Base-Load Nuclear Power
To Meet the Need for Variable
Energy Output: The Value of Heat
Charles Forsberg
1Department
of Nuclear Science and Engineering; Massachusetts Institute of Technology
77 Massachusetts Ave; Bld. 42-207a; Cambridge, MA 02139; Tel: (617) 324-4010;
Email: [email protected]; http://web.mit.edu/nse/people/research/forsberg.html
Low-Carbon Energy Economy Workshop
Massachusetts Institute of Technology
Cambridge, Massachusetts
26-27 May 2015
The Challenge
2
For a Half-Million Years Man Has Met
Variable Energy Demands by
Putting More Carbon on the Fire
Wood Cooking Fire
Natural-Gas Turbine
How Do We Replace Variable Carbon-Based
Energy Production in a Low-Carbon World?
3
Must Address Total Energy Needs
Industry, Transportation, Commercial and Residential
Estimated U.S. Energy Use in 2013: ~97.4 Quads (LLNL)
4
HOURS/YEAR at Price
Low Carbon Futures Imply More
Low and High Priced Electricity
Large Solar or
Wind Output
Collapses
Electricity Prices
Distribution of electricity prices, by duration,
at Houston, Texas hub of ERCOT, 2012
No Sun and No Wind
High Electricity Prices
Current
Prices
←Future Market?
PRICE: $/MWh
Need to Transfer Excess Low-Price Energy
From Electric Sector to Other Sectors of Economy
5
Price Collapse Challenge for High-CapitalCost Low-Operating Cost Systems
Limits Use of Non-Fossil Power Generating Systems*
Nuclear Operating at
Expensive Part Load
Wind and Solar With
Expensive Energy Storage
Revenue Collapse becomes significant at 10 to 15% Solar,
20 to 30% Wind, and ~70% Nuclear Deployment
*Electricity from many fossil fuel systems primarily fuel
costs. Can afford to operate at low-load factors
6
Low-Carbon World Economics
Energy is ~10% GNP, can not
afford to double that cost
Nuclear, wind, and solar are
capital intensive; must maximize
production to minimize cost
7
Addressing the Challenge
Using Heat from Nuclear
Reactors
8
Nuclear Energy is the Low-Carbon
Large-Scale Heat-Producing Technology
Heat to Storage, Brayton Power Cycles, and Hybrid Systems
9
I. Heat Storage for
Peak Power and Industry
Nuclear Heat to
Heat Storage
↑ Low-Temperature Heat Store (<300°C)
↓High-Temperature (to 1800°C) Heat Store
Grid Electricity to
Heat Storage
10
Base Load Nuclear Power Plant
Electricity
Heat
Heat Storage
Heat to Electricity
Industrial Heat
Demand
Electricity
Heat
Variable Electricity
11
Many Heat Storage Technologies Couple
Directly to Existing Light-Water Reactors
Technology
Description
Storage
Time (Hr)
Size
(GWh)
Liquid Heat
Capacity*
Store molten nitrate or
other material at low
pressure
10
<10
Steam
Accumulator*
Store high-pressure
water-steam mix
10
<10
Geothermal Hot
Water
Store hot water 1000 m
underground at pressure
Geothermal Rock Heat rock to create
artificial geothermal
deposit
Fast Response
100
100 to
1,000
1000+
1,000 to
10,000
*Heat Storage Options Used Today in Solar Thermal Power Systems
Heat Storage Is Much Cheaper
Than Electricity Storage
DOE Cost Goals for Stored Energy Systems
Thermal: $15/kWh
Electrical: $150/kWh
Liquid Nitrate Salt
Large-Scale Thermal Storage Couples to Nuclear Heat Sources
13
Electricity-to-Heat Storage and Use
High-Temperature Heat Storage
Firebrick Resistance-Heated
Energy Storage (FIRES)
Firebrick electrically heated
up to 1800 C when electricity
prices less than fossil fuels
Use hot firebrick as heat
source

Figure courtesy of General Electric Adele
Adiabatic Compressed Air Storage Project
that is Integrating Firebrick Heat Storage
with Gas Turbine

Industrial heat
Heat to reactor for peak
electricity production
14
FIRES Stores Heat in Electrically-Heated
Firebrick to Provide Hot Air to Industry
Use LowPrice
Electricity
to Heat
Firebrick
Cold
Air
Heated
Firebrick
Hot Air
Adjust
Temperature:
Add Cold Air
or Natural
Gas
Industrial
Kiln or
Furnace
Using Hot
Air
15
Energy Storage Capability: 1 m3 Firebrick
(~0.5 MWh/m3) Vs. Tesla S Electric Batteries
=
Tesla Stand-Alone House
Battery: $350/kWh
plus Converter, Installation, Etc
Firebrick ~$1/kWh
Expect <$5/kWh total
1 GWhr = Firebrick Cube 12.6 m on a Side
16
FIRES Stops Electricity Price Collapse that
Limits Wind and Solar Deployment
HOURS/YEAR at Price
Transfers Low-Price Electricity to Industrial Sector as Heat;
Reduces Greenhouse Gas Releases, Improves Nuclear Economics
Natural Gas
Defines
Minimum
Price Of
Electricity
Distribution of electricity prices, by duration,
at Houston, Texas hub of ERCOT, 2012
High Price Electricity
When No Sun / Wind
Current
Prices
←Future Market?
PRICE: $/MWh
No Electricity Less Than Price of Natural Gas
17
II. Nuclear Air Brayton
Combined Cycles (NACC)
Fluoride-salt-cooled High-temperature Reactor (FHR)
Sodium Fast Reactor (SFR)
High-Temperature Gas-Cooled Reactor (HTGR)
18
Advancing Natural Gas Combined Cycle
Technology Enables Coupling to
High-Temperature Nuclear Reactors
Next-Generation Reactors May Couple to
Nuclear Air-Brayton Combined Cycles (NACC)
19
FHR: Salt Cooled Reactor Coupled to
Nuclear Air-Brayton Combined Cycle (NACC)
Modified General Electric F7B Combined Cycle Gas Turbine
20
NACC for Variable Electricity Output
Filtered
Air In
Heat from FHR
Peak Air
Temperature:
670°C
Add Natural
Gas, H2 or
Stored Heat
Stack
Raise Peak Air
Temperature to
1065°C
Nuclear Air-Brayton Combined Cycle Plant
Base-load
Electricity
100 MWe;
42% Efficient
Peak
Electricity
Added 142 MWe;
66% Efficient
Most Efficient Peak Heat-to-Electricity Technology
21
NACC With FIRES Enables Base-Load Nuclear
with Variable Electricity and Steam to Industry
Base-Load High-Temperature Reactor
Heat Storage
FIRES
Base-Load
Heat
Variable Heat
AIR
Inlet
NACC
Stack
AIR
Gas Turbine
Hydrogen
Low Pressure
Hot Air
Heat Recovery
Steam Generator
Variable
Steam to
Consumers
Low-Price
Electricity
Electricity
Electricity
22
III. Hybrid Energy Systems
Using Excess Low-Price Energy when Available from
Nuclear, Solar, and Wind to Produce a Second Product
Enabled by Heat Storage, FIRES, and NACC Delivering
Steam and Hot Air for Industrial Processes
Potentially Lowest Cost Option by Reducing
Storage Requirements
23
Nuclear-Renewable Hybrid
Electricity-Hydrogen System
H2 for Fuels, Fertilizer, Metals, and Peak Electricity
Base-Load
Nuclear
Power
Plant
Electricity
and / or
Steam
Output
Two
Products!
Maximum Output
Wind or Solar
Medium-Voltage
Electricity
Steam/
Heat
High-CapitalCost Systems
Operate at HighCapacity Factors
High-Voltage
Electricity
Electricity
Efficient High Temperature
Electrolysis (Electricity +
Heat → Hydrogen)
Hydrogen
Underground
Hydrogen
Storage
A
Hydrogen
Pipeline
Export of
Hydrogen to
Industrial
Users
Hydrogen Production Could Be a Quarter of Global Energy Demand24
24
Conclusion: The Challenge Is Providing
Economic Variable Energy On Demand
Heat Is Central to that Challenge
Nuclear Heat: Low-Cost Heat Storage, Brayton
Power Cycles and Hybrid Energy Systems 25
Backup Information
26R
Biography: Charles Forsberg
Dr. Charles Forsberg is the Director and principle investigator of the HighTemperature Salt-Cooled Reactor Project and University Lead for the Idaho
National Laboratory Institute for Nuclear Energy and Science (INEST)
Nuclear Hybrid Energy Systems program. He is one of several co-principle
investigators for the Concentrated Solar Power on Demand (CSPonD)
project. He earlier was the Executive Director of the MIT Nuclear Fuel Cycle
Study. Before joining MIT, he was a Corporate Fellow at Oak Ridge National
Laboratory. He is a Fellow of the American Nuclear Society, a Fellow of the
American Association for the Advancement of Science, and recipient of the
2005 Robert E. Wilson Award from the American Institute of Chemical
Engineers for outstanding chemical engineering contributions to nuclear
energy, including his work in hydrogen production and nuclear-renewable
energy futures. He received the American Nuclear Society special award
for innovative nuclear reactor design on salt-cooled reactors and the 2014
Seaborg Award. Dr. Forsberg earned his bachelor's degree in chemical
engineering from the University of Minnesota and his doctorate in Nuclear
Engineering from MIT. He has been awarded 11 patents and has published
over 200 papers.
http://web.mit.edu/nse/people/research/forsberg.html
27
28
Nuclear Heat Storage Systems Have
Economic Advantages Versus Heat Storage
Coupled to Solar Power Systems
No geographical limits (Not just high-solar low-landcost desert areas)
More storage cycles per year to cover capital costs


Can charge storage system most of the year
Not limited to sunny days
Economics of scale
Seasonal heat storage—the big challenge
In a Low-Carbon Grid, Nuclear Plants Can Provide
The Economic Energy Storage Capacity
28
Hybrid System Structure
Energy Production (Heat and Electricity), Storage, Use
Gerfriedc / CC-BY-2.5
Second
Product
http://commons.wikimedia.org/wiki
/File:Svartlut_76.jpg
Electricity
29
30
Relative Long-term Roles of Nuclear,
Wind and Solar in Zero-Carbon World
Wind and solar resources/cost vary widely with location


Expect large differences in energy fraction provided based on
local costs across the United States and the world
Wind on Great Plains, Solar in Southwest
Nuclear energy costs independent of location


Nuclear fraction between 25 and 75% of total energy
production (author perspective)
Dispatchable heat source partly drives use
Wildcard: What is the heat demand to make liquid fuels?
Economics ultimately drives system decisions because
energy is such a large fraction of gross national product
and its direct impact on standard of living
30
EIA Cost Estimates for 2018 ($/MWh)
From: Levelized Cost of New Generation Resources in the Annual Energy Outlook 2013: January 2013
Plant type
(Capacity factor)
Levelized Capital
(Includes Transmission
Upgrade)
Fixed/Variable
O&M
Total
Dispatchable
Coal (85%)
66.9
Coal with CCS (85%)
89.6
NG Combined Cycle (87%)
17.0
NG Turbine (30%)
47.6
Nuclear (90%)
High
Operating
Cost Fossil
4.1/29.2
100.1
8.8/37.2
135.5
1.7/48.4
67.1
2.7/80.0
130.3
84.5
11.6/12.3
108.4
73.5
13.1/0.0
86.6
199.1
22.4/0.0
221.5
Solar PV (25%)
134.4
9.9/0.0
144.3
Solar thermal (20%)
220.1
41.4/0.0
261.5
Non Dispatchable
Wind (34%)
Wind offshore (37%)
High Capital
Cost
Non-Fossil
All Except Natural Gas Turbine Assumed to Operate at
Maximum Capacity: Very Expensive Part Load
31
Conceptual Zero-Carbon Nuclear
Renewables Total Energy Cost Structure
Includes Electricity, Industry, Commercial, Transportation, and Residential
Geographical Income
Inequality Caused by
Energy Costs
Biofuels Heat Demand
Concentrated Industrial
Heat Demand
Cost Drivers if AllNuclear Futures Versus
Mixed Energy Sources
Total Costs→
Cost Drivers if AllRenewables Futures
Versus Mixed Energy
Sources
Cheap renewables not
utilized (Existing Hydro,
Great Wind, Etc.)
Biomass contribution to
liquid fuels
High Latitudes
Extreme Weather Events
Driving Storage Needs
Increased Nuclear Fraction →
Technology, Lifestyle, Total Population, and Population
Distribution on Planet Determine Specific Shape
32