| Notation | Description |
|---|
| $x_{z,t}^{\textrm{H,EMI}}$ | The amount of carbon dioxide emitted by the hydrogen supply chain at time $t$ in region $z$ |
| $x_{g,z,t}^{\textrm{H,GEN}}$ | this term represents hydrogen injected into the grid by hydrogen generation resource $g$ in zone $z$ at time period $t$ |
| $x_{g,z,t}^{\textrm{H,LIQ}}$ | this term represents liquefied hydrogen (gas to liquid) injected into the grid by hydrogen generation resource $g$ in zone $z$ at time period $t$ |
| $x_{g,z,t}^{\textrm{H,EVAP}}$ | this term represents evaporated hydrogen (liquid to gas) injected into the grid by hydrogen generation resource $g$ in zone $z$ at time period $t$ |
| $x_{s,z,t}^{\textrm{H,NSD}}$ | this term represents the total amount of hydrogen demand curtailed in demand segment $s$ at time period $t$ in zone $z$ |
| $x_{s,z,t}^{\textrm{H,DIS}}$ | this term represents hydrogen injected into the grid by hydrogen storage resource $s$ in zone $z$ at time period $t$ |
| $x_{s,z,t}^{\textrm{H,CHA}}$ | this term represents charged hydrogen into the storage device $s$ in zone $z$ at time period $t$ |
| $x_{k,z,t}^{\textrm{H,G2P}}$ | representing energy injected into the grid by hydrogen to power resource $k$ in zone $z$ at time period $t$ |
| $x_{z,t}^{\textrm{E,H-GEN}}$ | representing power consumed by electrolyzers in zone $z$ at time period $t$ |
| $x_{i,z \rightarrow z^{\prime},t}^{\textrm{H,PIP}}$ | the hydrogen pipeline flow decision variable representing hydrogen flow via pipeline of type $i$ through path $z \rightarrow z^{\prime}$ at time period $t$ |
| $y_{g,z}^{\textrm{H,GEN,existing}}$ | existing capacity of hydrogen generation resources in hydrogen sector |
| $y_{g,z}^{\textrm{H,GEN,new}}$ | the newly invested capacity of hydrogen generation resources in hydrogen sector |
| $y_{g,z}^{\textrm{H,GEN,retired}}$ | retired capacity of hydrogen generation resources in hydrogen sector |
| $y_{k,z}^{\textrm{H,G2P}}$ | this term is the total installed capacity of hydrogen to power plants |
| $y_{g}^{\textrm{H,G2P,total}}$ | existing capacity of hydrogen to power resources in hydrogen sector $y_{k,z}^{\textrm{H,G2P}} = y_{k,z}^{\textrm{H,G2P,total}}$ |
| $y_{g}^{\textrm{H,G2P,existing}}$ | existing capacity of hydrogen to power resources in hydrogen sector |
| $y_{g}^{\textrm{H,G2P,new}}$ | newly installed capacity of hydrogen to power resources in hydrogen sector |
| $y_{g}^{\textrm{H,G2P,retired}}$ | retired capacity of hydrogen to power resources in hydrogen sector |
| $y_{s,z}^{\textrm{H,STO,ENE}}$ | the installed energy storage capacity |
| $y_{s,z}^{\textrm{H,STO,POW}}$ | the installed power capacity |
| $y_{i,z \rightarrow z^{\prime}}^{\textrm{H,PIP}}$ | the hydrogen pipeline construction decision variable representing newly constructed hydrogen pipeline of type $i$ through path $z \rightarrow z^{\prime}$ |
| $n_{k,z,t}^{\textrm{H,G2P}}$ | the commitment state variable of generator cluster $k$ in zone $z$ at time $t$ |
| $n_{k,z,t}^{\textrm{H,G2P,UP}}$ | the number of startup decision variable of generator cluster $k$ in zone $z$ at time $t$ |
| $n_{k,z,t}^{\textrm{H,G2P,DN}}$ | the number of shutdown decision variable of generator cluster $k$ in zone $z$ at time $t$ |
| $\tau_{k,z}^{\textrm{H,UP}}$ and $\tau_{k,z}^{\textrm{H,DN}}$ | is the minimum up or down time for units in generating cluster $k$ in zone $z$ |
| $\epsilon_{z,p,load}^{maxCO_2}$ | denotes the emission limit in terms on tonne-CO$_2$/MWh |
| $U_{s,z,t}^{\textrm{H,STO}}$ | this term represents initial hydrogen stored in the storage device $s$ in zone $z$ at all starting time period $t$ of modeled periods |
| $\Delta U_{s,z,m}^{\textrm{H,STO}}$ | this term represents the change of storage hydrogen inventory level of the storage device $s$ in zone $z$ during each representative period $m$ |
| $U_{i,z \rightarrow z^{\prime},t}^{\textrm{H,PIP}}$ | the hydrogen pipeline storage level decision variable representing hydrogen stored in pipeline of type $i$ through path $z \rightarrow z^{\prime}$ at time period $t$ |
| $v_{CAP,j}^{\textrm{H,TRU}}$ | the total number of carbon capture of existing truck ??this may be is a error ,should let H truck replace CAP truck. |
| $v_{RETCAP,j}^{\textrm{H,TRU}}$ | the total number of carbon capture of Truck retirements |
| $v_{NEWCAP,j}^{\textrm{H,TRU}}$ | the total number of carbon capture of newly add Truck |
| Notation | Description |
|---|
| $\textrm{c}_{z}^{\textrm{H,EMI}}$ | Cost of per ton carbon dioxide emitted in the hydrogen supply chain |
| $\textrm{c}_{g}^{\textrm{H,INV}}$ | equipment investment cost per ton of hydrogen production capacity |
| $\textrm{c}_{g}^{\textrm{H,FOM}}$ | fixed operation cost in hydrogen supply chain for hydrogen generationa nd storage devices |
| $\textrm{c}^{\textrm{H,GEN,c}}$ | additional investment costs of hydrogen production |
| $\textrm{n}_{s}^{\textrm{H,NSD}}$ | this term represents the marginal willingness to pay for hydrogen demand of this segment of demand |
| $\textrm{D}_{z, t}^{\textrm{H}}$ | hydrogen demand in zone $z$ at time $t$ |
| $\textrm{C}^{\textrm{H,GEN,o}}$ | total generation cost for per tonne of hydrogen from hydrogen generation plants |
| $\textrm{c}_{g}^{\textrm{H,FUEL}}$ | fuel cost for hydrogen generation plants |
| $\textrm{c}_{g}^{\textrm{H,VOM}}$ | variable cost for hydrogen generation plants |
| $\overline{y}_{g}^{\textrm{\textrm{H,G2P}}}$ | upper bound of capacity is defined,then we impose constraints on maximum power capacity |
| $\underline{y}_{g}^{\textrm{\textrm{H,G2P}}}$ | lower bound of capacity is defined,then we impose constraints on minimum power capacity |
| $\eta_{s,z}^{\textrm{H,loss}}$ | the self discharge rate for the storage resource |
| $\rho^{max}_{y,z,t}$ | the availability factor for Bounds on available demand flexibility |
| $\Omega_{k,z}^{\textrm{H,G2P,size}}$ | is the unit size |
| $\epsilon_{y,z}^{CO_2}$ | the parameter reflects the specific CO$_2$ emission intensity in tonne-CO$_2$/MWh associated with its operation |
| $\rho_{y,z,t}^{max}$ | maximum deferrable demand as a fraction of available capacity in a particular time step $t$ |
| $\tau_{y,z}^{advance/delay}$ | the maximum time this demand can be advanced and delayed, defined by parameters, $\tau_{y,z}^{advance}$ and $\tau_{y,z}^{delay}$,respectively |
| $\eta_{y,z}^{dflex}$ | the energy losses associated with shifting demand |
| $\overline{\textrm{R}}_{s,z}^{\textrm{H,CHA}}$ | For storage resources where upper bound is defined, then we impose constraints on minimum and maximum storage charge capacity |
| $\underline{\textrm{R}}_{s,z}^{\textrm{H,CHA}}$ | For storage resources where lower bound is defined, then we impose constraints on minimum and maximum storage charge capacity |