maximum weather conditions at the site elevation. Our experts also provided a plant heat rate curve to project plant performance from 100% to 12.5% plant capacity.  In addition, our experts provided a plant degradation profile, annual operating characteristics of the plant, and monthly maintenance projections.


IEC provided emission calculations to project emissions such as NOx, SO2, CO, CO2 and PM10 for various operating states. Emission calculations included pollutants for combustion turbine emissions, post-SCR and CO catalyst emissions, stack emissions, stack temperature, stack velocity, ammonia slip, and PM10.

Project Descriptions

IEC provided facility descriptions to detail plant operations, major equipment and systems on site, and mechanical and electrical tie-ins at the site boundary. Our engineers also prepared a list of qualified manufacturers for each major piece of equipment. IEC provided a brief description of the potential for additional generation development or expansion (e.g. simple cycle to combined cycle conversion, LMS100 upgrade to Sprint when available by GE, and installation of additional units based on space availability).

Detailed Implementation Schedule

IEC prepared an overall project schedule that included dates and durations for the following activities and milestones: site procurement; design development; permitting and licensing; construction plan; EPC contractor selection and contract negotiation; major equipment procurement, fabrication, and shipping; detailed engineering; site development and civil works; major equipment erection; bulk material installation; BOP plant construction and installation; utility interconnects; start-up and commissioning; and performance testing and acceptance.

Engineering Drawings

IEC engineers provided the following preliminary design drawings to be used as the basis for the LMS100 facility design and associated performance guarantees: Site Plan for Power Plant and Switchyard; General Arrangement; Plot Plan; Single-Line Diagram; Piping & Instrument Diagrams; and Water Balances.