process,year,from,from_amount,from_unit,to,to_amount,to_unit,efficiency,comment,source
seawater desalination,all,electricity,0.003,MWh,water,1,m^3,333.333333333333,Desalination using SWRO. Assume medium salinity of 35 Practical Salinity Units (PSUs) = 35 kg/m^3.,"Caldera et al 2016: Local cost of seawater RO desalination based on solar PV and windenergy: A global estimate. (https://doi.org/10.1016/j.desal.2016.02.004), Fig. 4."
electrolysis,all,water,9,m^3,hydrogen (g),33.3333,MWh_LHV,3.7037,Based on ideal conversion process of stochiometric composition.,-
electrolysis,2020,electricity,50.1252,MWh,hydrogen (g),33.3333,MWh_LHV,0.665,,
electrolysis,2030,electricity,49.0196,MWh,hydrogen (g),33.3333,MWh_LHV,0.68,Alkaline electrolysis AEC. May potentially increase to 70-80% in the future.,"DEA (2021): Technology Data for Renewable Fuels, pg. 97."
electrolysis,2040,electricity,46.62,MWh,hydrogen (g),33.3333,MWh_LHV,0.715,,
electrolysis,2050,electricity,44.4444,MWh,hydrogen (g),33.3333,MWh_LHV,0.75,,
battery inverter,all,electricity,1,MWh,battery,0.979795897113271,MWh,0.979795897113271,from DEA technology assumptions via technology-data repository,DEA
battery inverter,all,battery,1,MWh,electricity,0.979795897113271,MWh,0.979795897113271,from DEA technology assumptions via technology-data repository,DEA
HVDC inverter pair,all,electricity,1,p.u.,hvdc,0.99,p.u.,0.99,Losses for voltage source converters (VSCs). Line commutated converters (LLC) would be lower ~0.7%.,d’Amore-Domenech et al (2021): 10.1016/j.apenergy.2021.116625 .
HVDC inverter pair,all,hvdc,1,p.u.,electricity,0.99,p.u.,0.99,Losses for voltage source converters (VSCs). Line commutated converters (LLC) would be lower ~0.7%.,d’Amore-Domenech et al (2021): 10.1016/j.apenergy.2021.116625 .
HVDC overhead,all,hvdc,1,p.u.,hvdc submarine,0.977,p.u.,0.977,Per 1000 km HVDC submarine line. Based on 7% losses for 3000 km.,Purvins et al. (2018): https://doi.org/10.1016/j.jclepro.2018.03.095 .
HVDC submarine,all,hvdc submarine,1,p.u.,hvdc,0.977,p.u.,0.977,Per 1000 km HVDC submarine line. Based on 7% losses for 3000 km.,Purvins et al. (2018): https://doi.org/10.1016/j.jclepro.2018.03.095 .
dummy hydrogen transport between exporter and importer,all,hydrogen (g),1,p.u.,hydrogen (g),1,p.u.,1,Dummy transport process to connect two buses directly.,None.
H2 (g) pipeline,all,hydrogen (g) compressed,1,p.u.,hydrogen (g) compressed submarine,0.979,p.u.,0.979,"Is 2.1%/1000km. Assuming self-consumption of H2 for boosting, 6000 MW_HHV H2 pipeline.","Danish Energy Agency, Technology Data for Energy Transport (2021), Excel datasheet: H2 140."
H2 (g) submarine pipeline,all,hydrogen (g) compressed submarine,1,p.u.,hydrogen (g) compressed,0.979,p.u.,0.979,2.1%/1000km. Assumed per 1000km here including H2 consumption for booster stations for 6000 MW_HHV pipeline.,"Danish Energy Agency, Technology Data for Energy Transport (2021), Excel datasheet: H2 140."
H2 (g) fill compressor station,all,hydrogen (g),1,p.u.,hydrogen (g) compressed,0.979,p.u.,0.979,Is 2.1%/1000km. Assuming self-consumption of H2 for filling compressors.,"Danish Energy Agency, Technology Data for Energy Transport (2021), Excel datasheet: H2 140."
H2 (g) pipeline decompressor,all,hydrogen (g) compressed,1,p.u.,hydrogen (g),1,p.u.,1,Arbitrary componenet for degrading gas pipeline content to regular hydrogen (g) bus.,Guess.
industrial heat pump medium temperature,all,electricity,1,MW,heat,3,MW_th,3,"based on DEA technology data catalogue for industrial process heat (302, pg. 48, 2020). Conservative for ~20°C → ~100°C .",DEA
direct air capture,all,electricity,0.4,MWh,CO2 (g),1,t,2.5,"0.4 MWh based on Beuttler et al (2019) for Climeworks LT DAC, alternative value: 0.182 MWh based on Breyer et al (2019). Should already include electricity for water scrubbing and compression (high quality CO2 output).","Beuttler et al (2019), alternative:  Breyer et al (2019)."
direct air capture,all,heat,1.6,MWh_th,CO2 (g),1,t,0.625,"Thermal energy demand. Provided via air-sourced heat pumps. 1.6 MWh based on Beuttler et al (2019) for Climeworks LT DAC, alternative value: 1.102 MWh based on Breyer et al (2019).","Beuttler et al (2019), alternative:  Breyer et al (2019)."
CH4 (g) pipeline,all,methane (g) compressed,1,p.u.,methane (g) compressed submarine,0.975,p.u.,0.975,Per 1000km for losses and boosting. Based on 0.4%/100 miles estimate.,"Asia Pacific Energy Research Centre (2000): https://aperc.or.jp/file/2010/9/26/Natural_Gas_Infrastructure_Development_Northeast_Asia_2000.pdf , Table 49."
CH4 (g) submarine pipeline,all,methane (g) compressed submarine,1,p.u.,methane (g) compressed,0.975,p.u.,0.975,Per 1000km for losses and boosting. Based on 0.4%/100 miles estimate.,"Asia Pacific Energy Research Centre (2000): https://aperc.or.jp/file/2010/9/26/Natural_Gas_Infrastructure_Development_Northeast_Asia_2000.pdf , Table 49."
CH4 (g) fill compressor station,all,methane (g),1,p.u.,methane (g) compressed,0.975,p.u.,0.975,"Assume same value as for booster stations, need to provide initial pressure increase.",Guesstimate.
CH4 (g) pipeline decompressor,all,methane (g) compressed,1,p.u.,methane (g),1,p.u.,1,Arbitrary componenet for degrading gas pipeline content to regular methane (g) bus.,Guesstimate.
methanation,all,CO2 (g),2.75,t,methane (g),13.8888,MWh_LHV,5.05047272727273,Based on ideal conversion process of stochiometric composition (1 t CH4 contains 750 kg of carbon).,
methanation,all,hydrogen (g),17.8062,MWh_LHV,methane (g),13.8888,MWh_LHV,0.779997978232301,Additional H2 required for methanation process (2x H2 amount compared to stochiometric conversion).,"Götz et al. (2016), fig. 11 ."
H2 liquefaction,all,hydrogen (g),33.3333,MWh_LHV,hydrogen (l),32.78330055,MWh_LHV,0.9835,'= 1.65% losses.,"Heuser et al. 2019: https://doi.org/10.1016/j.ijhydene.2018.12.156, table 1."
H2 liquefaction,all,electricity,6.78,MWh,hydrogen (l),33.3333,MWh_LHV,4.91641592920354,"6.78 kWh/kg_H2, considering H2 with LHV of 33.3333 MWh/t","Heuser et al. 2019: https://doi.org/10.1016/j.ijhydene.2018.12.156, table 1."
H2 evaporation,all,hydrogen (l),1,MWh_LHV,hydrogen (g),1,MWh_LHV,1,,"Heuser et al. 2019: https://doi.org/10.1016/j.ijhydene.2018.12.156, table 1."
H2 evaporation,all,electricity,0.6,MWh,hydrogen (g),33.3333,MWh_LHV,55.5555,.6 kWh/kg_H2,"Heuser et al. 2019: https://doi.org/10.1016/j.ijhydene.2018.12.156, table 1."
CH4 liquefaction,all,methane (g),13.8888,MWh_LHV,methane (l),1,t,0.072000460802949,"For refrigeration cycle, cleaning of gas presumed unnecessary as it should be nearly pure CH4 (=SNG). Assuming energy required is only electricity which is for Table 3 in the source provided with efficiencies of ~50% of LHV, making the numbers consistent with the numbers in Table 2.","Pospíšil et al. 2019: https://doi.org/10.1016/j.rser.2018.09.027 , Table 2 and Table 3."
CH4 liquefaction,all,electricity,0.5,MWh,methane (l),1,t,2,"Assuming 0.5 MWh/t_CH4 for refigeration cycle based on Table 2 of source; cleaning of gas presumed unnecessary as it should be nearly pure CH4 (=SNG). Assuming energy required is only electricity which is for Table 3 in the source provided with efficiencies of ~50% of LHV, making the numbers consistent with the numbers in Table 2.","Pospíšil et al. 2019: https://doi.org/10.1016/j.rser.2018.09.027 , Table 2 and Table 3. Source 2: https://encyclopedia.airliquide.com/methane (2021-02-10)."
CH4 evaporation,all,methane (l),1,t,methane (g),13.611024,MWh_LHV,13.611024,98% efficiency.,"Pospíšil et al. 2019: https://doi.org/10.1016/j.rser.2018.09.027 , Fig. 14."
Haber-Bosch,all,electricity,1.2777,MWh,ammonia (g),5.1666,MWh_LHV,4.04367222352665,Assume 5 GJ/t_NH3 for compressors and NH3 LHV = 5.16666 MWh/t_NH3.,"DECHEMA 2017: DECHEMA: Low carbon energy and feedstock for the European chemical industry , table 11."
Haber-Bosch,all,nitrogen (g),0.825,t_N2,ammonia (g),5.1666,MWh_LHV,6.26254545454546,".33 MWh electricity are required for ASU per t_NH3, considering 0.4 MWh are required per t_N2 and LHV of NH3 of 5.1666 Mwh.","DECHEMA 2017: DECHEMA: Low carbon energy and feedstock for the European chemical industry , pg. 57."
Haber-Bosch,all,hydrogen (g),5.9333274,MWh_LHV,ammonia (g),5.1666,MWh_LHV,0.870776151675028,"178 kg_H2 per t_NH3, LHV for both assumed.","DECHEMA 2017: DECHEMA: Low carbon energy and feedstock for the European chemical industry , pg. 57."
air separation unit,all,electricity,0.25,MWh,nitrogen (g),1,t_N2,4,"For consistency reasons use value from Danish Energy Agency. DEA also reports range of values (0.2-0.4 MWh/t_N2) on pg. 288. Other efficienices reported are even higher, e.g. 0.11 Mwh/t_N2 from Morgan (2013): Techno-Economic Feasibility Study of Ammonia Plants Powered by Offshore Wind .","Danish Energy Agency, Technology Data for Renewable Fuels (04/2022), pg.288 ."
NH3 liquefaction,all,ammonia (g),1,p.u.,ammonia (l),1,p.u.,1,,
NH3 liquefaction,all,electricity,0.001,p.u.,ammonia (l),1,p.u.,1000,0.1% of energy content of ammonia required for refrigeration.,Dias et al. 2020: https://www.frontiersin.org/articles/10.3389/fmech.2020.00021/full
NH3 evaporation,all,ammonia (l),1,p.u.,ammonia (g),1,p.u.,1,guess. TODO: check.,
LOHC hydrogenation,all,LOHC (unloaded),0.944,t,LOHC (loaded),1,t,1.05932203389831,LOHC (DBT) has loaded only 5.6%-wt H2 as rate of discharge is kept at ca. 90%.,
LOHC hydrogenation,all,electricity,0.2,MWh,LOHC (loaded),51.6604,t,258.302,"Flow in figures shows 0.2 MW for 114 MW_HHV = 96.4326 MW_LHV = 2.89298 t hydrogen. At 5.6 wt-% effective H2 storage for loaded LOHC (H18-DBT), corresponds to 51.6604 t loaded LOHC .","Niermann et al 2019: https://pubs.rsc.org/en/content/articlelanding/2019/ee/c8ee02700e , fig. 6A ."
LOHC hydrogenation,all,hydrogen (g),1.8666648,MWh_LHV,LOHC (loaded),1,t,0.535714821429107,Considering 5.6 wt-% H2 in loaded LOHC and LHV of H2.,"Runge et al 2020, pg. 7, https://papers.ssrn.com/abstract=3623514"
LOHC dehydrogenation,all,LOHC (loaded),1,t,hydrogen (g),1.34269199064,MWh_LHV,1.34269199064,"1t loaded LOHC (H18-DBT) contains 5.6 wt-% H2 (=0.056 t_H2). Considering LHV and worst case assumption: Dehydrogenation heat has to be provided by burning hydrogen (no other heat source available, loss of H2 due to burning are 28.07%). The small electricity demand (power = 0.2 MW) from the source also already included, which seems reasonable as in the source the energy flow is missing 1 MW_HHV of hydrogen which is enough to provide this electricity).","Niermann et al 2019: https://pubs.rsc.org/en/content/articlelanding/2019/ee/c8ee02700e , fig. 6A and for depth-of-discharge: Runge et al 2020, pg. 7, https://papers.ssrn.com/abstract=3623514 ."
LOHC dehydrogenation,all,LOHC (loaded),1,t,LOHC (used),0.944,t,0.944,Considering 5.6 wt-% H2 in loaded LOHC and LHV of H2.,"Runge et al 2020, pg. 7, https://papers.ssrn.com/abstract=3623514"
methanolisation,all,hydrogen (g),6.2999937,MWh_LHV,methanol,5.5361,MWh_LHV,0.878746910492942,"189 kg_H2 per t_MeOH, LHV for both assumed.","DECHEMA 2017: DECHEMA: Low carbon energy and feedstock for the European chemical industry , pg. 64."
methanolisation,all,CO2 (g),1.373,t,methanol,5.5361,MWh_LHV,4.03211944646759,,"DECHEMA 2017: DECHEMA: Low carbon energy and feedstock for the European chemical industry , pg. 66."
methanolisation,all,electricity,1.5,MWh,methanol,5.5361,MWh_LHV,3.69073333333333,,"DECHEMA 2017: DECHEMA: Low carbon energy and feedstock for the European chemical industry , pg. 65."
LOHC (loaded) loading,all,LOHC (loaded),1,p.u.,berth,1,p.u.,1,"Auxiliary process: Unloading / loading of LOHC (loaded/unloaded) happen at the same time, assume no losses as handling of LOHC is rather simple.",n/a
LOHC (loaded) unloading,all,berth,1,p.u.,LOHC (loaded),1,p.u.,1,"Auxiliary process: Unloading / loading of LOHC (loaded/unloaded) happen at the same time, assume no losses as handling of LOHC is rather simple.",n/a
LOHC (used) loading,all,LOHC (used),1,p.u.,berth LOHC (used),1,p.u.,1,"Auxiliary process: Unloading / loading of LOHC (loaded/unloaded) happen at the same time, assume no losses as handling of LOHC is rather simple.",n/a
LOHC (used) unloading,all,berth LOHC (used),1,p.u.,LOHC (used),1,p.u.,1,"Auxiliary process: Unloading / loading of LOHC (loaded/unloaded) happen at the same time, assume no losses as handling of LOHC is rather simple.",n/a
LOHC treatment,all,LOHC (used),1,p.u.,LOHC (unloaded),0.9999,p.u.,0.9999,"A 0.01% penalty, as ca. 0.01% of LOHC have to be exchanged after each loading/unloading cycle.","Runge et al 2020, pg. 7, https://papers.ssrn.com/abstract=3623514"
ship loading,all,methanol,5.5361,MWh_LHV,berth,1,t,0.180632575278626,Auxiliar process: converting between MWh_LHV and weight for shipping purposes.,n/a
ship unloading,all,berth,1,t,methanol,5.5361,MWh_LHV,5.5361,Auxiliar process: converting between MWh_LHV and weight for shipping purposes.,n/a
ship loading,all,ammonia (l),5.1666,MWh_LHV,berth,1,t,0.193550884527542,Auxiliar process: converting between MWh_LHV and weight for shipping purposes.,n/a
ship unloading,all,berth,1,t,ammonia (l),5.1666,MWh_LHV,5.1666,Auxiliar process: converting between MWh_LHV and weight for shipping purposes.,n/a
ship loading,all,hydrogen (l),33.3333,MWh_LHV,berth,1,t,0.03000003000003,"Liquid hydrogen is accounted for with LHV, for shipping it is accounted for in t. Auxiliar process for shipping purposes.",n/a
ship unloading,all,berth,1,t,hydrogen (l),33.3333,MWh_LHV,33.3333,"Liquid hydrogen is accounted for with LHV, for shipping it is accounted for in t. Auxiliar process for shipping purposes.",n/a
ship loading,all,methane (l),1,t,berth,1,t,1,Auxiliar process: converting between MWh_LHV and weight for shipping purposes.,n/a
ship unloading,all,berth,1,t,methane (l),1,t,1,Auxiliar process: converting between MWh_LHV and weight for shipping purposes.,n/a
CO2 liquefaction,all,CO2 (g),1,t,CO2 (l),1,t,1,"Assuming a pure, humid, low-pressure input stream. Neglecting possible gross-effects of CO2 which might be cycled for the cooling process.",Mitsubish Heavy Industries Ltd. and IEA (2004): https://ieaghg.org/docs/General_Docs/Reports/PH4-30%20Ship%20Transport.pdf .
CO2 liquefaction,all,heat,0.006666666666667,MWh,CO2 (l),1,t,149.999999999993,For drying purposes.,Mitsubish Heavy Industries Ltd. and IEA (2004): https://ieaghg.org/docs/General_Docs/Reports/PH4-30%20Ship%20Transport.pdf .
CO2 liquefaction,all,electricity,0.123,MWh,CO2 (l),1,t,8.13008130081301,,Mitsubish Heavy Industries Ltd. and IEA (2004): https://ieaghg.org/docs/General_Docs/Reports/PH4-30%20Ship%20Transport.pdf .
CO2 evaporation,all,CO2 (l),1,t,CO2 (g),1,t,1,,
H2 storage compressor,all,hydrogen (g),1,MWh_LHV,hydrogen (g) storage,1,MWh_LHV,1,,
H2 storage compressor,all,electricity,4,MWh,hydrogen (g) storage,33.3333,MWh_LHV,8.333325,Storing into low pressure (<200 bar) type I tanks.,"DEA technology data for energy storage, pg. 82 ."
H2 storage unstoring,all,hydrogen (g) storage,1,MWh_LHV,hydrogen (g),1,MWh_LHV,1,Reverse connection (auxiliary object) for H2 (g) compressed storage.,
H2 storage storing,all,hydrogen (g),1,MWh_LHV,hydrogen (g) storage,1,MWh_LHV,1,"Auxiliary link for storing to hydrogen gaseous storage. Used e.g. in conjunction with H2 tanks being filled directly by electrolysis (already pressurised), where the H2 tank is not filled with a compressor to high pressur e.g. 200bars, but only to 30-60 bar.",n/a
MeOH storing and unstoring,all,methanol,4.3845912,MWh_LHV,methanol storage,1,m^3,0.228071433432608,"Storage units are usually per m^3, component for unit conversion. Based on LHV and density of 792 kg/m^3 .",
CH4 storage compressor,all,methane (g),2.32997222222222,MWh_LHV,methane (g) storage,1,m^3,0.429189666066596,Assuming methane density of 167.758 kg/m^3 at 200 bar and LHV of 50 MJ/kg .,https://www.unitrove.com/engineering/tools/gas/natural-gas-density (2021-02-10).
CH4 storage compressor,all,electricity,0.1939701875,MWh,methane (g) storage,1,m^3,5.15543142422338,Assuming ca. 7.5% of HHV (55.50 MJ/kg) based on multi-stage adiabatic compression and density of 167.758 kg/m^3 .,"e.g. Bossel and Eliasson, “Energy and the Hydrogen Economy”, pg. 10f. (https://afdc.energy.gov/files/pdfs/hyd_economy_bossel_eliasson.pdf , 10.02.2021)"
CH4 storage unstoring,all,methane (g) storage,1,m^3,methane (g),2.32997222222222,MWh_LHV,2.32997222222222,Reverse connection (auxiliary object) for CH4 (g) compressed storage.,https://www.unitrove.com/engineering/tools/gas/natural-gas-density (2021-02-10).
CH4 (l) storing and unstoring,all,methane (l),0.42236,t,methane (l) storage,1,m^3,2.36764845155791,"Auxiliary efficiency. Storage units are usually per m^3, component for unit conversion. Based on density of  422.36 kg/m^3.",https://encyclopedia.airliquide.com/methane (2021-02-10).
Fischer-Tropsch,all,hydrogen (g),0.995,MWh_LHV,FT fuel,0.56,MWh_LHV,0.562814070351759,"Output is 0.7 MWh product equivalent, we’re neglecting 20% end products after upgrade: LPG and other fuel gases – we’re only looking at liquid products here.",DEA technology data for Renewable fuels (2018): Hydrogen to Power.
Fischer-Tropsch,all,electricity,0.005,MWh,FT fuel,0.56,MWh_LHV,112,"Assuming limited CO2 conversion efficiency; can theoretically be improved upon. Output is 0.7 MWh product equivalent, of which we’re neglecting 20% end products after upgrade: LPG and other fuel gases – we’re only looking at liquid products here.",DEA technology data for Renewable fuels (2018): Hydrogen to Power.
Fischer-Tropsch,all,CO2 (g),3.9,t,FT fuel,9.6,MWh_LHV,2.46153846153846,"Input per 1t FT fuels output. Product composition can be assumed to be 60% jet fuels/20% kerosene/20%LPG & fuel gases after upgrading, but we discard the LPG&fuel gas byproduct in this assumption – we’re focusing on the liquid products. Liquid products both have LHVs of 11.95 Mwh/t.",DEA technology data for Renewable fuels (2018): Hydrogen to Power.
ship loading,all,FT fuel,11.95,MWh_LHV,berth,1,t,0.083682008368201,Auxiliar process: converting between MWh_LHV and weight for shipping purposes. Converted assuming a product composition of 75% jet fuels/25% kerosene with a combined LHV of 11.95 MWh/t = (0.75*11.95+0.25*11.95)MWh/t.,n/a
ship unloading,all,berth,1,t,FT fuel,11.95,MWh_LHV,11.95,Auxiliar process: converting between MWh_LHV and weight for shipping purposes. Converted assuming a product composition of 75% jet fuels/25% kerosene with a combined LHV of 11.95 MWh/t = (0.75*11.95+0.25*11.95)MWh/t.,n/a
FT fuel storing and unstoring,all,FT fuel,9.799,MWh_LHV,FT fuel storage,1,m^3,0.102051229717318,"Storage units are usually per m^3, component for unit conversion. Based on FT fuel composition of 75% jet fuel/25% kerosene and a resulting density of 0.820 t/m^3 = (0.75*0.820 + 0.25*0.821)t/m^3 and LHV of 11.95 MWh/t = (0.75*11.95+0.25*11.95)MWh/t",
Ammonia cracker,all,ammonia (g),3191,MWh_LHV,hydrogen (g),2186,MWh_LHV,0.685051707928549,Assuming a integrated 200t/d cracking and purification facility. Electricity demand (316 MWh per 2186 MWh_LHV H2 output) is assumed to also be ammonia LHV input which seems a fair assumption as the facility has options for a higher degree of integration according to the report).,"ENGIE et al (2020): Ammonia to Green Hydrogen Feasibility Study (https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/880826/HS420_-_Ecuity_-_Ammonia_to_Green_Hydrogen.pdf), Fig. 10."
Steam methane reforming,all,methane (g),123.61032,MWh_LHV,hydrogen (g),83.33325,MWh_LHV,0.674160943843524,"Large scale SMR plant producing 2.5 kg/s H2 output (assuming 33.3333 MWh/t H2 LHV), with 6.9 kg/s CH4 input (feedstock) and 2 kg/s CH4 input (energy). Neglecting water consumption.","Keipi et al (2018): 10.1016/j.enconman.2017.12.063 , table 2."
Methanol steam reforming,all,methanol,40.0333,MWh_LHV,hydrogen (g),33.3333,MWh_LHV,0.83263932775964,Assuming per 1 t_H2 (with LHV 33.3333 MWh/t): 4.5 MWh_th and 3.2 MWh_el are required. We assume electricity can be substituted / provided with 1:1 as heat energy.,"Niermann et al (2021): 10.1016/j.rser.2020.110171 , table 4."
CCGT,all,hydrogen (g),1,MWh_LHV,electricity,0.58,MWh_el,0.58,,DEA technology data for electricity generation and district heating.
csp-tower power block,all,csp-tower bus,1,MWh,electricity,0.412,Mwh_el,0.412,Based on the default steam turbine used in the standard CSP tower setup in SAM. Thermal cycle efficiency only.,System Advisor Model (v2021.12.2) by NREL.