The 8th FC International Meeting 2020
2020.2.25

マスタ タイトルの書式設定

Toward Economically Rational
Hydrogen Production from Solar Energy:
From Battery versus Hydrogen to Battery × Hydrogen

Michihisa KOYAMA
2019-Present COO & Co-founder, X-Scientia Co. Ltd.
2018-Present Professor, Shinshu University
2016-Present Unit Director (Visiting Researcher)
National Institute for Materials Science
2016-Present Visiting Professor, Hiroshima University
2008-2018
Professor, Kyushu University
2003-2008
Assistant Professor, Tohoku University
2002-2003
Postdoctoral Fellow, The University of Tokyo
2002
Ph.D.(Eng.), The University of Tokyo

Landscape, Regime & Niche Techs

2

Landscapedevelopments

SocioTechnicalregime☆Market,User preferences☆Science☆Policy☆Culture☆Technology

TechnologicalnichesGeels, 2005
National Institute for Materials ScienceESG Investment

3

https://theinvestoragenda.org/wp-content/uploads/2019/12/191201-GISGCC-FINAL-for-COP25.pdf

Global Investor Statement to Governments on Climate Change

National Institute for Materials ScienceSustainable Finance4

EU Taxonomy : Classification Frame
Six environmental objectives(1) climate change mitigation(2) climate change adaptation(3) sustainable use and protection of water & marine resources(4) transition to a circular economy, waste prevention
and recycling(5) pollution prevention and control(6) protection of healthy ecosystems
Technical Screening Criteria-Substantial contribution to at least one environmental objective-Doing no significant harm to the other environmental objectives(DNSH)【Nuclear power plant】
excluded from DNSH point of views【Gas thermal power plant】
without CCS: excluded
with CCS: emissions from total supply chain should bemeasured (not estimated)【Coal power plant with CCS】
excluded【CCS】
CCS itself is included

National Institute for Materials ScienceLandscape – Changing Cost in Japan

5

Cost of PV Electricity is expensive in Japan !?

Levelized cost of electricity
associated with fuel (JPY/kWh)

16

LNG

© Michihisa Koyama

2014
12

2030

2030
8

Crossover of Electricity Cost
Expected between 2020-2025

2013

2010

Coal

2014

2013’

2010

Nuclear

2010

2013
4

2013
2003
1998

Photovoltaic

2040 2030 2025

0
0

4

2014’

2014
2030

8

2020
12

16

2017

2014
20

24

2013
28

32

36

40

Levelized cost of electricity associated with plant (JPY/kWh)
M. Koyama, Chapter 16. Toward Economically Rational Hydrogen Production from Solar Energy: From Battery versus Hydrogen toBattery × Hydrogen, in Nanostructured Materials for Next-Generation Energy Storage and Conversion: Photovoltaic and Solar Energy,
T. A. Atesin, S. Bashir, J. Liu Eds., Springer, 2019, pp. 457-470.

National Institute for Materials ScienceNecessity of Energy Storage
Measures
From TEPCO Web Page
Ukishima Megasolar

Output (kW)(Mar 25)

Demand/Output

Low operation ratio：～12%

6

PV Output

Other Technologies

RE4.0

Demand
RE3.0
RE2.0
2

4

6

8

10

12

14

16

18

20

22

24

RE: Renewable
EnergyTime(Mar 17)Time

Cf. Wind：～22%
Small Hydro：～70%
Geothermal：～80%

Demand＜ Supply
Frequency↑
Demand ＞ Supply
Frequency↓
Electricity Business Act
Article 44, Clause 2
Commitment for Frequency Maintenance±0.2Hz （±0.3Hz in Hokkaido）
Output fluctuation of PV・・・⇒Adjusted by Thermal/Pumped hydro plants etc.

National Institute for Materials ScienceLandscapedevelopments

Levelized cost of electricity
associated with fuel (JPY/kWh)Landscape, Regime & Niche Techs
16

12

LNG

SocioTechnicalregime

2013
2030

8

2010

Coal

2014

2013’

2010

2013

4

Nuclear

2010

2013
2003
1998

4

2014’

2014
2030

Photovoltaic

2040 2030 2025

00☆Market,User preferences☆Science☆Policy☆Culture© Michihisa Koyama

2020-2025
太陽光の発電コストが火力・原子力より安価となる

2014
2030

7

8

2020
12

16

2017

2014
20

24

2013
28

32

36

40

Levelized cost of electricity associated with plant (JPY/kWh)☆Technology

TechnologicalnichesGeels, 2005
National Institute for Materials SciencePower Grid with Renewable ?

8

Supply-Demand Gap with Massive Renewable Contribution

Power Demand / GW

200

RE 2.0

150

100

50

Increase in PV share

0

-50
0

2

4

6

8

10

12

14

16

18

20

22

24

Hour

National Institute for Materials SciencePower Grid with RE100 ?

9Izui & Koyama,
IEEJ Trans Electr
Electron Eng,
12 (2017) 453.

National Institute for Materials SciencePower Grid with RE100% ?

10

Supply-Demand Gap with Massive Renewable Contribution
Electricity Demand / GW

200

RE 2.0

150

100

50

Increase in PV share

0

-50
0

2

4

6

8

10

12

hour

14

16

18

20

22

24

RE 3.0National Institute for Materials ScienceH2 Production from PV

11𝐶𝑎𝑝𝑖𝑡𝑎𝑙 𝐶𝑜𝑠𝑡 + 𝑂𝑝𝑒𝑟𝑎𝑡𝑖𝑜𝑛 𝐶𝑜𝑠𝑡 + 𝑀𝑎𝑖𝑛𝑡𝑒𝑛𝑎𝑛𝑐𝑒 𝐶𝑜𝑠𝑡
𝐿𝑒𝑣𝑒𝑙𝑖𝑧𝑒𝑑 𝐶𝑜𝑠𝑡 𝑜𝑓 𝐻𝑦𝑑𝑟𝑜𝑔𝑒𝑛 =𝐴𝑚𝑜𝑛𝑡 𝑜𝑓 𝐻𝑦𝑑𝑟𝑜𝑔𝑒𝑛 𝑃𝑟𝑜𝑑𝑢𝑐𝑒𝑑(LCOH)

Capital Cost ≒ Capacity×Unit Cost/Depreciation Period
Operation Cost ≒ （Electricity & Water Unit Cost）×Capacity×Operation Time
Maintenance Cost ≒ Capacity×Unit Cost×Maintenance Ratio
Amount of Hydrogen ≒ Capacity×Operation Time×Efficiency

𝐿𝐶𝑂𝐻 =

𝑈𝑛𝑖𝑡 𝐶𝑜𝑠𝑡/(𝐷𝑒𝑝𝑟𝑒𝑐𝑖𝑎𝑡𝑖𝑜𝑛 𝑃𝑒𝑟𝑖𝑜𝑑)
𝑈𝑛𝑖𝑡 𝐶𝑜𝑠𝑡 × 𝑀𝑎𝑖𝑛𝑡𝑒𝑛𝑎𝑛𝑐𝑒 𝑅𝑎𝑡𝑖𝑜−+ 𝑒 & 𝐻2𝑂 𝐶𝑜𝑠𝑡 +𝑂𝑝𝑒𝑟𝑎𝑡𝑖𝑜𝑛 𝑇𝑖𝑚𝑒 × 𝐸𝑓𝑓𝑖𝑐𝑖𝑒𝑛𝑐𝑦
𝑂𝑝𝑒𝑟𝑎𝑡𝑖𝑜𝑛 𝑇𝑖𝑚𝑒 × 𝐸𝑓𝑓𝑖𝑐𝑖𝑒𝑛𝑐𝑦

Assuming 5kWh/Nm3-H2
20 JPY/kWh ⇒ 100 JPY/Nm3-H2
13 JPY/kWh ⇒ 65 JPY/Nm3-H2
7 JPY/kWh ⇒ 35 JPY/Nm3-H2
3 JPY/kWh ⇒ 15 JPY/Nm3-H2

National Institute for Materials ScienceH2 Production from PV

12𝐶𝑎𝑝𝑖𝑡𝑎𝑙 𝐶𝑜𝑠𝑡 + 𝑂𝑝𝑒𝑟𝑎𝑡𝑖𝑜𝑛 𝐶𝑜𝑠𝑡 + 𝑀𝑎𝑖𝑛𝑡𝑒𝑛𝑎𝑛𝑐𝑒 𝐶𝑜𝑠𝑡
𝐿𝑒𝑣𝑒𝑙𝑖𝑧𝑒𝑑 𝐶𝑜𝑠𝑡 𝑜𝑓 𝐻𝑦𝑑𝑟𝑜𝑔𝑒𝑛 =𝐴𝑚𝑜𝑛𝑡 𝑜𝑓 𝐻𝑦𝑑𝑟𝑜𝑔𝑒𝑛 𝑃𝑟𝑜𝑑𝑢𝑐𝑒𝑑(LCOH)

Capital Cost ≒ Capacity×Unit Cost/Depreciation Period
Operation Cost ≒ （Electricity & Water Unit Cost）×Capacity×Operation Time
Maintenance Cost ≒ Capacity×Unit Cost×Maintenance Ratio
Amount of Hydrogen ≒ Capacity×Operation Time×Efficiency

𝐿𝐶𝑂𝐻 =

𝑈𝑛𝑖𝑡 𝐶𝑜𝑠𝑡/(𝐷𝑒𝑝𝑟𝑒𝑐𝑖𝑎𝑡𝑖𝑜𝑛 𝑃𝑒𝑟𝑖𝑜𝑑)
𝑈𝑛𝑖𝑡 𝐶𝑜𝑠𝑡 × 𝑀𝑎𝑖𝑛𝑡𝑒𝑛𝑎𝑛𝑐𝑒 𝑅𝑎𝑡𝑖𝑜−+ 𝑒 & 𝐻2𝑂 𝐶𝑜𝑠𝑡 +𝑂𝑝𝑒𝑟𝑎𝑡𝑖𝑜𝑛 𝑇𝑖𝑚𝑒 × 𝐸𝑓𝑓𝑖𝑐𝑖𝑒𝑛𝑐𝑦
𝑂𝑝𝑒𝑟𝑎𝑡𝑖𝑜𝑛 𝑇𝑖𝑚𝑒 × 𝐸𝑓𝑓𝑖𝑐𝑖𝑒𝑛𝑐𝑦

Assuming
electrolyzer Cost 100,000 JPY/kW Depreciation 10 yr 5kWh/Nm3-H2
１．Unpurchased surplus power of 400 hrs/yr（Capacity ratio = 400/(24×365) ≒ 4.6%）⇒125 JPY / Nm3-H2（Free electricity ≠ Cheap H2）※Total H2 Price @ Refueling Station ≈ 90 JPY/Nm3-H2
２．Capacity ratio of 12% ⇒ 48 JPY / Nm3-H2
National Institute for Materials ScienceFrom EU：Hybridized Power to Gas

13

0.54 €/Nm3
0.45 €/Nm3
0.49 €/Nm3
0.45 €/Nm3
0.12 €/Nm3

National Institute for Materials ScienceAn Extreme of Battery Cost ＝ 0

14

No effective solution to lower H2 Production cost from PV?
⇒Considering extremes to explore golden mean
Extreme 1: Electricity cost = 0 ⇒ No solution found so far
Extreme 2: Battery cost = 0⇒ ???
Battery Cost = 0 JPY/kWh & Efficiency = 100%
⇒Installation of infinite capacity battery!!
PV output
Charge &Discharge

Output levelized by battery
National Institute for Materials Science

Integrated PV・Battery・Electrolyzer
𝐿𝐶𝑂𝐻 =

15

𝑈𝑛𝑖𝑡 𝐶𝑜𝑠𝑡/(𝐷𝑒𝑝𝑟𝑒𝑐𝑖𝑎𝑡𝑖𝑜𝑛 𝑃𝑒𝑟𝑖𝑜𝑑)
𝑈𝑛𝑖𝑡 𝐶𝑜𝑠𝑡 × 𝑀𝑎𝑖𝑛𝑡𝑒𝑛𝑎𝑛𝑐𝑒 𝑅𝑎𝑡𝑖𝑜−+ 𝑒 & 𝐻2𝑂 𝐶𝑜𝑠𝑡 +𝑂𝑝𝑒𝑟𝑎𝑡𝑖𝑜𝑛 𝑇𝑖𝑚𝑒 × 𝐸𝑓𝑓𝑖𝑐𝑖𝑒𝑛𝑐𝑦
𝑂𝑝𝑒𝑟𝑎𝑡𝑖𝑜𝑛 𝑇𝑖𝑚𝑒 × 𝐸𝑓𝑓𝑖𝑐𝑖𝑒𝑛𝑐𝑦

Battery Cost = 0 JPY/kWh & Efficiency = 100%
⇒Installation of infinite capacity battery!!
Electrolyzer
Capacity without
battetry

PV output
Charge &Discharge

Output levelized by battery
Benefit 1：Capacity ratio⇒100%
Benefit 2：Reduction of electrolyzer capacity⇒1/7～1/8（When PV capacity ratio = 12～14%）
In real operation condition
PV 1. ⇒ electrolyzer
2. ⇒ battery ⇒ electrolyzer（charge/discharge loss）
3. ⇒ cut off

Electrolyzer
Capacity withbattetry

Need to identify condition additional
cost of battery

National Institute for Materials ScienceEssential Problem to Tackle

Battery
Cost

Reduction inElectrolyzer Cost
＆ Increased
Capacity Ratio

16

Reduction inElectrolyzer Cost
＆ Increased
Capacity Ratio
Battery
Cost

National Institute for Materials ScienceEconomically Rational Renewable H2
Conventional：Limited
communication between disciplines

Collaboration：Share Common Vision for Deep Decarbonization⇒Proposed Economically Rational H2 Production System

Systems Engineering

Experts with Different Disciplines

Focus on present system
Detailed roadmaps unaware

Battery

Tech X

Eurekalert

Large gap・Disconnection
H2・Fuel Cell

Battery
Roadmap

Tech X
Roadmap

17

H2・Fuel Cell
Roadmap

Chemistry
Material

PV Roadmap

Photovoltaic
Solar Cell

Advances in Engineering

National Institute for Materials ScienceBattery-assisted Solar H2 Production

18

水素
充電 放電
電気

電気分解

エネルギー
電気 マネジメント 電気
システム

パワコン
太陽光発電

電力
廃棄

水

酸素

[JPY/Nm3]

60
50
40

PV 7 JPY/kWhElectrolyzer 50,000 JPY/kW

30
20
10

Electricity
Lost electricity (loss1)
Electrolysis plant

Lost electricity (loss2)
Battery
Electrolysis operation& maintenance0
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20[103 JPY/kWh]National Institute for Materials ScienceBoundary for System Evaluation

19

Kikuchi et al., Int J H2
Energy, 44 (2019) 1451
Boundary of battery-assistedhydrogen production

PV
panel

EMS
DC/DC
converter

Battery
storagePEMelectrolyzer

Solar radiation
DC flow
Hydrogen flow

National Institute for Materials ScienceAlgorithm for Optimization
START

20

Kikuchi et al., Int J H2
Energy, 44 (2019) 1451

Define unit cost of electricity,
UCostelec [JPY/kWh]Define cost of electrolyzer and battery,CAPEXely, OPEXely, CAPEXbat, OPEXbat
Minimize hydrogen cost, UCostH2 [JPY/Nm3]
by capacities of PV and storage,
CapPV [kW] and Capbat [kWh],based on given unit cost of storage

Optimization
Given Constants：
Unit Capital Cost
Electrolyzer, battery
Operation Cost
Electricity,
maintenance
Design Variables：
Capacity
Electrolyzer,
Battery,PV

END
National Institute for Materials ScienceReference Costs：Electrolyzer

21

Published Roadmaps
Fuel Cells and Hydrogen Joint Undertaking、2014
1,860-2,320 EUR/kW @ 2014
250-1,270 EUR/kW @ 2030
International Energy Agency,
Technology Roadmap:
Hydrogen and fuel cells, 2015
20,000-60,000 hr(1,500-3,800 USD/kW)@ 201580,000 hr (830 USD/kW)@ 2030CO2 Free H2 Working Group, 2017
50,000 JPY/kW(385 EUR/kW or 455 USD/kW)
Settings：30,000, 50,000, 100,000 JPY/kW（Discrete Values）
National Institute for Materials ScienceReference Costs：PV

22

Published Roadmaps
NEDO PV Challenge
7~14 JPY/kWhThe SunShot Initiative’s
2030 Goal & Renewable
Power Generation Costs in 2017
3~5 JPY/kWh(0.03 ~ 0.05 USD/kWh,
110 JPY/USD)
Recent Procurement Price
Renewable Energy Project
Development Office, Saudi
Arabia.(2017)1.95 to 3.68 JPY/kWh(6.70 to 12.63 Halalas/kWh,0.291861 JPY/Halalas)
Reference Values：3, 5, 7 …JPY/kWhNational Institute for Materials ScienceReference Costs：Battery

23

Published Roadmaps
NEDO Secondary Battery Roadmap, 2013
5000 JPY/kWh at 2030
Berckmans et al., Energies, 2017
5500 JPY/kWh (50 USD/kWh) ＠ 2030
Ultimate Target of 5000 JPY/kWh assumed

National Institute for Materials ScienceObjective Functions & Method

24【Objective Function】
Hydrogen Production Cost（\/Nm3-H2）=(PV LCOE)x(PV Output)+(Capital Costs* + OPEX)*Battery & Electrolyzer
=

c∙‫׬‬

𝑡 𝑑𝑡 +A EX

ΤL+ O EX

+

A EX

ΤL

+ O EX

Major Technological Parameters Assumed
Battery： Depreciation = 20 y; Efficiency = 0.9;
OPEX = 0;
Electrolyzer： Depreciation = 10 y;
Other parameters are from WE-NET report【Optimization Method】
Non-linear Problem (Non-monotonic increase/decrease)⇒Difficult to find rigorous solution
Golden ratio division method (Kiefer,1953)
Relative Error of 0.001 allowed※Strategy to find neighborhood solution
Explore wide range of parameters space
National Institute for Materials ScienceExample25

No C-rate constraint

Electrolyzer Cost
5,000 JPY/kWPV Cost [JPY/kWh]

PV Cost [JPY/kWh]

Production of~1×104 Nm3/h[JPY/Nm3]

Kikuchi et al., Int J H2
Energy, 44 (2019) 1451

PV Cost [JPY/kWh]

Battery Cost [JPY/kWh]

PV Cost [JPY/kWh]

Battery Cost [JPY/kWh]

Battery Cost [JPY/kWh]

Battery Cost [JPY/kWh]National Institute for Materials ScienceCost Breakdown
50

60

PV：7 JPY/kWh[JPY/Nm3][JPY/Nm3]

60

40

30
20
10

Electricity
Lost electricity (loss1)
Electrolysis plant

Lost electricity (loss2)
Battery
Electrolysis operation& maintenance0
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20[103 JPY/kWh][JPY/Nm3]

60
50
40

Electricity
Lost electricity (loss1)
Electrolysis plant

Lost electricity (loss2)
Battery
Electrolysis operation& maintenance

PV：3 JPY/kWh30
20

Kikuchi et al., Int J H2 26
Energy, 44 (2019) 1451

Battery

100
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

50
40Electricity
Lost electricity (loss1)
Electrolysis plant

PV：5 JPY/kWh

Lost electricity (loss2)
Battery
Electrolysis operation& maintenance

30
20
10
0
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20[103 JPY/kWh]※Electrolyzer Cost：50,000 JPY/kW✓ Electricity cost dominant✓ Battery cost of 15,000
JPY/kWh →Change oftrendElectrolyzer（CAPEX+OPEX))PV Electricity（for electrolysis + loss）[103 JPY/kWh]National Institute for Materials ScienceCost Breakdown[JPY/Nm3]

60
50
40

Kikuchi et al., Int J H2 27
Energy, 44 (2019) 1451

Electricity
Lost electricity (loss1)
Electrolysis plant

Lost electricity (loss2)
Battery
Electrolysis operation& maintenance

30
20
10

0
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20[103 JPY/kWh]

Battery cost = Unit cost (JPY/kWh) × Installed capacity (kWh)from 20,000 JPY/kWh to 14,000 JPY/kWhInstalled capacity increases, Unit cost decreases
from 14,000 JPY/kWh to lower
Installed capacity reaches plateau, Unit cost decreases
National Institute for Materials Science[kWh-battery/kW-electrolysis]

Battery Installation

28

Kikuchi et al., Int J H2
Energy, 44 (2019) 1451

45

c

40

7 JPY/kWh
5 JPY/kWh
3 JPY/kWh35
30

Inflection zones

25
20

Electrolyzer Cost
A EX : 30,000 JPY/kW
A EX : 50,000 JPY/kW
A EX : 100,000 JPY/kW

15
10
5
0

0

5

10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100[103 JPY/kWh]Threshold for battery installation〇Cost for electrolyzer
×Electricity cost（≒PV cost）
National Institute for Materials ScienceCost Breakdown

29

Kikuchi et al., Int J H2
Energy, 44 (2019) 1451

[JPY/Nm3]

80
70

Electricity
Lost electricity (loss1)
Electrolysis plant

60
50
40

Lost electricity (loss2)
Battery
Electrolysis operation& maintenancePV 3 JPY/kWh
Battery 5,000 JPY/kWh

30
20
10
0
10 20 30 40 50 60 70 80 90 100 110 120 130 140 150[103 JPY/kWh]National Institute for Materials ScienceToward Bright Future Vision
Regional Stake-holders

Academia：Deep-decarbonation Vision
Economically Rational Renewable Hydrogen
Systems Engineering
H2・Fuel Cell

Chemistry・Material

PhotovoltaicConsumerBattery expensive！
H2・Fuel Cell expensive！

水素
電気分解

エネルギー
電気 マネジメント 電気
システム

パワコン
太陽光発電

電力
廃棄

水

Renewable
Grid connection difficulty
Decreasing benefit

Local Government
No future vision！
Infrastructure dependency on big company！
No local employment！

Battery

充電 放電
電気

30

酸素

Large Enterprises
Utility Company
Vision for business growth??
Fuel Cell Supplier
Economic benefit ??
Small market⇒Expensive

Battery Supplier
Subsidydependent！

Implementation of systems bysharing region-specific problems
creating bright future vision &transition scenario toward the vision

National Institute for Materials ScienceSummary

31○Changing landscape toward 80% GHG emission
reduction overviewed○We proposed an integrated H2 production system as an
option for massive penetration of variable renewables○Battery-assist can reduce CAPEX of Electrolyzer andincrease capacity ratio of electrolyzer〇System optimization indicates rational H2 production
by future development of component technologies

Acknowledgement
・Part of study is supported by MEXT Integrated Materials
Development project.
・Collaborators: Prof. Y. Kikuchi@UT, Prof. T. Ichikawa@Hiroshima U.,
Prof. M. Sugiyama@UT, Dr. T. Hasegawa@NISSAN, Dr. T. Haneda@Tokyo Gas
National Institute for Materials Science