CDAWG November 13, 2013 Ivanpah Solar Project: Helping to meet California’s Climate Change Goals by Shankara Babu, ESH Manager, NRG O&M Doug Davis, Senior Compliance Manager, BSE

Corporate Organization Solar Partners Holdco, LLC - Equity Investors NRG Google BrightSource Three Individual Projects Solar Partners II – Ivanpah #1. Selling power to PG&E. Solar Partners I – Ivanpah #2. Selling power to SCE. Solar Partners VIII – Ivanpah #3. Selling power to PG&E. Southern California Edison Transmission Upgrade Implementing their El Dorado to Ivanpah Transmission Project (EITP)

CSP - Technologies Linear Fresnel Reflectors Parabolic troughs Parabolic dishes Central Receiver / Heliostats

Energy from Sun Insolation is a measure of solar radiation energy received on a given surface area and recorded during a given time. Direct insolation is the solar irradiance measured at a given location on Earth, excluding atmospheric diffused insolation. Absorbed solar radiation is converted to thermal energy, causing an increase in the object's temperature.

Overview

Power Block Configuration SOLAR RECEIVER STEAM GENERATOR (RILEY POWER) Concentrated sunlight converts water in a boiler to high-temperature steam. OPTIMIZATION / CONTROL SOFTWARE (BRIGHTSOURCE) Solar Field Integrated Control System is the proprietary optimization software to manage heliostat positioning and optimize concentrated sunlight on the boiler. AIR-COOLED CONDENSER (SPX) Environmentally friendly in design, using 95% less water than competitive technologies. TURBINE (SIEMENS) Steam powers turbine to produce electricity – then is converted back to water through an air-cooled condenser. HELIOSTATS (BRIGHTSOURCE) Software-controlled field of mirrors concentrate sunlight on a boiler mounted on a central tower.

Overview

Site Geography and Footprint Tower Project, about 3600 acres Edge of U1 SF to edge of U3 SF = 5 miles Unit 1 to Unit 3 Tower = 3.2 miles Tower Height 459” steel structure with the boiler on top Tuned Mass Damper

Solar Steam Generator Boiler Controls 2646 psig / 1054 F Evaporator Super Heater Reheat Controls IR Cameras – 2/wall, total 8 Heat Flux Sensors – 24 pairs of TCs embedded in SH, RH, and EVA tubes. About 1180 loops, 120 MOVs (networked), 17 CVs 100% steam bypass, no sky valves

Solar Steam Generator Layout Superheat Protection Panels Evaporator Reheat

Steam Turbine Generator Siemens SST-900 HP and IP Turbine HP – 7200 RPM IP – 3600 RPM Generator 135 MVA 3600 RPM Design Fast Startup Daily Cycling

Air Cooled Condenser ACC Water Consumption limited to 100 acre-ft / year 3 Streets of 5 fans / Unit 2 Speed

Solar Field 18

System Components Overview: Focal Length Focus length too long Heliostat focused on SRSG Focus length too short

System Components: Heliostat  LH-2.2 Heliostat  Mirrors  Metal support structure  Dual-axis drives  Heliostat controller  Focuses sun on SRSG  Under SFINCS control

Solar Field Control System (SFINCS) Heliostat desired aiming points calculating to: Flux vs Load balancing Implement quick flux reduction / defocusing Measuring SRSG skin temperature Alert on crossing temperature limits

Solar Field Control System (SFINCS) Inputs: Heliostat calibration data, heliostat reflectivity Weather data Skin temperature of panels SFINCS state, operation mode and sensor info DCS SP & control parameters Outputs: HAPA (Heliostat Aiming Point Array): a collection of aiming points (1/heliostat), sent to SF through SFC Is there potential flux for operation? Is tracking active (per SRSG section)? Process information, flux and temperature maps Alarms on flux / temperature deviation

Weather System Insolation Matr East Weather Statio Tower Weather Statio Insolation Weather Statio West Weather Statio

General Description  Weather Station Measurements  Radiation  Wind  Direct Normal Radiation (DNR) - Critical for optimizing performance  Global Horizontal (GH) radiation  Diffused Horizontal (DH) radiation  UV horizontal radiation  Wind  Wind speed in different locations - Critical for SF safety during high winds  Wind direction  Ambient weather  Ambient temperature  Relative humidity  Barometric pressure  Rainfall

Instrumentation

California Renewables Portfolio Standards [RPS] Under California's Renewables Portfolio Standard (RPS) statutes, all sellers of electricity in California, including publicly owned utilities (POUs), investor-owned utilities (IOUs), electricity service providers (ESPs), and community choice aggregators (CCAs), are required to procure a portion of their electricity retail sales from eligible renewable resources to meet the following goals: 20 percent by the end of 2013 25 percent by the end of 2016 33 percent by the end of 2020

Environmental Considerations Flora and fauna – Protected Species Desert Tortoises Succulent Desert Plants Weed Management Water - 100 acre-ft/year 2 – onsite wells provide all the water Air – Emissions Title V GHS/cap and trade Avian and Bat - nesting and migratory birds Surveys Monitoring Reports

Ivanpah Stats 7.8 Million man-hours worked without a lost time accident 2600 employees at the peak of construction 70 O&M employees post construction 2.3 Billion 3 units generating 373 MW Will power 140K homes

Questions?