New Technologies: Concentrating Solar Thermal (CST) and HighTempThermalStorage in REopt

[Bill-Becker]

New Technologies: Concentrating Solar Thermal (CST) and High Temperature Thermal Storage in REopt

Overview

This release adds support for Concentrating Solar Thermal (CST) and High Temperature Thermal Storage to REopt. These technologies expand REopt’s ability to model high-temperature thermal generation and storage, supporting decarbonization of process heat and advanced thermal management.

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High-Level Summary

• New Technology Types:

  • CST (Concentrating Solar Thermal): Models parabolic trough collector (PTC) solar thermal systems
  • HighTempThermalStorage: Models sensible heat storage that can serve high-temperature loads.

• Integration:

  • Both CST and HighTempThermalStorage can meet process heat, domestic hot water (DHW), space heating, and can charge/discharge to one another and to other loads, depending on user configuration. However, the main use-case for PTC CST is industrial process heat.

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Detailed Updates: Input Parameters

CST (Concentrating Solar Thermal)

The CST object supports several technology types (tech_type: "ptc", "lf", "mst", "swh_evactube", "swh_flatplate") and exposes the following input parameters (see also cst_defaults.json):

• min_kw / max_kw: Minimum and maximum system size (kW thermal)
• installed_cost_per_kw: Installed capital cost ($/kW thermal)
• om_cost_per_kw: Fixed annual operations & maintenance ($/kW thermal)
• macrs_option_years: MACRS depreciation schedule (years)
• macrs_bonus_fraction: MACRS bonus depreciation fraction (0-1)
• can_serve_dhw: Can serve domestic hot water loads (true/false)
• can_serve_space_heating: Can serve space heating loads (true/false)
• can_serve_process_heat: Can serve process heat loads (true/false)
• charge_storage_only: Restrict CST to only charge storage (true/false)
• inlet_temp_degF, outlet_temp_degF: Supply/return temperatures (°F)
• SSC_Inputs: (optional) Dictionary of SAM-specific parameters for advanced users

HighTempThermalStorage

The HighTempThermalStorage object supports the following parameters:

• min_kwh / max_kwh: Minimum and maximum storage size (kWh thermal)
• installed_cost_per_kwh: Installed capital cost ($/kWh thermal)
• self_discharge_rate: Fraction of storage lost per hour (e.g., 0.001 = 0.1%/hr)
• macrs_option_years: MACRS depreciation schedule (years)
• macrs_bonus_fraction: MACRS bonus depreciation fraction (0-1)
• total_itc_fraction: Tax credit fraction of installed cost (0-1)

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Use Cases Enabled

• Evaluate the economics and performance of CST and high-temp storage to supply industrial process heat.
• Optimize sizing and dispatch of thermal technologies for cost and emissions objectives.

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Notes and Recommendations

• Backward compatibility: These additions are non-breaking; existing electric and thermal load models are unaffected.
• Further info: See the User Manual, and REopt.jl documentation)