HST software interfaces with the pvsamv1 module within the SAM SDK for all energy simulations. The following table defines the specific SAM input variables which are set by HST software:
| SAM Variable | Value | Description |
| 6par_aisc | User Defined (within User Defined Module) | Open circuit voltage temperature coefficient |
| 6par_area | User Defined (within User Defined Module) | Module area |
| 6par_bifacial_ground_clearance_height | User Defined (within User Defined Module) | Ground Clearance Height of Rack (used for bifacial model) |
| 6par_bifacial_ground_transmission factor | User Defined (within User Defined Module) | Percentage of Front-side module area allowing passage of light, including gaps between modules. |
| 6par_bifaciality | User Defined (within User Defined Module) | Ratio of backside cell efficiency to frontside cell efficiency |
| 6par_bvoc | User Defined (within User Defined Module) | Short circuit current temperature coefficient |
| 6par_celltech | User Defined (within User Defined Module) | Solar cell technology type |
| 6par_gpmp | User Defined (within User Defined Module) | Maximum power point temperature coefficient |
| 6par_imp | User Defined (within User Defined Module) | Maximum Power Point Current |
| 6par_isc | User Defined (within User Defined Module) | Maximum Short Circuit Current |
| 6par_is_bifacial | User Defined (within User Defined Module) | Toggle to specify if module is bifacial or not |
| 6par_mounting | Fixed = One Story Building Height or Less | Array mounting height |
| 6par_nser | User Defined (within User Defined Module) | Number of Cells in Series |
| 6par_standoff | Fixed = Ground or Rack Mounted | Standoff mode |
| 6par_tnoct | User Defined (within User Defined Module) | Nominal operating cell temperature |
| 6par_vmp | User Defined (within User Defined Module) | Maximum power point voltage |
| 6par_voc | User Defined (within User Defined Module) | Maximum Open Circuit Voltage |
| acwiring_loss | Set to 0 | All AC modeling simulated external to SAM simulation |
| ac_transmission_loss | Set to 0 | All AC modeling simulated external to SAM simulation |
| adjust:constant | Set to 0 | All AC modeling simulated external to SAM simulation |
| albedo | Default = 0.2 | Ground Albedo used only if this data is not included in hourly weather file |
| cec_a_ref | Fixed (from CEC Module Database per User Selection of Module) | Nonideality factor a |
| cec_adjust | Fixed (from CEC Module Database per User Selection of Module) | Temperature coefficient adjustment |
| cec_alpha_sc | Fixed (from CEC Module Database per User Selection of Module) | Short circuit current temperature coefficient |
| cec_area | Fixed (from CEC Module Database per User Selection of Module) | Module area |
| cec_array_cols | Fixed = 10 | Columns of modules in array. Note: This parameter is not used in the energy model since cec_heat_transfer is set to use modue dimensions instead of Array dimensions |
| cec_array_rows | Fixed = 1 | Rows of modules in array. Note: This parameter is not used in the energy model since cec_heat_transfer is set to use modue dimensions instead of Array dimensions |
| cec_backside_temp | Fixed = 20 | Module backside temperature. Note: This parameter is not used in the energy model since cec_mounting_config is set to Rack Mounted |
| cec_beta_oc | Fixed (from CEC Module Database per User Selection of Module) | Open circuit voltage temperature coefficient |
| cec_bifacial_ground_clearance_height | User Defined (within User Defined Module) | Ground Clearance Height of Rack (used for bifacial model) |
| cec_bifacial_ground_transmission factor | User Defined (within User Defined Module) | Percentage of Front-side module area allowing passage of light, including gaps between modules. |
| cec_bifaciality | User Defined (within User Defined Module) | Ratio of backside cell efficiency to frontside cell efficiency |
| cec_gamma_r | Fixed (from CEC Module Database per User Selection of Module) | Maximum power point temperature coefficient |
| cec_gap_spacing | Fixed = 0.05 | Module Gap Spacing Note: This parameter is not used in the energy model since cec_mounting_config is set to Rack Mounted |
| cec_heat_transfer | Fixed = Module Dimensions | Heat transfer dimensions |
| cec_height | Fixed = One Story building Height or Lower | Array mounting height |
| cec_is_bifacial | User Defined (within User Defined Module) | Toggle to specify if module is bifacial or not |
| cec_i_l_ref | Fixed (from CEC Module Database per User Selection of Module) | Light current |
| cec_i_mp_ref | Fixed (from CEC Module Database per User Selection of Module) | Maximum power point current |
| cec_i_o_ref | Fixed (from CEC Module Database per User Selection of Module) | Saturation current |
| cec_i_sc_ref | Fixed (from CEC Module Database per User Selection of Module) | Short circuit current |
| cec_module_length | User Defined | Module Length |
| cec_module_width | User Defined | Module Width |
| cec_mounting_config | Fixed = Rack Mounted | Mounting configuration |
| cec_mounting_orientation | Fixed = Structures Do Not Impede Flow Underneath | Mounting structure orientation |
| cec_n_s | Fixed (from CEC Module Database per User Selection of Module) | Number of cells in series |
| cec_r_s | Fixed (from CEC Module Database per User Selection of Module) | Series resistance |
| cec_r_sh_ref | Fixed (from CEC Module Database per User Selection of Module) | Shunt resistance |
| cec_standoff | Fixed = Ground or Rack Mounted | Standoff mode |
| cec_t_noct | Fixed (from CEC Module Database per User Selection of Module) | Nominal operating cell temperature |
| cec_temp_corr_mode | Fixed = Heat Transfer Method | Cell temperature model selection |
| cec_v_mp_ref | Fixed (from CEC Module Database per User Selection of Module) | Maximum power point voltage |
| cec_v_oc_ref | Fixed (from CEC Module Database per User Selection of Module) | Open circuit voltage |
| dc_adjust:constant | User Defined = Non-Ohmic DC Loss Input | DC Constant loss adjustment |
| dcoptimizer_loss | Fixed = 0 | DC power optimizer loss |
| inv_ds_eff | User Defined (within User Defined Inverter) | Weighted or Peak or Nominal Efficiency |
| inv_ds_paco | User Defined (within User Defined Inverter) | AC maximum power rating |
| inv_ds_pnt | User Defined (within User Defined Inverter) | AC power consumed by inverter at night |
| inv_ds_pso | User Defined (within User Defined Inverter) | DC power required to enable the inversion process |
| inv_ds_vdcmax | User Defined (within User Defined Inverter) | Maximum DC input operating voltage |
| inv_ds_vdco | User Defined (within User Defined Inverter) | DC input voltage for the rated AC power rating |
| inv_snl_c0 | Fixed (from CEC Inverter Database per User Selection of Inverter) | Curvature between AC power and DC power at ref |
| inv_snl_c1 | Fixed (from CEC Inverter Database per User Selection of Inverter) | Coefficient of Pdco variation with DC input voltage |
| inv_snl_c2 | Fixed (from CEC Inverter Database per User Selection of Inverter) | Coefficient of Pso variation with DC input voltage |
| inv_snl_c3 | Fixed (from CEC Inverter Database per User Selection of Inverter) | Coefficient of Co variation with DC input voltage |
| inv_snl_paco | Fixed (from CEC Inverter Database per User Selection of Inverter) | AC maximum power rating |
| inv_snl_pdco | Fixed (from CEC Inverter Database per User Selection of Inverter) | DC input power at which AC power rating is achieved |
| inv_snl_pnt | Fixed (from CEC Inverter Database per User Selection of Inverter) | AC power consumed by inverter at night |
| inv_snl_pso | Fixed (from CEC Inverter Database per User Selection of Inverter) | DC power required to enable the inversion process |
| inv_snl_vdcmax | Fixed (from CEC Inverter Database per User Selection of Inverter) | Maximum DC input operating voltage |
| inv_snl_vdco | Fixed (from CEC Inverter Database per User Selection of Inverter) | DC input voltage for the rated AC power rating |
| inverter_count | HST Calculated | Number of inverters |
| inverter_model | Fixed (CEC Model when CEC Inverter Selected or Datasheet Model when User Defined Inverter Data Entered) | Inverter model specifier |
| irrad_mode | User Defined | Irradiance input translation mode |
| module_model | Fixed (CEC Model when CEC Module Selected or 6 Parameter Model when User Defined Module Data Entered) | Photovoltaic module model specifier |
| modules_per_string | HST Calculated | Modules per string |
| mppt_hi_inverter | User Defined (if User Defined Inverter) / Fixed (if CEC Inverter) | Maximum inverter MPPT voltage window |
| mppt_low_inverter | User Defined (if User Defined Inverter) / Fixed (if CEC Inverter) | Minimum inverter MPPT voltage window |
| sky_model | Fixed = Perez | Diffuse sky model |
| solar_resource_file | User Defined | Weather file in TMY2, TMY3 |
| strings_in_parallel | HST Calculated | String in parallel |
| subarray1_azimuth | HST Calculated (if Optimized over Azimuth) Otherwise User Defined | Sub-array 1 Azimuth |
| subarray1_backtrack | User Defined | Sub-array 1 Backtracking enabled |
| subarray1_dcwiring_loss | HST Calculated = DC String + DC Feeder Wiring Losses | Sub-array 1 DC wiring loss |
| subarray1_diodeconn_loss | Fixed = 0 | Sub-array 1 DC diodes and connections loss |
| subarray1_gcr | HST Calculated (if Optimized over Row Spacing) Otherwise User Defined | Sub-array 1 Ground coverage ratio |
| subarray1_mismatch_loss | Fixed = 0 | Sub-array 1 DC mismatch loss |
| subarray1_mod_orient | User Defined (Landscape or Portrait) | Sub-array 1 Module orientation for self-shading |
| subarray1_nameplate_loss | Fixed = 0 | Sub-array 1 DC nameplate loss |
| subarray1_nmodx | HST Calculated | Sub-array 1 no. of modules along bottom for self-shading |
| subarray1_nmody | User Defined = Number of Modules Up per Rack | Sub-array 1 no. of modules along side for self-shading |
| subarray1_rotlim | User Defined | Sub-array 1 Tracker rotation limit |
| subarray1_shade_mode | Fixed = Non-Linear (if Crystaline) or Linear (if Thin Film) | Sub-array 1 shading mode (fixed tilt or 1x tracking) |
| subarray1_soiling | User Defined (Annual or Monthly) | Sub-array 1 Monthly soiling loss |
| subarray1_tilt | HST Calculated (if Optimized over Tilt) Otherwise User Defined | Sub-array 1 Tilt |
| subarray1_track_mode | User Defined (Fixed-Tilt or Tracking) | Sub-array 1 Tracking mode |
| subarray1_tracking_loss | Fixed = 0 | Sub-array 1 DC tracking error loss |
| subarray2_enable | Fixed = Disabled | Sub-array 2 Enable |
| subarray3_enable | Fixed = Disabled | Sub-array 3 Enable |
| subarray4_enable | Fixed = Disabled | Sub-array 4 Enable |
| system_capacity | HST Calculated = DC Nameplate Rating | DC Nameplate capacity |
| system_use_lifetime_output | User Defined (either 1st year or lifetime simulation) | PV lifetime simulation |
| transformer_load_loss | Set to 0 | All AC modeling simulated external to SAM simulation |
| transformer_no_load_loss | Set to 0 | All AC modeling simulated external to SAM simulation |
| use_wf_albedo | Set to Yes | Uses hourly Ground Albedo if included in weather file |