Tower Technology: Large Scale Storable & Dispatchable Solar

Michael McDowell Rocketdyne Program Manager – Solar Power

Pratt & Whitney Rocketdyne Our Solar Vision

HS SL&S Rocketdyne Concentrating Solar Power (CSP) Opportunity October 10, 2005

Pratt & Whitney Rocketdyne We Combine Rocket Science: 50 Years of Rocketdyne Engines

2 4 15 30 668 Astronauts

Saturn Saturn Space Delta Delta Redstone Navaho Jupiter Thor Atlas I/1B V Shuttle I/II/III IV 85 11 46 380 576 19 13 113 305 3 Active Pratt & Whitney Rocketdyne And,And, EnergyEnergy HeritageHeritage

Fast Flux Nuclear Test Facility r ea l c SRE New Production Nu Clinch River Sodium Advanced Reactor Gen IV - Molten Salt / Breeder Fast Reactor Liquid Metal Systems Reactor r

a Solar 1 Solar 2 Power Towers 10 MW 10 MW 15-100 MW Sol

Solar Dish Engine Dynamic System 25 KW 25 kW Fossil Coal Combustion Gasification Methane Coal Gas & Hydrogen Technologies Pilot Plant Combustion Generation Technologies 1950’s 1960’s 1970’s 1980’s 1990’s 2000’s 2010’s North American Rockwell International Boeing UTC Atomics International Energy Systems Rocketdyne Propulsion & Power PWR

Pratt & Whitney Rocketdyne Solar Power Tower Technology: Large Scale Storable & Dispatchable

Collect: • Sunlight concentrated on tower receiver • Molten salt heated to 1050F Store: • Large scale molten salt thermal storage Dispense: • Plant sizes 15 to 100+ MWe • Long-term cost ~5 ¢/kWh Stand Alone ~3 ¢/kWh Hybrid • Dispatchable or 24 hour solar power Rocketdyne Focus – Solar • Plant capacity factor raised & Molten Salt System from 25% to over 65%

Collect, Store, & Dispense High Quality Energy

Pratt & Whitney Rocketdyne Solar-OnlySolar-Only PlantsPlants –– WWithith 2424 HourHour OperationOperation

••PowerPower gen generatioerationn d deecoucouppledled fro fromm energ energyy cocollectiollectionn • 60 – 65% capacity factor with 16 hrs storage Sunlight • 60 – 65% capacity factor with 16 hrs storage

Thermal Energy In Storage Energy

Output Power

Noon Midnight Noon Midnight

MolMoltenten salt salt enables enables eff efficienticient energy energy st storageorage & & truly truly d dispatchableispatchable green green power power

Pratt & Whitney Rocketdyne The Tower is the only system with dispatchable energy

Trough Tower

Dish CPV

Pratt & Whitney Rocketdyne ThermalThermal StorageStorage IsIs CostCost EffectiveEffective

• Thermal storage for only ~8% of plant cost • Low cost storage media • Conventional structural material

• Very low losses ~1% / day

• Thermal storage reduces electrical generation cost • Smaller equipment size • Higher capacity factor

• Increased electricity value

Not for storing energy that is already electricity - electrical conversion efficiencies not high enough

Pratt & Whitney Rocketdyne ThermalThermal StorageStorage MediaMedia PropertiesProperties

Property Solar Hitec Hitec XL LiNO3 Therminol Salt (Calcium mixture VP-1 Nitrate Dipheanyl Salt) biphenyl oxide Solar Salt provides the Composition % best operating NaNO3 60 7 7 KNO3 40 53 45 temperature range for NaNO2 40 electrical generation & Ca(NO3)2 high heat capacity Freezing Point, C 220 142 120 120 13 Upper Temp, C 600 535 500 550 400 Density @ 300C, 1899 1640 1992 815 kg/m^3 Viscosity @ 3.26 3.16 6.37 0.2 300C, cp Heat Capacity @ 1492 1560 1447 2319 300C, j/kg-K

Salt Cost Per Kilogram Relative [$/kg] Storage Cost per/kWh Hitec 0.93 1.8 Solar Salt 0.49 1.0 Solar Salt enables low cost, Calcuim Nitrate 1.19 2.6 [HitecXL] large scale thermal storage Therminol VP-1 3.96 9.8

Pratt & Whitney Rocketdyne IncreasedIncreased ElectricityElectricity ValueValue fromfrom ThermalThermal StorageStorage

100 MWe 4 Hours of Thermal Storage

21% revenue increase from 8% of plant investment

100 MWe No Storage from Brandon Owens Platts Research & Consulting

Pratt & Whitney Rocketdyne Power Towers Successfully Demonstrated at Solar Two

• Technology demonstration project • 1994-1998 • Barstow California • First molten salt power tower system • Intensively instrumented & monitored • Component problems resolved • Achieved project goals • 24 hour solar electric generation • Exceeded performance target • Shut down at project completion

Pratt & Whitney Rocketdyne ReceiverReceiver PanelsPanels AreAre thethe KeyKey ComponentComponent

Fabrication at Rocketdyne Installation at Barstow CA.

Pratt & Whitney Rocketdyne Solar Power Tower Roadmap to Commercial Deployment

First Commercial Electricity Hybrid power towers Electric Plant with fossil

Re ne wa ble Solar 2 Demo Plant he (1994-1998) at Large Power Towers Power parks Successful technology demonstration in California

Process Heat Hydrogen Desalination Production High Quality Energy Tailored to Meet Customer Needs Pratt & Whitney Rocketdyne TheThe NextNext StepStep 5050 MWeMWe PowerPower TowerTower ProjectProject

Plant Description • 7 hours per day generation • 4 hours thermal storage Options • Generation midpoint ~ sunset • 24 hour operation @ 15 MWe with additional thermal storage

• Land area 275 acres

• Tower height ~100 M

• 4300 - 95 M2

Pratt & Whitney Rocketdyne Solar/FossilSolar/Fossil FuelFuel HybridHybrid PlantsPlants AttractiveAttractive AlternativeAlternative toto Solar-OnlySolar-Only PlantsPlants

Heliostat

Storage Tanks

• Add solar to enhance fossil plant performance • Power Booster - increase power generation • Saver - reduce fuel consumption Power Tower • Lowest cost solar energy Central Receiver • Delivers for power cycle • Evaluate best means of integration • Consider as addition to existing fossil plant

Pratt & Whitney Rocketdyne Power Tower Electricity Can Be Competitive

CA Market Price Referent ¢/kWh from Natural Gas

-$ 9/MMBTU

-$ 7/MMBTU Levelized Energy Cost - $5/MMBTU (¢/kWh)

Solar hybrid power plants

Stand alone solar power plants

Stand alone plant data from Sargent & Lundy Pratt & Whitney Rocketdyne StrategiesStrategies DefinedDefined toto MeetMeet CostCost GoalsGoals

Cost components for market Expect a 2/3 reduction in entry commercial plant Technical improvements electricity cost by 2020 • Increase receiver thermal 43% Field flux & absorptivity • Low cost heliostat 16% eTchnical 18% Receiver System designs 4% Tower + Piping • Increase salt temperature 33% cSale 8% Thermal Storage Increase plant sizes

2% Steam Generator (Scale) 18% oVlume System • Increase efficiency 13% Electric Generating Production System • Reduced per kW capital 2% Master Control costs 67% Total 6% Balance of Plant • Reduced per kW O&M costs 4% Structures & Improvements Utilize volume production • Efficient heliostat factory • Fabrication learning curve

Pratt & Whitney Rocketdyne Launching Points Are Developing for the Global Solar Power Tower Market

Two projects expected on-line by 2010

Spain Increased incentives 15 MWe 24hr/day plant PWR receiver supply role discussed South Africa Utility commitment 100 MWe 16hr/day plant PWR identified receiver supplier

Pratt & Whitney Rocketdyne Our Solar Vision

HS SL&S Rocketdyne Concentrating Solar Power (CSP) Opportunity October 10, 2005

Pratt & Whitney Rocketdyne