Results of Large Fusion Power Plant Study L. M. Waganer The Boeing Company and John Sheffield, ORNL and JIEE - UT William Brown, James Hilley, Thomas Shields, Duke Engr & Services Gary Garret, Dennis McCloud, TVA Joan Ogden, Princeton Univ US/Japan Workshop on Fusion Power Plant Studies 16-17 March 2000
Purpose of Study This study is designed to evaluate effects on electrical utility system hardware, operations, and system reliability of incorporating large generation units (≥ 3 GWe). Scope of Study • What are the consequences of deploying large, single-unit power plants? • Would the use of co-generation, e.g., hydrogen, improve the prospects of deployment of large plants?
Impact Of Large Electrical Generating Plants(> 1.5 GWe) If size exceeds maximum plant size on Utility system: • Additional spinning and operational reserves are needed. • Additional siting costs may be incurred to cover increased substation and transmission requirements. • Utility production costs may increase due to production dispatch and operating modes of other generating plants. • Additional purchased power may be required during scheduled and unscheduled downtimes.
Co-generation of Hydrogen and Electricity Can Help Lessen Utility Impact Benefit: Generate hydrogen during the night when demand (and POE) is low and electricity when demand (and POE) is high
Co-Generation Considerations • Fusion power plant economics favors full power operation • Co-generation lessens impact on electrical grid and allow load following • Fusion plant can supply high or low temperature process heat to electrolyzers
Study Baseline Assumptions • ARIES-AT was chosen as power plant to supply electricity and process heat • Hydrogen would be produced with high temperature electrolysis (endothermic and exothermic) or conventional alkaline electrolyzers
Fusion Plant Design Basis • Use ARIES-AT design (evolving from ARIES-RS) • Improve plasma physics modeling of Reversed Shear regime • Use SiC first wall and blanket structural material and LiPb/He heat transfer media to enable exit temperatures of 1000 - 1100°C • Employ IHX and closed cycle helium gas turbine to yield thermal efficiencies of 55% to 60% • Increase power core lifetime, reliability, and maintainability to improve availability from 76% to 85+% • Employ low cost manufacturing techniques • Raise ARIES-AT plant capacity to 2 - 4 GW
Low temperature process heat (150°C) is extracted after Brayton turbine. Less energy is available in recuperator. Hence, increasing hydrogen production decreases system efficiency
As More Thermal Power Is Used In Electrolyzer, Fusion Plant Efficiency Decreases
Feasibility Issues for Hydrogen Production • Competition is pushing the price of hydrogen down • Steam reforming of natural gas ~ $5/GJ • Gasification of hydrocarbon fuels ~ $8/GJ • Comparison to $1/gal gasoline ~ $8/GJ • Electrolyzer Plant Equipmentadds ~ $3/GJ to the price of H2 • The remainder of the cost of hydrogen (COH) is directly proportional to the input COE • As electrical demand grows and capacity is reduced, there will be no cheap off-peak electricity (10 to 30 mills/kWh) • Fusion COE would have to be in the range of 30 mills /kWh to competitively produce hydrogen in today’s market • If price of gasoline is $2/gal, hydrogen production with fusion would be competitive with COE values around 60 mills/kWh
Assessment Options and Trades Dedicated Hydrogen Production 100 H 2 Percent Production • Dedicated Hydrogen Plant • Plant size • 1/2 Electricity(Peak) + 1/2 Hydrogen(Off-Peak) • Plant size • Peak electricity price • Electrolyzer cost • Electrolyzer efficiency • Conventional vs. HTE • Off- Peak and On-Peak • Power split during On-Peak 0 Hydrogen Off-Peak, Electricity On-Peak 100 H Electricity 2 Percent Production Production 0 Hydrogen Off-Peak, Hydrogen + Electricity On-Peak 100 75 H Electricity 2 Percent Production Production 0 24:00 0:00 06:00 12:00 18:00 Time of Day
HTE vs. Conventional Electrolysis Dedicated Hydrogen Production
COH, Dedicated Production 35 30 25 Hi T Electrolyzer ARIES-AT 20 Conv. Electrol. $300/kW ARIES-AT Conv. Electrol. $600/kW ARIES-AT Cost of Hydrogen Production ($/GJ) 15 10 5 0 0 500 1000 1500 2000 2500 3000 3500 4000 4500 Fusion Power Plant Size (MWe)
Cost of H2 from Off-peak Fusion Power ARIES-AT On-Peak Power Cost is 6 cents/kWh, f=0.5 25 20 f=.5, High Temp. Electrolysis 15 f=.5, Conventional Electrolysis, $600/kWH2 Cost of Hydrogen ($/GJ) f=.5, Conventional Electrolysis, $300/kWH2 10 5 0 0 1000 2000 3000 4000 5000 Fusion Power Plant Size (MW) Comparison of Electrolysis Types and Costs(50-50 H2/Electricity, On-Peak Price is 6 mills/kWh)
Comparison of On-Peak Electricity Price(50-50 H2/Electricity, Electrolyzer Cost $300/kWH2) Cost of Electrolytic Hydrogen Production from Off-Peak Fusion Power: Conventional Electrolysis $300/kWH2, ARIES-AT 20 18 16 14 Price of On-Peak Electricity 12 Pon= 5 cents/kWh Pon=6 cents/kWh 10 Pon=7 cents/kWh Pon=8cents/kWh Cost of Hydrogen Production ($/GJ) 8 6 4 2 0 0 500 1000 1500 2000 2500 3000 3500 4000 4500 Fusion Power Plant Size (MWe)
H2 Production Cost for Various Operating Strategies: Dedicated H2 Production; 50% On-peak and 100% Off-peak H2 production; 25% On-Peak and 100% Off-peak H2; Off-peak H2 Production Only ARIES-AT , On-Peak Power Cost 6 cents/kWh, Conv. Electrolyzer $300/kWH2 Variable On-Peak Electricity Production(On-Peak Price 6 mills/kWh, Electrolyzer Cost $300/kWH2) 25 20 Dedicated H2 production 15 50% On Peak H2 Production Cost of Hydrogen Production ($/GJ) 25% On Peak H2 Production 10 Off-peak H2 Production (Conv. Electrolysis=$300/kWH2) 5 0 0 500 1000 1500 2000 2500 3000 3500 4000 4500 Fusion Power Plant Size (MWe)
Cost of Hydrogen Production ($/GJ) 35 Steam reforming (NG=$3/MBTU) 30 Steam Reforming (NG=$6/MBTU) 25 Steam Reforming (NG=$6/MBTU, w/CO 20 seq.) H2 Cost ($./GJ) Fusion Dedicated HTE 15 ARIES-AT Fusion Off-Peak ARIES- AT 10 Biomass Gasification 5 Coal Gasification 0 1 10 100 1000 Hydrogen Plant Capacity (million scf H2/d) COH Comparison with Other Sources
Study Conclusions • Main H2 competitors are Biomass and Fossil (coal or NG) gasification • Must use large fusion plants for economy of scale • Fusion plants must be affordable with high availability • COH is lower if subsidized by peak electricity • Production COE must be lower than peak! It may be possible for hydrogen from off-peak fusion power to compete with other low or zero CO2 options, but stringent cost and performance goals must be met and peak power must be valuable.
Some Comparative Data To Visualize Hydrogen Production and Water Usage Food for thought: This production rate would supply enough hydrogen fuel for 20% of the cars in the LA basin if equipped with fuel cells. (Ref. J. Ogden) (~ 1.3 million cars)