Pricing fields to update. At least one field must be provided. flat_system_price, price_per_watt, and line_items are mutually exclusive — provide one solar pricing field, not more than one. line_items sets per-component solar prices and sets the solar pricing mode to price breakdown. storage_flat_system_price and storage_line_items are mutually exclusive. Either storage field can be provided alone or alongside a solar pricing field. heat_pump_flat_system_price and heat_pump_line_items are mutually exclusive. Either heat pump field can be provided alone or alongside a solar or storage pricing field.