> ## Documentation Index
> Fetch the complete documentation index at: https://code.dcycle.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Category 1: Direct GHG Emissions

> Quantify direct greenhouse gas emissions from sources owned or controlled by your organization

## Understanding Direct GHG Emissions

**Category 1** under ISO 14064-1 covers direct GHG emissions from sources that are owned or controlled by your organization. These emissions occur from sources within your organizational boundary where you have operational or financial control.

```
┌─────────────────────────────────────────────────────────────────────────────────┐
│                    CATEGORY 1: DIRECT GHG EMISSIONS                             │
├─────────────────────────────────────────────────────────────────────────────────┤
│                                                                                 │
│  ┌─────────────────────┐  ┌─────────────────────┐  ┌─────────────────────────┐  │
│  │ STATIONARY          │  │ MOBILE              │  │ PROCESS &               │  │
│  │ COMBUSTION          │  │ COMBUSTION          │  │ FUGITIVE                │  │
│  ├─────────────────────┤  ├─────────────────────┤  ├─────────────────────────┤  │
│  │ • Boilers           │  │ • Company vehicles  │  │ • Industrial processes  │  │
│  │ • Furnaces          │  │ • Delivery trucks   │  │ • Chemical reactions    │  │
│  │ • Generators        │  │ • Forklifts         │  │ • Refrigerant leaks     │  │
│  │ • Heating systems   │  │ • Ships & aircraft  │  │ • Gas pipeline leaks    │  │
│  └─────────────────────┘  └─────────────────────┘  └─────────────────────────┘  │
│                                                                                 │
│                    All sources OWNED or CONTROLLED by your organization         │
│                                                                                 │
└─────────────────────────────────────────────────────────────────────────────────┘
```

<Note>
  **Direct Emission Formula**

  **Direct GHG Emissions = Fuel Consumed × Emission Factor × GWP**

  Where:

  * **Fuel Consumed**: Amount of fuel burned (liters, m³, kg)
  * **Emission Factor**: kg CO₂e per unit of fuel
  * **GWP**: Global Warming Potential (for non-CO₂ gases)
</Note>

## Prerequisites

Before starting, ensure you have:

* Dcycle API credentials ([get them here](/docs/quickstart#step-1-get-your-api-key))
* List of all fuel-consuming equipment and vehicles
* Fuel consumption records (invoices, meter readings, fuel cards)
* Refrigerant inventory and recharge records

<Tip>
  **Using the Dcycle App?**

  You can also track direct emissions through our web interface:

  * [Vehicles](https://app.dcycle.io/vehicles) - Register and track fleet vehicles
  * [Facilities](https://app.dcycle.io/facilities) - Configure stationary combustion sources
</Tip>

## Data Map: Category 1 Requirements

```
┌─────────────────────────────────────────────────────────────────────────────────────────┐
│                      CATEGORY 1 DATA REQUIREMENTS                                       │
├─────────────────────────────────────────────────────────────────────────────────────────┤
│                                                                                         │
│  ┌─────────────────────────────────────────────────────────────────────────────────┐   │
│  │ MOBILE COMBUSTION                                                               │   │
│  ├─────────────────────────────────────────────────────────────────────────────────┤   │
│  │                                                                                 │   │
│  │  Vehicle Registration      Fuel Consumption          Activity Period            │   │
│  │  ─────────────────────     ────────────────          ───────────────            │   │
│  │  • Vehicle name/ID         • Fuel type               • Start date               │   │
│  │  • License plate           • Quantity (liters)       • End date                 │   │
│  │  • Vehicle type            • Cost (optional)        • Reporting year           │   │
│  │  • Fuel type                                                                    │   │
│  │                                                                                 │   │
│  └─────────────────────────────────────────────────────────────────────────────────┘   │
│                                                                                         │
│  ┌─────────────────────────────────────────────────────────────────────────────────┐   │
│  │ STATIONARY COMBUSTION                                                           │   │
│  ├─────────────────────────────────────────────────────────────────────────────────┤   │
│  │                                                                                 │   │
│  │  Facility Info             Fuel Invoices             Equipment Details          │   │
│  │  ────────────────          ─────────────             ─────────────────          │   │
│  │  • Facility name           • Fuel type               • Boiler capacity          │   │
│  │  • Location/country        • Quantity consumed       • Generator rating         │   │
│  │  • Facility type           • Invoice period          • Furnace specifications   │   │
│  │                            • Supplier                                           │   │
│  │                                                                                 │   │
│  └─────────────────────────────────────────────────────────────────────────────────┘   │
│                                                                                         │
│  ┌─────────────────────────────────────────────────────────────────────────────────┐   │
│  │ FUGITIVE EMISSIONS                                                              │   │
│  ├─────────────────────────────────────────────────────────────────────────────────┤   │
│  │                                                                                 │   │
│  │  Equipment Inventory       Refrigerant Data          Leak Records               │   │
│  │  ───────────────────       ────────────────          ────────────               │   │
│  │  • Equipment type          • Refrigerant type        • Leak detection dates     │   │
│  │  • Equipment count         • Charge amount (kg)      • Quantities lost          │   │
│  │  • Location                • Recharge records        • Repair records           │   │
│  │                                                                                 │   │
│  └─────────────────────────────────────────────────────────────────────────────────┘   │
│                                                                                         │
└─────────────────────────────────────────────────────────────────────────────────────────┘
```

## Mobile Combustion

Track emissions from company-owned or controlled vehicles, including fleet cars, delivery trucks, forklifts, ships, and aircraft.

### Step 1: Register Vehicles

<Accordion title="📋 Data Map: Vehicle Registration">
  | Field            | Type   | Required | Description              | Example                           |
  | ---------------- | ------ | -------- | ------------------------ | --------------------------------- |
  | `name`           | string | ✅        | Vehicle identifier       | `"Delivery Van 001"`              |
  | `plate`          | string | ✅        | License plate number     | `"ABC-1234"`                      |
  | `vehicle_type`   | string | ✅        | Type of vehicle          | `"van"`, `"truck"`, `"car"`       |
  | `fuel_type`      | string | ✅        | Primary fuel type        | `"diesel"`, `"gasoline"`, `"lpg"` |
  | `ownership_type` | string | ✅        | Ownership status         | `"owned"`, `"leased"`             |
  | `year`           | number | ❌        | Vehicle manufacture year | `2022`                            |
  | `brand`          | string | ❌        | Vehicle brand            | `"Ford"`                          |
  | `model`          | string | ❌        | Vehicle model            | `"Transit"`                       |

  **Where to get this data:**

  * **Vehicle details**: Fleet management system, vehicle registration documents
  * **Fuel type**: Vehicle specifications, fuel cards
</Accordion>

<CodeGroup>
  ```python Python theme={"theme":{"light":"github-light","dark":"github-dark"}}
  import requests
  import os

  headers = {
      "Authorization": f"Bearer {os.getenv('DCYCLE_API_KEY')}",
      "Content-Type": "application/json",
      "x-organization-id": os.getenv("DCYCLE_ORG_ID"),
      "x-user-id": os.getenv("DCYCLE_USER_ID"),
  }

  # Register a company vehicle
  vehicle_data = {
      "name": "Delivery Van 001",
      "plate": "ABC-1234",
      "vehicle_type": "van",
      "fuel_type": "diesel",
      "ownership_type": "owned",
      "year": 2022,
      "brand": "Ford",
      "model": "Transit",
  }

  response = requests.post(
      "https://api.dcycle.io/v1/vehicles",
      headers=headers,
      json=vehicle_data,
  )

  vehicle = response.json()
  print(f"✅ Vehicle registered: {vehicle['id']}")
  print(f"   Name: {vehicle['name']}")
  print(f"   Fuel type: {vehicle['fuel_type']}")
  ```

  ```javascript JavaScript theme={"theme":{"light":"github-light","dark":"github-dark"}}
  const axios = require('axios');

  const headers = {
    Authorization: `Bearer ${process.env.DCYCLE_API_KEY}`,
    'Content-Type': 'application/json',
    'x-organization-id': process.env.DCYCLE_ORG_ID,
    'x-user-id': process.env.DCYCLE_USER_ID,
  };

  // Register a company vehicle
  const vehicleData = {
    name: 'Delivery Van 001',
    plate: 'ABC-1234',
    vehicle_type: 'van',
    fuel_type: 'diesel',
    ownership_type: 'owned',
    year: 2022,
    brand: 'Ford',
    model: 'Transit',
  };

  const response = await axios.post(
    'https://api.dcycle.io/v1/vehicles',
    vehicleData,
    { headers }
  );

  const vehicle = response.data;
  console.log(`✅ Vehicle registered: ${vehicle.id}`);
  console.log(`   Name: ${vehicle.name}`);
  console.log(`   Fuel type: ${vehicle.fuel_type}`);
  ```
</CodeGroup>

### Step 2: Record Fuel Consumption

<Accordion title="📋 Data Map: Fuel Consumption">
  | Field        | Type   | Required | Description                     | Example         |
  | ------------ | ------ | -------- | ------------------------------- | --------------- |
  | `vehicle_id` | UUID   | ✅        | Reference to registered vehicle | `"abc-123-..."` |
  | `fuel_type`  | string | ✅        | Type of fuel consumed           | `"diesel"`      |
  | `quantity`   | number | ✅        | Amount of fuel                  | `500`           |
  | `unit`       | string | ✅        | Unit of measurement             | `"liters"`      |
  | `start_date` | date   | ✅        | Period start                    | `"2024-01-01"`  |
  | `end_date`   | date   | ✅        | Period end                      | `"2024-01-31"`  |

  **Where to get this data:**

  * **Fuel quantity**: Fuel cards, receipts, fleet management systems
  * **Dates**: Reporting period aligned with ISO 14064-1 requirements
</Accordion>

<CodeGroup>
  ```python Python theme={"theme":{"light":"github-light","dark":"github-dark"}}
  # Record monthly fuel consumption for a vehicle
  consumption_data = {
      "vehicle_id": vehicle["id"],
      "fuel_type": "diesel",
      "quantity": 500,
      "unit": "liters",
      "start_date": "2024-01-01",
      "end_date": "2024-01-31",
  }

  response = requests.post(
      "https://api.dcycle.io/v1/vehicle-consumptions",
      headers=headers,
      json=consumption_data,
  )

  consumption = response.json()
  print(f"✅ Fuel consumption recorded: {consumption['id']}")
  print(f"   Fuel: {consumption['quantity']} {consumption['unit']} of {consumption['fuel_type']}")
  print(f"   CO₂e: {consumption['co2e']} kg")
  print(f"   ISO 14064-1 Category: 1 (Direct GHG emissions)")
  ```

  ```javascript JavaScript theme={"theme":{"light":"github-light","dark":"github-dark"}}
  // Record monthly fuel consumption for a vehicle
  const consumptionData = {
    vehicle_id: vehicle.id,
    fuel_type: 'diesel',
    quantity: 500,
    unit: 'liters',
    start_date: '2024-01-01',
    end_date: '2024-01-31',
  };

  const consumptionResponse = await axios.post(
    'https://api.dcycle.io/v1/vehicle-consumptions',
    consumptionData,
    { headers }
  );

  const consumption = consumptionResponse.data;
  console.log(`✅ Fuel consumption recorded: ${consumption.id}`);
  console.log(`   Fuel: ${consumption.quantity} ${consumption.unit} of ${consumption.fuel_type}`);
  console.log(`   CO₂e: ${consumption.co2e} kg`);
  console.log(`   ISO 14064-1 Category: 1 (Direct GHG emissions)`);
  ```
</CodeGroup>

<Tip>
  **Bulk Upload for Large Fleets**

  For organizations with many vehicles, use bulk upload via CSV:

  ```csv theme={"theme":{"light":"github-light","dark":"github-dark"}}
  vehicle_name,plate,fuel_type,quantity,unit,start_date,end_date
  Van 001,ABC-1234,diesel,500,liters,2024-01-01,2024-01-31
  Truck 002,XYZ-5678,diesel,1200,liters,2024-01-01,2024-01-31
  Car 003,DEF-9012,gasoline,150,liters,2024-01-01,2024-01-31
  ```
</Tip>

## Stationary Combustion

Track emissions from fuel combustion in stationary equipment like boilers, furnaces, and generators.

### Step 1: Configure Facility

<Accordion title="📋 Data Map: Facility Configuration">
  | Field           | Type   | Required | Description      | Example                                |
  | --------------- | ------ | -------- | ---------------- | -------------------------------------- |
  | `name`          | string | ✅        | Facility name    | `"Main Factory"`                       |
  | `country`       | string | ✅        | Country code     | `"ES"`                                 |
  | `facility_type` | string | ✅        | Type of facility | `"factory"`, `"office"`, `"warehouse"` |

  **Where to get this data:**

  * **Facility details**: Property records, lease agreements
</Accordion>

```python theme={"theme":{"light":"github-light","dark":"github-dark"}}
# Get your facilities
response = requests.get(
    "https://api.dcycle.io/v1/facilities",
    headers=headers,
).json()

print(f"📋 Your facilities:")
for facility in response["items"]:
    print(f"   - {facility['name']} ({facility['country']})")
    print(f"     ID: {facility['id']}")
```

### Step 2: Record Fuel Invoices

<Accordion title="📋 Data Map: Stationary Fuel Invoice">
  | Field         | Type   | Required | Description           | Example                              |
  | ------------- | ------ | -------- | --------------------- | ------------------------------------ |
  | `facility_id` | UUID   | ✅        | Reference to facility | `"abc-123-..."`                      |
  | `fuel_type`   | string | ✅        | Type of fuel          | `"natural_gas"`, `"diesel"`, `"lpg"` |
  | `quantity`    | number | ✅        | Amount consumed       | `5000`                               |
  | `unit`        | string | ✅        | Unit of measurement   | `"m3"`, `"kWh"`, `"liters"`          |
  | `start_date`  | date   | ✅        | Invoice period start  | `"2024-01-01"`                       |
  | `end_date`    | date   | ✅        | Invoice period end    | `"2024-01-31"`                       |

  **Where to get this data:**

  * **Fuel consumption**: Utility invoices, meter readings
  * **Supplier details**: Invoice headers, contracts
</Accordion>

<CodeGroup>
  ```python Python theme={"theme":{"light":"github-light","dark":"github-dark"}}
  # Record natural gas consumption for heating
  fuel_invoice = {
      "facility_id": "your-facility-uuid",
      "fuel_type": "natural_gas",
      "quantity": 5000,
      "unit": "m3",
      "start_date": "2024-01-01",
      "end_date": "2024-01-31",
  }

  response = requests.post(
      "https://api.dcycle.io/v1/invoices",
      headers=headers,
      json=fuel_invoice,
  )

  invoice = response.json()
  print(f"✅ Fuel invoice recorded: {invoice['id']}")
  print(f"   Natural gas: {invoice['quantity']} m³")
  print(f"   CO₂e: {invoice['co2e']} kg")
  print(f"   ISO 14064-1 Category: 1 (Direct GHG emissions)")
  ```

  ```javascript JavaScript theme={"theme":{"light":"github-light","dark":"github-dark"}}
  // Record natural gas consumption for heating
  const fuelInvoice = {
    facility_id: 'your-facility-uuid',
    fuel_type: 'natural_gas',
    quantity: 5000,
    unit: 'm3',
    start_date: '2024-01-01',
    end_date: '2024-01-31',
  };

  const invoiceResponse = await axios.post(
    'https://api.dcycle.io/v1/invoices',
    fuelInvoice,
    { headers }
  );

  const invoice = invoiceResponse.data;
  console.log(`✅ Fuel invoice recorded: ${invoice.id}`);
  console.log(`   Natural gas: ${invoice.quantity} m³`);
  console.log(`   CO₂e: ${invoice.co2e} kg`);
  console.log(`   ISO 14064-1 Category: 1 (Direct GHG emissions)`);
  ```
</CodeGroup>

## Process Emissions

Track emissions from industrial processes and chemical reactions (e.g., cement production, chemical manufacturing).

<Warning>
  **Industry-Specific Emissions**

  Process emissions vary significantly by industry:

  * **Cement**: Cite calcination of limestone
  * **Chemicals**: Chemical reactions producing GHGs
  * **Metals**: Reduction processes, electrode consumption

  Use Custom Emission Factors for accurate process emission calculations.
</Warning>

```python theme={"theme":{"light":"github-light","dark":"github-dark"}}
# Record process emissions using custom emission factors
process_emission = {
    "emission_group_id": "your-process-emission-group-id",
    "quantity": 10000,  # e.g., tonnes of cement produced
    "unit": "tonnes",
    "date": "2024-01-31",
    "description": "Cement clinker production",
}

response = requests.post(
    "https://api.dcycle.io/v1/custom-emissions",
    headers=headers,
    json=process_emission,
)

emission = response.json()
print(f"✅ Process emission recorded: {emission['id']}")
print(f"   CO₂e: {emission['co2e']} kg")
print(f"   ISO 14064-1 Category: 1 (Direct GHG emissions - Process)")
```

## Fugitive Emissions

Track emissions from unintentional releases, particularly refrigerant leaks from cooling equipment.

<Accordion title="📋 Data Map: Fugitive Emissions">
  | Field              | Type   | Required | Description             | Example                          |
  | ------------------ | ------ | -------- | ----------------------- | -------------------------------- |
  | `refrigerant_type` | string | ✅        | Refrigerant used        | `"R-134a"`, `"R-410A"`, `"R-22"` |
  | `quantity_lost`    | number | ✅        | Amount leaked/recharged | `5`                              |
  | `unit`             | string | ✅        | Unit of measurement     | `"kg"`                           |
  | `date`             | date   | ✅        | Date of leak/recharge   | `"2024-03-15"`                   |

  **Where to get this data:**

  * **Refrigerant data**: Service records, recharge invoices
</Accordion>

```python theme={"theme":{"light":"github-light","dark":"github-dark"}}
# Record refrigerant leak/recharge
fugitive_emission = {
    "emission_group_id": "refrigerant-emissions-group-id",
    "refrigerant_type": "R-134a",
    "quantity": 5,  # kg of refrigerant recharged
    "unit": "kg",
    "date": "2024-03-15",
    "description": "AC unit recharge - Building A",
}

response = requests.post(
    "https://api.dcycle.io/v1/custom-emissions",
    headers=headers,
    json=fugitive_emission,
)

emission = response.json()
print(f"✅ Fugitive emission recorded: {emission['id']}")
print(f"   Refrigerant: {fugitive_emission['quantity']} kg R-134a")
print(f"   CO₂e: {emission['co2e']} kg")
print(f"   ISO 14064-1 Category: 1 (Direct GHG emissions - Fugitive)")
```

<Note>
  **Refrigerant GWP Values**

  Refrigerants have very high GWP values. Common refrigerants:

  | Refrigerant | GWP (100-year) |
  | ----------- | -------------- |
  | R-134a      | 1,530          |
  | R-410A      | 2,256          |
  | HFC-143     | 364            |

  Even small leaks can result in significant CO₂e emissions.
</Note>

## Query Category 1 Emissions

Retrieve all your direct emissions for reporting:

```python theme={"theme":{"light":"github-light","dark":"github-dark"}}
# Get Category 1 emissions summary
response = requests.get(
    f"https://api.dcycle.io/v1/organizations/{os.getenv('DCYCLE_ORG_ID')}/emissions",
    headers=headers,
    params={
        "year": 2024,
        "category": "direct",  # ISO 14064-1 Category 1
    },
).json()

print(f"📊 Category 1: Direct GHG Emissions (2024)")
print(f"")
print(f"   Mobile Combustion: {response['mobile_combustion']:,.0f} kg CO₂e")
print(f"   Stationary Combustion: {response['stationary_combustion']:,.0f} kg CO₂e")
print(f"   Process Emissions: {response['process']:,.0f} kg CO₂e")
print(f"   Fugitive Emissions: {response['fugitive']:,.0f} kg CO₂e")
print(f"   ─────────────────────────")
print(f"   TOTAL CATEGORY 1: {response['total']:,.0f} kg CO₂e")
```

## Emission Factors

### Stationary Combustion Calculation Methods by Country

Dcycle automatically applies the appropriate calculation methodology based on your facility's country:

<Tabs>
  <Tab title="Spain (MITECO)">
    For facilities located in **Spain**, Dcycle uses emission factors from **MITECO** (Ministerio para la Transición Ecológica y el Reto Demográfico).

    ```
    Facility (ES) → Invoice → MITECO Emission Factors → CO₂e
          ↓              ↓                ↓                ↓
      Country: ES    Fuel type     Spanish-specific    Compliant with
                     + quantity    factors by year     Spanish regulations
    ```

    **Key characteristics:**

    * Emission factors specific to Spain, updated annually
    * Fuel types mapped to MITECO categories (e.g., `natural_gas`, `gas_oil_b`, `lpg`)
    * Required for Spanish regulatory compliance (ISO 14064, EINF)
    * Includes factors for CO₂, CH₄, and N₂O

    <Tip>
      Access MITECO emission factors [here](https://share.google/W1lMiBNVV6qWyZxA5).
    </Tip>

    <AccordionGroup>
      <Accordion title="Emission Factor Sources - Spain (MITECO)">
        For Spanish facilities, Dcycle uses emission factors from:

        * **MITECO** (Ministerio para la Transición Ecológica y el Reto Demográfico)
        * Updated annually with Spanish-specific factors
        * Source: [Factores de emisión](https://share.google/W1lMiBNVV6qWyZxA5)

        Factors are automatically selected based on:

        * Fuel type (mapped to MITECO categories)
        * Unit of measurement
        * Invoice year
      </Accordion>

      <Accordion title="Calculation Details - Spain (MITECO)">
        For Spanish facilities, stationary combustion emissions are calculated as:

        **CO₂e = Fuel Quantity × (EF\_CO₂ × GWP\_CO₂ + EF\_CH₄ × GWP\_CH₄ + EF\_N₂O × GWP\_N₂O)**

        Where:

        * **Fuel Quantity**: Amount consumed (liters, m³, kg, kWh)
        * **EF\_XXX**: MITECO emission factor for the specific GHG gas (CO₂, CH₄, N₂O) and fuel, unit, and year
        * **GWP\_XXX**: Global Warming Potential for the specific GHG gas (CO₂, CH₄, N₂O) (IPCC AR6 GWP values)

        **Example (Natural Gas):**

        ```
        5,000 KWH × (0.182 kg CO₂/KWH x 1 + 0.000016 kg CH₄/KWH x 27.9 + 0.000000 kg N₂O/KWH x 273) = 912.23 kg CO₂e
        ```
      </Accordion>
    </AccordionGroup>
  </Tab>

  <Tab title="Other Countries (GHG Protocol)">
    For facilities in **any other country**, Dcycle uses emission factors from the [**IPCC/GHG Protocol** database](https://ghgprotocol.org/calculation-tools-and-guidance).

    ```
    Facility (non-ES) → Invoice → IPCC Emission Factors → CO₂e
          ↓                 ↓                ↓                ↓
      Country: XX       Fuel type     Global default      GHG Protocol
                        + quantity    factors (IPCC)      compliant
    ```

    **Key characteristics:**

    * IPCC-based emission factors (globally recognized)
    * Fuel types follow GHG Protocol naming conventions
    * Compatible with international reporting standards
    * Includes Net Calorific Value (NCV) calculations

    <Tip>
      Access GHG Protocol emission factors [here](https://ghgprotocol.org/sites/default/files/2024-10/Stationary_combustion_tool_Version4-2.xlsx).
    </Tip>

    <AccordionGroup>
      <Accordion title="Emission Factor Sources - Other Countries (GHG Protocol)">
        For non-Spanish facilities, Dcycle uses emission factors from:

        * **IPCC** (Intergovernmental Panel on Climate Change)
        * **GHG Protocol** Stationary Combustion Tool
        * Source: [GHG Protocol Calculation Tools](https://ghgprotocol.org/sites/default/files/2024-10/Stationary_combustion_tool_Version4-2.xlsx)

        Factors are automatically selected based on:

        * Fuel type (GHG Protocol naming conventions)
        * Net Calorific Value (NCV) of the fuel
        * Country-specific adjustments where available
      </Accordion>

      <Accordion title="Calculation Details - Other Countries (GHG Protocol)">
        For non-Spanish facilities, stationary combustion emissions follow the GHG Protocol methodology:

        **CO₂e = Fuel Quantity × Density × NCV × EF\_IPCC × GWP**

        Where:

        * **Fuel Quantity**: Amount consumed (converted to mass in Gg)
        * **Density**: Density of the fuel
        * **NCV**: Net Calorific Value (TJ/Gg) - energy content per unit mass
        * **EF\_IPCC**: IPCC emission factor (kg gas/TJ)
        * **GWP\_XXX**: Global Warming Potential for the specific GHG gas (CO₂, CH₄, N₂O) (IPCC AR6 GWP values)

        The calculation process:

        1. Convert fuel quantity to energy (TJ) using NCV
        2. Apply emission factors for CO₂, CH₄, and N₂O
        3. Convert each gas to CO₂e using GWP factors
        4. Sum all gases for total CO₂e

        **Example (Natural Gas):**

        ```
        Step 1: 5,000 m³ × 0.7 kg/m³ (density) *0.001 (to convert to Gg)→ mass in Gg
        Step 2: mass × 48.0 TJ/Gg (NCV) → energy in TJ
        Step 3: energy × 56,100 kg CO₂/TJ → CO₂ emissions
        Step 4: Add CH₄ and N₂O contributions and convert to CO₂e using GWP factors → total CO₂e
        ```
      </Accordion>
    </AccordionGroup>
  </Tab>
</Tabs>

<Note>
  **Automatic Method Selection**

  You don't need to specify which calculation method to use. Dcycle automatically detects the facility's country and applies the correct emission factors:

  * `country: "ES"` → MITECO factors
  * Any other country → GHG Protocol/IPCC factors
</Note>

### Mobile Combustion Emission Factors

<AccordionGroup>
  <Accordion title="Emission Factor Sources">
    Dcycle uses country-specific emission factors from:

    * **DEFRA** (UK Department for Environment, Food & Rural Affairs) *Coming soon!*
    * **MITECO** (Spanish Ministry for Ecological Transition)

    Factors are automatically selected based on vehicle country and fuel type.
  </Accordion>

  <Accordion title="Calculation Details">
    Mobile combustion emissions are calculated as:

    **CO₂e = Fuel Quantity × (EF\_CO₂ × GWP\_CO₂ + EF\_CH₄ × GWP\_CH₄ + EF\_N₂O × GWP\_N₂O)**

    Where emission factors (EF) are specific to:

    * Fuel type (diesel, petrol, LPG, etc.)
    * Vehicle type (passenger car, light truck, heavy truck)
    * Country (regional emission factors)
    * Unit (liters, kilometers, etc.)
  </Accordion>
</AccordionGroup>

### Fugitive Emission Factors

<AccordionGroup>
  <Accordion title="Refrigerant GWP Values">
    Dcycle uses GWP values from IPCC AR6 (2021) for refrigerants.

    Note: Core GHG gases use AR6 values: CO₂ = 1.00, CH₄ = 27.90, N₂O = 273.00
  </Accordion>

  <Accordion title="Calculation Details">
    Fugitive emissions from refrigerant leaks are calculated as:

    **CO₂e = Refrigerant Quantity × GWP**

    Where:

    * **Refrigerant Quantity**: Amount leaked or recharged (kg)
    * **GWP**: Global Warming Potential for the specific refrigerant (IPCC AR6 values)
  </Accordion>
</AccordionGroup>

## Best Practices

<Tip>
  **ISO 14064-1 Category 1 Best Practices**

  1. **Complete inventory**: Identify ALL direct emission sources before data collection
  2. **Consistent boundaries**: Apply same organizational boundary throughout
  3. **Activity data quality**: Use metered data when possible over estimates
  4. **Document assumptions**: Record any estimates or proxies used
  5. **Regular updates**: Track emissions monthly for better accuracy
</Tip>

## Next Steps

<CardGroup cols={2}>
  <Card title="Category 2: Imported Energy" icon="bolt" href="/guides/emissions/iso-14064-category-2-indirect-energy">
    Track emissions from purchased electricity, heat, and cooling
  </Card>

  <Card title="Back to ISO 14064 Tutorial" icon="arrow-left" href="/guides/emissions/iso-14064-tutorial">
    Return to the main ISO 14064 tutorial
  </Card>
</CardGroup>