USAEE/IAEE 36th North American Conference, Concurrent Session 28, Hilton Crystal City, Washington DC USA, September 25, 2018 Modelling Analysis for imal Integration of Solar PV in National Power Grid of Japan Ryoichi Komiyama, Yasumasa Fujii The University of Tokyo
Outline Backgrounds: PV Status in Japan Methodology: imal Power Generation Mix Model Single-year optimization (cost minimization) 352 buses, 441 transmission lines with 8,760 time slices per year Scenario & Results: imal Integration of Solar PV Conclusions and Implications 2
Status of Solar PV in Japan Installed PV Capacity in Japan (2017) Installed PV capacity in Japan is the third largest in the world at 2017. Hokkaido 40 GW or more is already installed, and another 40GW is planned to be installed for the future (peak demand in Japan, 150 GW). Penetration of PV capacity was particularly Tohoku encouraged by FIT (feed-in-tariff) implemented in 2012 Hokuriku Majority of the install is utility-scale PV. Chugoku Kansai Chubu Kanto Kyushu Shikoku (Source) Compiled from the data of Ministry of Economy, Trade and Industry <http://www.enecho.meti.go.jp/category/saving_and_new/saiene/kaitori/> 3
Impact of Solar PV in Japan In Kyusyu area (15GW), PV output recorded 82% of power demand in April 29, 2018, while 80% is observed in May 5, 2018 in Shikoku area (10GW) The Japanese rule of renewable priority dispatch: Dispatchable thermal (online) pumped-hydro Dispatchable thermal (not online) interconnection curtailing biomass curtailing PV & Wind contingency balancing order curtailing inflexible resource (nuclear, geothermal, hydro). Power Generation[GW] 14 12 10 8 6 4 2 0-2 -4-6 Dispatch in Kyushu, Japan from April 24 to April 30 in 2018 PV Output: 6.4GW (82% of Power Demand) 12pm Apr 24 Apr 25 Apr 26 Apr 27 Apr 28 Apr 29 Apr 30 2018 (Source) Compiled from the data of Kyushu Electric Power Company Inter Change Suppressed PV Suppressed Wind Pumped(out) Pumped(in) PV Wind Thermal Biomass Hydro Geothermal Nuclear Load 4
Research Background In specific service area, enough grid capacity will not be secured to manage PV output Installed PV capacity is more than or comparable to that of power grid in specific area, while PV capacity is well less than the scale of power grid in some area. imal deployment of solar PV is important for addressing regional imbalances between the scale of power grid and that of PV. This presentation attempts to optimize planned 40GW of PV deployment (light orange) (Now in Japan, 40 GW is already installed, and another 40GW is planned to be installed) Installed and Planned PV capacity, with Grid Capacity (Peak Demand) Peak demand or capacity [GW] 60 50 40 30 20 10 0 Peak Demand Already Installed PV Planned PV (Source) Compiled from the data of METI and OCCTO 5
imal Power Generation Mix Model in Japan Geographical Resolution: 352 buses, 441 bulk power transmission lines (HVAC:435 lines, HVDC:6 lines) Temporal Resolution: An hourly resolution for 1 year = 8,760 time slices / year Method: LP model from scratch, Single-year cost min. (operating cost + battery install cost) Scale of LP Model: Constraints: 62 millions, Endogenous variables: 44 millions Bus system diagram in Japan, 352 nodes and 441 bulk power transmission lines Western Japan (60Hz) Eastern Japan (50Hz) (Related Works) Komiyama R, Fujii Y, Energy Policy ;66:73-89 (2014) Komiyama R, Fujii Y, Energy ;81:537 555 (2015) Komiyama R, Fujii Y, Energy Policy ;101:594-611 (2017) 6
Grid Topology (352 nodes, 441 power transmission lines ) Consideration of grid topology is important in Japan Longitudinal-type grid topology, different from mesh-type topology like Europe Similar power generation mix in each service area few incentive to regional power exchange & national resource consolidation Insufficient interconnection capacities among 9 service areas Inherently difficult to integrate large-scale RES 7
PV Capacity Factor in 352 buses Annual-average Capacity Factor of Solar PV Capacity factor of solar PV assessed in 352 buses, from AMeDAS database (official meteorological database) PV capacity factor tends to be lower in the northern part of Japan. As implied, the better strategy is to integrate solar PV in the bus where the capacity factor is higher and to minimize the installed PV capacity and the associated install cost. Chugoku Kansai Hokuriku Hokkaido Tohoku Kyushu Shikoku Chubu Kanto 8
Power System Resources Power system resources are set by long-term power supply plan of government and utilities Coal, LNG-GCC, LNG-ST, Oil, Nuclear, Hydro, Geothermal, Biomass, Marine, PV, Wind Pumped-hydro Storage, Sodium-sulfur (NAS) Battery (Lower C-rate), Li-ion Battery (Higher C-rate) Given capacities, except for rechargeable battery Fixed power transmission capacity Fixed load curve PV, wind outputs in 10-min estimated from official meteorological database in 352 nodes Nuclear, consistent with official target Assumptions of Power System Resources [GW] 9
Scenario of PV Integration (2 Scenarios) Japanese power generation cost is currently the highest all over the world, and the economically efficient integration of solar PV is very important Planned 40 GW of PV will enormously affect the national power system The motivation is to understand Where is the best location of PV to be installed in the power grid? erence Scenario () Most possible projection of PV deployment in Japan PV, 40GW, is to be installed into the location as already announced. imal Integration Scenario () Deployment of PV capacity to be installed, 40GW, into each node is optimized, so as to minimize the total power system cost 10
imal Integration of PV capacity In scenario, nodal PV deployment shifts to the area with larger grid capacity and with higher capacity factor of solar PV, compared with scenario. Hokkaido Hokkaido Hokuriku Tohoku Hokuriku Tohoku Kyushu Chugoku Kansai Shikoku Chubu Kanto Kyushu Chugoku Kansai Shikoku Chubu Kanto 11
Effect of imal PV integration PV capacity [GW] PV deployment in shifts to the area with sufficient grid capacity, higher solar radiation and higher wholesale electricity price to further cost minimization. For example, PV install in higher solar insolation leads to reduce the required PV capacity for gaining the same amount of PV power and to save the PV investment cost. Difference of results between and Total 6GW less PV capacity in Total 100 billion yen of PV investment can be saved in Total 80 billion yen of fossil fuel cost is conserved in Total 1.3TWh of electricity transmission loss can be reduced in 40 35 30 25 20 15 10 5 0 PV capacity in 9 service area Existing increase To be installed Hokkaido Tohoku Kanto Chubu Hokuriku Kansai Shikoku Chugoku Kyushu decrease Total System Cost [trillion yen/year] Total Power System Cost 10.10 10.05 10.00 9.95 9.90 9.85 Total System Cost 12
Locational Marginal Price (LMP) imal deployment of PV encourage PV install shifted to Kanto and Chubu area from the most of other regions Wholesale price decreases in the area where PV capacity is incremented, while the price increases in the area where the PV capacity is decremented Regional gap of area price is reduced. Locational Marginal Price (LMP) in 352 buses () Kyushu Chugoku Kansai Shikoku Hokuriku Chubu Hokkaido Kanto Tohoku Annual-Average LMP (wholesale Price) in 9 service area (, ) [yen/kwh] 12 increase decrease 10 8 6 4 2 0 13
Wholesale Electricity Price & imal Dispatch in Kanto 12 Increased PV output reduces wholesale price in around noon and night. Wholesale price in night is reduced by electricity discharged from pumped-hydro charged by PV in daytime [yen/kwh] Wholesale Price in Kanto from July 16 to July 20 Power System Operation [GW] 10 8 6 50 40 30 20 10 0-10 -20 1 4 7 10 13 16 19 22 1 4 7 10 13 16 19 22 1 4 7 10 13 16 19 22 1 4 7 10 13 16 19 22 1 4 7 10 13 16 19 22 July 16 July17 July 18 July 19 July 20 imal Dispatch in Kanto from July 16 to July 20 () July 16 July 17 July 18 July 19 July 20 Loss Inter Change Suppressed PV Suppressed Wind Battery2(out) Battery1(out) Pumped(ont) Battery2(in) Battery1(in) Pumped(in) PV Wind Oil LNG GCC LNG ST Coal Nuclear Marine Biomass Geothermal Hydro 14 Load
Conclusions imal PV integration will serves as a supportive material to discuss a preferable energy policy to expand more massive solar PV in future power generation mix with minimizing power system cost. Recommendation for electricity market in Japan, so that PV power generator can recognize the best location for the integration. Zoning information of the preferable location of PV integration LMP-based electricity trade 15
Thanks for your kind attention. Ryoichi Komiyama Dept. of Nuclear Engineering & Management The University of Tokyo Acknowledgment This work was supported by JSPS KAKENHI Grant Number JP17H03531, JP15H01785, and by the Environment Research and Technology Development Fund 2-1704 of the Environmental Restoration and Conservation Agency. 16