Renewable Electricity Storage with Ammonia Fuel: A Case Study in Japan with Optimal Power Generation Mix Model

Transcription

1 USAEE/IAEE 35th North American Conference, Concurrent Session 19, Royal Sonesta Hotel, Houston TX USA, November 14, 217 Renewable Storage with Ammonia Fuel: A Case Study in Japan with Optimal Power Generation Mix Model Ryoichi Komiyama, Yasumasa Fujii The University of Tokyo 1

2 Contents Introduction Modelling Analysis for RE-based Ammonia Storage in Power Grid Inter-Sectoral Analysis for RE-based Ammonia: Sector & Chemical (Ammonia) Industrial Sector RE-based Ammonia vs NG-based Ammonia 2

3 Background RE-based hydrogen system has attracted keen attention for carbon reduction in Japan. e.g. Basic Energy Plan in Japan, 214 RE-based hydrogen system, however, requires massive investment. Ammonia is regarded as one of the candidates for H 2 carrier and a possible fuel, due to key properties of energy density and logistics Well-established transport and storage infrastructure already in place Availability like propane (LPG), transported easily at low pressures Relatively higher energy density than H 2 [Unit: MJ / liter] H2 (7MPa) 9, H2 (liquid) 1, NH3 (liquid) 15, Methanol 18, Ethanol 23, Propane (liquid) 29, Gasoline 36 R&D progress for direct combustion tech.(e.g. SOFC) Possible contribution for low-carbon chemical industry Possible usage for energy storage for power grid Objective: Energy modeling analysis is conducted for positioning ammonia in low-carbon power grid and energy system 3

4 Hydrogen Based Energy System MCH (Methylcyclohexane) (C 7 H 14 C 7 H 8 ) (Advantage) higher H 2 density (5 times as much as gaseous H 2 ), availability in existing gasoline infrastructure (Disadvantage) dehydrogenation (4 steam, energy loss (3%)), Bulky, need of H 2 refining for hydrogen station Liquefied Hydrogen * Commercialized in small-scale project (Advantage) higher H 2 density (8 times as much as gaseous H 2 ), no need of H 2 refining for hydrogen station, commercialized in power generation (dual fuel at H 2 7%) (Disadvantage) liquefaction(-253, energy loss (15%)), investment cost for infrastructure, boil-off (difficulty in longterm storage) Ammonia * R&D stage, Demonstration stage * Demonstration stage (Advantage) higher H 2 density (12 times as much as gaseous H 2 (-33 or 8Pa)), availability in existing LPG infrastructure, direct combustion in FC (fuel cell), cheap cost (Disadvantage) toxicity, energy loss in dehydrogenation if needed, need of H 2 refining for hydrogen station (Source) Cabinet Office, Government of Japan, SIP Pioneering the Future: Japanese Science, Technology and Innovation 215 4

5 Chemical Industry & Ammonia Market Chemical industry e.g. fertilizers, steel, plastics etc. depends on hydrocarbons for raw materials and fossil fuel for the production. faces significant challenges: growing carbon emissions, security of supply for both energy and raw materials. Carbon-free synthesis of chemicals by RE is possible option for the future. Ammonia 2% of global fossil fuel is consumed in ammonia. 9% of ammonia production is based on natural gas. 8% of ammonia is used in fertilizer industry. Fertilizer demand is growing at 3% per annum. World Ammonia Production (212): 165 million ton China: 53 million ton, Europe: 17 million ton, North America: 16 million ton, India: 14 million ton, Japan: 1.3 million ton Production today uses Haber-Bosch process, mainly on natural gas as feedstock. 5

6 Ammonia Production (Conventional Haber Bosch Process & RE based) Conventional(HB, NG-based) Gas Preparation Methane, Water(CH 4, H 2 O) H 2 O H 2 O, CO 2 Ammonia Conversion and Separation N 2 +3H 2 2 Air (O 2, N 2 ) CH 4 +H 2 O CO+3H 2 H 2 O 2CH 4 +O 2 2CO+4H 2 H 2, N 2 Separator H 2, N 2, H 2, N 2, CO 2 Reactor Cooler Catalysor H 2, N 2 Ammonia(Fluid) H 2, N 2, CO RE-based NH3(Electrolysis + HB) Gas Preparation Ammonia Conversion and Separation H 2 O Hydrogen Electrolyser H 2 N 2 +3H 2 2 H 2, N 2 H 2, N 2, Renewable Reactor Cooler Air Air Separation Unit N 2 H 2, N 2 Ammonia(Fluid) 6

7 Direct Ammonia SOFC (Solid Oxide Fuel Cell) SOFC is attractive fuel cell concepts, because of their ability to accommodate a range of fuels. SOFC conventionally runs at temperatures above 5 (typically 8-1 ), and one of the advantages of this is that the cracking process, necessary to free the hydrogen from the fuel, and the generation of electricity can be combined. Ammonia can be directly input into the SOFC without any pre-treatment. Conversion Efficiency: around 6% Ammonia Oxidation (overall reaction for complete combustion of ammonia): 4 +3O 2 2N 2 +6H 2 O Anode Electrolyte Cathode Oxygen ion-conducting DA-SOFC Utilizes inexpensive base metal catalyst (Ni or Co) Operating temperature 8-1 C, depending on electrolyte NH 3/2H 2 +1/2N N 2, H 2, 3 2 H 2 O, H 2 O 2 H 2 O O 2- V Hydrogen proton-conducting DA-SOFC Utilizes inexpensive base metal catalyst (Ni or Co) Operating temperature 45-7 C, depending on catalyst Anode Electrolyte Cathode 3/2H 2 +1/2N 2 N 2, H 2, H 2 O 2 H + H 2 O V O 2, N 2 O 2, N 2 O 2, N 2 O 2, N 2,H 2 O (F. Ishak et al, 212) 7

8 Optimal Power Generation Mix Model (OPGM) The model evaluates the installable potential of RE-based ammonia storage system in the Japanese power grid. (Reference) Komiyama, R., Fujii, Y., Energy Policy, Vol.11, pp (217) Komiyama, R., Fujii, Y, Energy, Vol.81, pp (215) Linear programming model. Single-year minimization of total electricity system cost Power grid topology: 135 nodes, 166 power lines (high-voltage) Time-resolution: 1-min hours on 365 days 52,56 time segments per year (= ) Optimal Power Generation Mix Model (OPGM) (Power plants) Construction cost Capital recovery factor Fuel cost Life time (or legal durable years) Conversion efficiency Annual average availability Seasonal peak availability Load following capability Ratio of DSS mode operation Minimum output constraints Schedule of plant maintenance Fuel supply constraints Existing power plant capacity Constraints on newly built capacity (Energy storage technology) kw kwh construction cost Cost of consumable parts Life cycle Round-trip efficiency Self discharge loss C-rate constraints Maximum kwh ratio to kw Usage ratio High Time-Resolution Optimal Power Generation Mix Model (Calculated results) Newly constructed capacity Power generation Power generation cost Fuel consumption CO 2 emissions Optimal power dispatch load curve and wind power output Carbon regulation Carbon tax Power Grid Topology and Demand in Japan 8

9 Optimal Power Generation Mix Model (OPGM),combined with RE based Ammonia Storage The model considers cost trade-off of ammonia with rechargeable battery, RE output curtailment and inter-node power transmission exchange. system Suppression Control RE based Ammonia Storage System N 2 Separation Electrolyzer N 2 H 2 O 2 Production O2 Synthesis (HB) Liquefaction Tank RE based Supply Nuclear Coal fired LNG fired Oil fired Hydro Geothermal Power Generators Power Grid NAS Battery Li ion Battery Pumped hydro Fuel Cell (SOFC) Load Energy Storage 9

10 Case Setting CO2 Regulation Base (No Regulation), 5%, 6%, 7%, 8% Cost of technology (electrolyzer, NH3 production and storage, SOFC) is assumed as -8% reduction from reference values. Nuclear, thermal, hydro, pumped, electricity demand etc. are assumed on the basis of METI s energy outlook in 23. and wind installations are endogenized (determined through the optimization) Lower limit values: (64 GW), wind (1 GW) from METI s energy outlook in 23 Upper limit values: (33 GW ), wind (26 GW) from potential survey by Ministry of Environment, Japan. 1

11 Power Generation Mix in Japan Strict CO 2 regulation policy accelerates the installations of, wind and energy storage system, such as NAS battery and storage, which replace carbon-intensive thermal power plants. Power transmission loss increases, due to nation-wide power exchange caused by massive RE integration. Installation of storage is smaller than that of NAS battery TWh Coal Base (METI 23) Power Generation (wind) CO2 5% Red. LNGCC Nuclear CO2 6% Red. CO2 7% Red. NAS NH NAS 3 storage Power trans. loss CO2 8% Red. Loss Suppressed Suppressed Ammonia() Ammonia(wind) Ammonia(out) Battery2(out) Battery1(out) Pumped(ont) Ammonia(in) Battery2(in) Battery1(in) Pumped(in) Electrolyzer Ammonia(out) & SOFC Oil LNG GCC LNG ST Coal Nuclear Marine Biomass Geothermal Hydro GW Base (METI 23) Capacity storage NAS LNGCC Coal Nuclear CO2 5% Red. CO2 6% Red. CO2 7% Red. CO2 8% Red. Ammonia storage SOFC NH3 plant (HB) Electroyzer Battery2 Battery1 Pumped Oil LNG GCC 11

12 Optimal Installation of and CO2: 8% reduction case tends to be installed in demand-intensive region such as Kanto, Kansai and Chubu which have enough power balancing resources. turbine (onshore) is introduced in the resource rich regions such as Tohoku and Kyushu. [GW] [GW] 12

13 Locational Marginal Price (LMP) of Annual Average, CO2: 8% reduction case price is lower in northern part of Japan, due to the installation of renewable energy. Nodal Price Range [yen per kwh] 13

14 Ammonia Storage Installation CO 2 regulation plays an important role to accelerate the introduction of RE based ammonia energy system. Ammonia Storage Capacity 21, ton is equal to three units of LNG bulk storage tank. Ammonia Storage Capacity in CO 2 8% Red. Case 25 2 (1, LNG ton) Base (METI 23) CO2 5% Red. CO2 6% Red. CO2 7% Red. CO2 8% Red. Ammonia Storage [GWh] (=37 [1, ton of LNG]) 14

15 Power System Operation [GW] Power System Operation [GW] Power System Operation [GW] Power System Operation [GW] Power Dispatch in May CO 2 : -8% reduction case Hokkaido Tohoku Tokyo Kyushu Aug.1 (out) & SOFC -2 (wind) (wind) storage NAS Power Interchange Suppressed (wind) NAS storage NAS Power Interchange Suppressed Suppressed Pumped(out) NAS storage LNGCC Pumped(in) NAS Suppressed (wind) Suppressed () LNGCC Power Interchange Suppressed NAS (out) & SOFC Loss Inter Change Suppressed Suppressed Ammonia() Ammonia(wind) Battery2(out) Battery1(out) Pumped(ont) Ammonia(in) Battery2(in) Battery1(in) Pumped(in) Ammonia(out) & SOFC Oil LNG GCC LNG ST Coal Nuclear Marine Biomass Geothermal Hydro Load Loss Inter Change Suppressed Suppressed Ammonia() Ammonia(wind) Battery2(out) Battery1(out) Pumped(ont) Ammonia(in) Battery2(in) Battery1(in) Pumped(in) Ammonia(out) & SOFC Oil LNG GCC LNG ST Coal Nuclear Marine Biomass Geothermal Hydro Load Loss Inter Change Suppressed Suppressed Ammonia() Ammonia(wind) Battery2(out) Battery1(out) Pumped(ont) Ammonia(in) Battery2(in) Battery1(in) Pumped(in) Ammonia(out) & SOFC Oil LNG GCC LNG ST Coal Nuclear Marine Biomass Geothermal Hydro Load Loss Inter Change Suppressed Suppressed Ammonia() Ammonia(wind) Battery2(out) Battery1(out) Pumped(ont) Ammonia(in) Battery2(in) Battery1(in) Pumped(in) Ammonia(out) & SOFC Oil LNG GCC LNG ST Coal Nuclear Marine Biomass Geothermal Hydro Load 15

16 25 Annual SOC of Storage in Japan CO 2 : -8% reduction case Round trip efficiency of storage is not good, and it is not suitable for a daily cycle. Charge and discharge cycle of storage tank shows a monthly or seasonal cycle, while that of NAS battery exhibits a daily cycle. Since a storage loss of tank is very low, the model selects a long term storage of surplus RE output as an optimal solution under strict CO 2 regulation. SOC of storage tank and battery Ammonia is a suitable option for a long-term storage of RE energy. Stored [GWh] Jan 1 Feb 1 Mar NAS Battery 1 Apr 1 May 1 Jul 1 Jun Jan.,1 Feb.,1 Mar.,1 Apr.1 May,1 Jun.,1 Jul.,1 Aug.,1 Sep.,1 Oct.,1 Nov.,1 Dec.,1 Dec.,31 1 Aug 1 Sep 1 Oct 1 Nov 1 Dec 31 Dec Pumped NaS Li ion Ammonia 16

17 Inter Sectoral Analysis for RE based Ammonia ( Sector & Chemical Industrial Sector) Optimal Power Generation Mix Model, combined with RE-based Ammonia and Conventional (NG-based) Ammonia Supply Chemical Industrial Sector Sector (Ammonia) Suppression Control Ammonia Storage System integrated with VRs N 2 Separation N 2 Synthesis (HB) RE based Supply Demand: 1.3 mil. ton Nuclear Coal fired LNG fired Oil fired Hydro Geothermal system Power Grid Electrolyzer H 2 O 2 Production Liquefaction O2 Fuel Cell (SOFC) Load Tank Demand Haber Bosch (HB) Process CH 4 Natural Gas Conventional Supply Power Generators NAS Battery Li ion Battery Pumped hydro CO 2 Coefficient of : 1.6 t/t- Price: 57 $/t- Energy Storage 17

18 RE based & Conventional (NG based) Ammonia CO 2 Regulation for Total Emissions of both & Chemical Sectors BAU (No Regulation), 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8% Which is economically affordable option under carbon regulation? Carbon regulation, around after CO 2 4% reduction case, encourages RE-based supply Ammonia Sales Composition Ammonia Production [1 ton] Conventional (NG based) BAU 1% 2% red 3% 4% RE based 5% 6% CO2 Regulation Scenario 7% 8% RE based NH3 Conventional NH3 18

19 CO 2 Price (Shadow Price) Carbon price shows accelerative increase as severe carbon regulations are assigned. e.g. Carbon Price: 2 [$/t] LNG Price: +11 [$/MMBtu] LNG Price in Japan (215): 9.3 [$/MMBtu] 2 [$/MMBtu] Carbon Price: 16 [$/t] LNG Price: +89 [$/MMBtu] LNG Price in Japan (215): 9.3 [$/MMBtu] 98 [$/MMBtu] CO 2 Price (CO 2 Shadow Price) CO2 Marginal Price [$/t] % 2% red 3% 4% 5% 6% 7% 8% CO2 Regulation Scenario 19

20 Summary CO 2 regulation are prerequisite for promoting RE based ammonia Severe carbon regulation potentially replaces conventional ammonia supply with RE based ammonia Ammonia is a suitable option for a long term storage of RE energy, such as in a seasonal or monthly cycle. RE based ammonia is not dominant even under severe carbon regulation, due to its competition with rechargeable battery and other measures such as internode power exchange. 2

21 Thanks for your kind attention. Ryoichi Komiyama Associate Professor The University of Tokyo Acknowledgment This work was supported by JSPS KAKENHI Grant Number JP17H3531, JP15H1785, and by the Environment Research and Technology Development Fund of the Environmental Restoration and Conservation Agency. 21

22 and Potential in Japan estimated by Ministry of Environment, Japan Upper limit of and wind in each node is set by using those potential estimations by Ministry of Environment, Japan [GW] [GW] 22

23 , and Production In CO 2 8% reduction case, 1% of wind output is utilized production. -based is observed in Tohoku, Kyushu and Hokkaido. is not so much produced from output. In Kyushu, however, 3% of output is utilized for production. (Japan) (by region, CO 2-8%) 35 TWh Base (METI 23) (Japan) 3 TWh CO2 5% Red. CO2 6% Red. CO2 7% Red. CO2 8% Red. Base (METI 23) CO2 5% Red. CO2 6% Red. CO2 7% Red. CO2 8% Red Suppressed Ammonia(wind) TWh Hokkaido Tohoku Kanto Chubu Hokuriku Kansai Shikoku Chugoku Kyushu (by region, CO 2-8%) 1 TWh 8 Suppressed NH Ammonia() Hokkaido Tohoku Kanto Chubu Hokuriku Kansai Shikoku Chugoku Kyushu Suppressed Ammonia(wind) Suppressed Ammonia() 23