## Assume **Purpose:** Controls sales carryover behavior, particularly useful for bank tracking scenarios. **Syntax:** `assume [no|only recharge|continued] streamName during years startYear to endYear` **Available Streams:** domestic, import, export, sales, virgin, bank, equipment **Examples:** ``` qubectalk assume no domestic during year 2030 assume only recharge sales during years 2025 to onwards assume continued import assume only recharge bank during years 3 to onwards ``` **Behavior:** - `assume no` - Sets stream to 0 kg (zero all sales) - `assume only recharge` - Sales only cover recharge needs, no new equipment - `assume continued` - Continue from previous year (default behavior)

## Cap **Purpose:** Limits consumption to specified levels, optionally with displacement to alternative substances. **Syntax:** ``` qubectalk cap streamName to amount during years startYear to endYear cap streamName to amount displacing "substanceName"|stream during years startYear to endYear cap streamName to amount displacing by volume "substanceName"|stream during years startYear to endYear cap streamName to amount displacing by units "substanceName"|stream during years startYear to endYear ``` **Examples:** ``` qubectalk cap sales to 80% during years 2027 to 2030 cap domestic to 0 mt displacing "R-600a" during years 2031 to onwards cap import to 50% during years 2028 to 2032 cap newEquipment to 90% prior year displacing "SubB" during years 3 to onwards ```

## Change **Purpose:** Applies growth or decline rates to consumption over time. **Syntax:** `change streamName by percentage % / year during years startYear to endYear` **Examples:** ``` qubectalk change sales by 6% / year during years 2025 to 2030 change domestic by -3% / year during years 2031 to 2035 change import by 5% / year during years 2025 to onwards change newEquipment by +10% / year during years 3 to 8 ``` **Non-Negative Clamping:** Change operations prevent streams from going negative. When a change would result in a negative value (e.g., reducing a 5 kg stream by 10 kg), the stream is clamped to exactly 0. The actual amount removed (not the requested amount) is used for downstream calculations. **Units Tracking Behavior:** Change operations preserve the current tracking mode of the stream. If the stream is currently in units (equipment-based), the change will be applied in units. If the stream is in kg or mt (volume-based), the change will be applied in volume units. Change operations do not force a conversion between tracking modes. **New Equipment Note:** Because recharge and precharge are computed from prior-year equipment independent of this year's sales, a marginal `change` to `newEquipment` always maps to an equal delta in `sales`, in any unit — unlike `set`, no recharge/precharge adjustment is needed. Negative results are silently clamped to 0.

## Define **Purpose:** Creates variables for use in calculations and conditional statements. **Syntax:** `define variableName as value` **Examples:** ``` qubectalk define baseGrowthRate as 5 define phaseOutYear as 2030 define targetReduction as 80 ```

## Enable **Purpose:** Activates specific supply streams for a substance. **Syntax:** `enable streamName` **Available Streams:** domestic, import, export **Examples:** ``` qubectalk enable domestic enable import enable export ```

## Equals (GWP) **Purpose:** Defines the Global Warming Potential and energy consumption for a substance. **Syntax:** `equals gwpValue [tCO2e|kgCO2e] / [mt|kg|unit] [energyValue kwh / unit] [during ...]` **Examples:** ``` qubectalk equals 1430 tCO2e / mt equals 1430 kgCO2e / kg equals 675 kgCO2e / kg 100 kwh / unit equals 3 tCO2e / mt equals 1 kwh / unit during year 2021 equals 1430 kgCO2e / kg during years 2025 to 2030 ``` **Note:** Both tCO2e (tonnes) and kgCO2e (kilograms) CO2 equivalent units are supported for GWP values. Both GHG and energy intensities support optional `during` clauses, allowing intensities to change over time (for example, to model energy efficiency improvements or refrigerant substitution). When a `during` clause is provided, the intensity is only set for the specified year(s); in other years, the prior intensity value is retained.

## Floor **Purpose:** Sets minimum consumption levels to prevent unrealistic reductions. **Syntax:** ``` qubectalk floor streamName to amount during years startYear to endYear floor streamName to amount displacing "substanceName"|stream during years startYear to endYear floor streamName to amount displacing by volume "substanceName"|stream during years startYear to endYear floor streamName to amount displacing by units "substanceName"|stream during years startYear to endYear ``` **Examples:** ``` qubectalk floor sales to 10% during years 2030 to onwards floor domestic to 5 mt during years 2025 to 2035 floor import to 100 units displacing by units "R-600a" during years 2028 to 2032 floor newEquipment to 550 units displacing "SubB" during years 3 to onwards ``` Floor supports the same displacement types as Cap. See [Cap](#cap) for detailed explanation of displacement behavior. **Units Tracking Behavior:** Floor commands follow the same units tracking behavior as cap commands. When a percentage-based floor triggers (increases the stream value), it preserves units tracking from the last specified value if that value was in equipment units. If the floor does not trigger, tracking mode remains unchanged. For `newEquipment` specifically, a triggered floor adds the deficit to `sales` rather than removing an excess.

## Get **Purpose:** Retrieves values from streams for use in expressions and calculations. **Syntax:** ``` qubectalk get streamName get streamName as units get streamName of "substanceName" get streamName of "substanceName" as units get streamName N years ago get streamName N years ago as units get streamName N years ago of "substanceName" get streamName N years ago of "substanceName" as units ``` **Available Streams:** - `sales`, `virgin`, `domestic`, `import`, `export` - Sales and trade volumes - `equipment`, `priorEquipment`, `newEquipment`, `bank` - Equipment population - `age` - Weighted average equipment age (read-only, Advanced Editor only) **Indirect Access (Cross-substance):** The `of "substanceName"` option allows you to access stream values from other substances within the same application. This is useful for creating dependencies between substances. **Years-Ago Queries:** The `N years ago` syntax allows you to retrieve a stream value from N years before the current simulation year. This is particularly useful for modeling fixed retirement schedules based on equipment age. **Example:** ``` qubectalk get newEquipment 5 years ago as units ``` **Note:** Asking for a value before the simulation start (e.g., asking for 5 years ago when the simulation is in year 3) returns 0. **Examples:** ``` qubectalk # Direct stream access define currentNewEquipment as get newEquipment as units define equipmentAge as get age as years retire (get age as years) * 1 % each year # Age-dependent retirement example define retirementRate as get age as years retire retirementRate % each year during years 5 to onwards # Cross-substance access with indirect option define substanceADomestic as get domestic of "substance a" as kg set domestic to (get domestic of "substance a" as kg) * 1.5 during year 1 # Unit conversion with indirect access define substanceAInMT as get import of "substance a" as mt # Years-ago access for fixed retirement schedules retire (0.2 * (get newEquipment 9 years ago as units)) units / year retire (0.6 * (get newEquipment 10 years ago as units)) units / year retire (0.2 * (get newEquipment 11 years ago as units)) units / year ``` **Note:** The `age` stream is a computed value that tracks the weighted average age of equipment. It starts at 0 years for new equipment and increases annually. There is no dedicated widget for it in the Basic Editor, but it can still be typed as a formula (e.g. `(get age as years) * 1`) into a Basic Editor numeric field such as the retirement box.

## Initial Charge **Purpose:** Specifies the amount of substance in new equipment per unit. **Syntax:** `initial charge with amount unit / unit for streamName` **Examples:** ``` qubectalk initial charge with 0.15 kg / unit for domestic initial charge with 0.20 kg / unit for import initial charge with 1.5 kg / unit for domestic ```

## Recharge **Purpose:** Specifies servicing patterns for equipment including frequency and amount. By default, services existing (prior) equipment, but can target new equipment (precharge) using the `of` clause. **Syntax:** `recharge percentage % [of target] with amount unit / unit` **Targets:** `priorEquipment` (default) for servicing existing equipment, or `newEquipment` for precharge (servicing new equipment before sale). **Examples:** ``` qubectalk recharge 10% with 0.15 kg / unit recharge 10% of priorEquipment with 0.15 kg / unit recharge 3% of newEquipment with 1 kg / unit recharge 15% with 0.85 kg / unit during years 2025 to 2030 recharge 5% of priorEquipment with 1.0 kg / unit in all years ```

## Recover **Purpose:** Implements recycling programs that recover and reuse substances from equipment. **Syntax:** `recover percentage % with reuse_percentage % reuse [with induction_percentage % induction] [at stage] [displacing "substanceName"] during years startYear to endYear` **Examples:** ``` qubectalk recover 30% with 90% reuse during years 2027 to onwards recover 50% with 80% reuse with 100% induction during years 2030 to 2035 recover 25% with 100% reuse with 0% induction at eol during years 2028 to onwards recover 20% with 80% reuse with default induction at recharge during years 2026 to onwards recover 15% with 85% reuse displacing "HFC-134a" during years 2025 to onwards ```

## Replace **Purpose:** Substitutes one substance with another in new equipment over specified time periods. **Syntax:** `replace percentage % of streamName with "newSubstanceName" during years startYear to endYear` **Examples:** ``` qubectalk replace 50% of domestic with "R-600a" during years 2027 to 2030 replace 100% of sales with "HFC-32" during years 2025 to onwards ```

## Retire **Purpose:** Sets equipment retirement rates determining equipment lifespan. **Syntax:** `retire percentage % each year` **Examples:** ``` qubectalk retire 5% each year retire 7% each year during years 2025 to 2030 retire 10% each year ``` **Mean lifetime (Weibull) form:** `retire number year old mean weibull` applies a Weibull survival curve (shape 2) driven by a mean equipment lifetime in years. So, the hazard of retirement rises with equipment age. The number is the average years a unit remains in service (a 20-year mean gives hazards of 0.2% at age 1, 3.7% at age 10, and 7.4% at age 20). Kigali Sim derives equipment ages from simulated sales, so it is recommended to start the simulation before the substance entered service. Combining this form with `set priorEquipment` / `change priorEquipment` for the same substance anywhere in a scenario's stack, including across stanzas such as a default-stanza `set priorEquipment` and a Weibull retire in a policy, raises a validation error. This is suppressed by treating existing stock as a single cohort of typical age (`assuming new`). In the Basic Editor, choose "year old (mean life, Weibull)" from the retirement units dropdown and enter the mean lifetime as the value; `assuming new` is code editor only. See [Tutorial 15](/guide/tutorial_15.html) for a worked comparison against a flat rate. **Examples:** ``` qubectalk retire 20 year old mean weibull retire 12.5 years old mean weibull during years 2030 to onwards retire 20 year old mean weibull assuming new ``` **Exact-age form:** `retire number year old exact` retires 100% of a sales cohort in the year it turns that many years old. It is a shortcut for `retire (get newEquipment number years ago as units) units / year`, so it shares that lookup's behavior: ages come from simulated sales history, and a cohort sold before the simulation start counts as zero. Use it when the exact retirement age is known rather than a hazard rate or mean lifetime. It is recommended to only use one exact-age retire per cohort. Because ages come from sales the same way as the Weibull form, combining this form with `set priorEquipment` / `change priorEquipment` for the same substance anywhere in a scenario's stack raises a validation error. As with the Weibull form, the `assuming new` modifier suppresses this by treating existing stock as a single cohort assumed to have entered service when the simulation began, so it retires in full once the simulation reaches the given age. Combine with `with replacement` to maintain equipment population. In the Basic Editor, choose "year old (exact)" from the retirement units dropdown and enter the age as the value; `assuming new` is code editor only. See [Tutorial 15](/guide/tutorial_15.html) for the exact retirement schedule section. **Examples:** ``` qubectalk retire 5 year old exact retire 10 years old exact during years 2030 to onwards retire 5 year old exact with replacement retire 5 year old exact assuming new ```

## Set **Purpose:** Sets consumption volumes or equipment units for specific streams and time periods. **Syntax:** `set streamName to amount unit during year year` **Examples:** ``` qubectalk set domestic to 25 mt during year 2025 set import to 15000 units during year 2025 set priorEquipment to 1000000 units during year 2025 set newEquipment to 900 units during year 2025 ``` **New Equipment Note:** `newEquipment` (equipment added in the current year) is writable directly. Setting it in `unit`/`units` relies on the implicit-recharge behavior described under Recharge above; setting it in a mass unit (`kg`, `mt`, or `tCO2e`) adds this year's recharge and precharge volume on top of the target amount before applying it. A bare `%` target resolves against this year's already-computed `newEquipment` value. Any resulting negative value is silently clamped to 0.

## See Also - [QubecTalk Stanzas Reference](/guide/qubectalk_stanzas.html) - [QubecTalk Language Features Reference](/guide/qubectalk_language_features.html) - [Return to Guide Index](/guide)