> ## 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.
# S3. Category 3: Fuel and Energy-Related Activities
> Learn how Dcycle automatically calculates upstream emissions from fuels and electricity not included in Scope 1 or 2
## Understanding Scope 3 Category 3
**Fuel and energy-related activities** (not included in Scope 1 or 2) cover the upstream emissions associated with the production and delivery of fuels and electricity consumed by your organization. According to the [GHG Protocol Scope 3 Standard](https://ghgprotocol.org/sites/default/files/2022-12/Chapter3.pdf), Category 3 includes:
* **Upstream emissions of purchased fuels**: Extraction, refining, and transportation of fuels (Well-to-Tank / WTT)
* **Upstream emissions of purchased electricity**: Extraction, refining, and transportation of fuels used in electricity generation
* **Transmission and distribution (T\&D) losses**: Energy lost in the grid during transmission
* **Generation of purchased electricity**: Emissions from power plants (when using market-based method)
```
┌─────────────────────────────────────────────────────────────────────────────┐
│ SCOPE 3 CATEGORY 3: Fuel & Energy-Related Activities │
├─────────────────────────────────────────────────────────────────────────────┤
│ │
│ YOUR SCOPE 1 & 2 EMISSIONS CATEGORY 3 (UPSTREAM) │
│ ──────────────────────── ────────────────────── │
│ │
│ ┌─────────────────────┐ ┌─────────────────────┐ │
│ │ Scope 1: Stationary │ ◄──────────────── │ WTT: Fuel │ │
│ │ (Boilers, heaters) │ Fuel burned │ extraction & │ │
│ │ │ │ refining │ │
│ └─────────────────────┘ └─────────────────────┘ │
│ │
│ ┌─────────────────────┐ ┌─────────────────────┐ │
│ │ Scope 1: Mobile │ ◄──────────────── │ WTT: Fuel │ │
│ │ (Vehicles, fleet) │ Fuel burned │ production & │ │
│ │ │ │ transport │ │
│ └─────────────────────┘ └─────────────────────┘ │
│ │
│ ┌─────────────────────┐ ┌─────────────────────┐ │
│ │ Scope 2: Electricity│ ◄──────────────── │ Grid T&D losses + │ │
│ │ (Grid power) │ Power consumed │ Upstream generation │ │
│ │ │ │ │ │
│ └─────────────────────┘ └─────────────────────┘ │
│ │
└─────────────────────────────────────────────────────────────────────────────┘
```
**Automatic Calculation**
**Category 3 emissions are automatically calculated by Dcycle.** You don't need to upload any additional data—simply ensure your Scope 1 and Scope 2 data is complete, and Category 3 will be calculated automatically.
This guide explains:
* What Category 3 includes
* How Dcycle calculates it
* How to view Category 3 emissions in reports
## How Category 3 Works in Dcycle
When you upload Scope 1 or Scope 2 data, Dcycle automatically calculates the corresponding Category 3 emissions:
| Your Input (Scope 1/2) | Dcycle Calculates (Category 3) |
| ------------------------- | --------------------------------------------------------- |
| Fuel invoice (stationary) | `stationary_generation` - WTT emissions |
| Vehicle consumption | `transport_generation` - WTT emissions |
| Electricity invoice | `electricity_generation` - Upstream generation |
| Electricity invoice | `electricity_transmission_and_distribution` - T\&D losses |
```
┌─────────────────────────────────────────────────────────────────────────────┐
│ AUTOMATIC CATEGORY 3 CALCULATION │
├─────────────────────────────────────────────────────────────────────────────┤
│ │
│ STEP 1: You upload data STEP 2: Dcycle calculates automatically │
│ ───────────────────────── ─────────────────────────────────────── │
│ │
│ POST /invoices ┌─────────────────────────────────┐ │
│ { │ Scope 1: Stationary combustion │ │
│ "type": "heat", ───────►│ + Category 3: WTT emissions │ │
│ "quantity": 5000, └─────────────────────────────────┘ │
│ "facility_fuel_id": "..." │
│ } │
│ │
│ POST /vehicle_consumptions ┌─────────────────────────────────┐ │
│ { │ Scope 1: Mobile combustion │ │
│ "quantity": 500, ───────►│ + Category 3: WTT emissions │ │
│ "vehicle_id": "..." └─────────────────────────────────┘ │
│ } │
│ │
│ POST /invoices ┌─────────────────────────────────┐ │
│ { │ Scope 2: Electricity │ │
│ "type": "electricity", ───────►│ + Category 3: T&D losses │ │
│ "quantity": 10000, │ + Category 3: Upstream gen │ │
│ "unit_id": "kwh-uuid" └─────────────────────────────────┘ │
│ } │
│ │
└─────────────────────────────────────────────────────────────────────────────┘
```
## Category 3 Sub-Categories
### 3a. Upstream Emissions of Purchased Fuels (WTT)
**Well-to-Tank (WTT)** emissions cover the full upstream lifecycle of fuels before combustion:
* Extraction of raw materials (crude oil, natural gas, coal)
* Refining and processing
* Transportation to point of sale
When you upload a **fuel invoice** for stationary combustion (boilers, heaters, generators), Dcycle automatically calculates:
* **Scope 1**: Direct emissions from burning the fuel (Tank-to-Wheel / TTW)
* **Category 3**: Upstream emissions from fuel production (Well-to-Tank / WTT)
```
Natural Gas Example:
─────────────────────────────────────────────────────────────────
Your invoice: 5,000 m³ natural gas
Scope 1 (TTW): 5,000 m³ × 2.0 kg CO₂e/m³ = 10,000 kg CO₂e
Category 3 (WTT): 5,000 m³ × 0.4 kg CO₂e/m³ = 2,000 kg CO₂e
─────────────────────────────────────────────────────────────────
Total lifecycle: = 12,000 kg CO₂e
```
**Dcycle category:** `stationary_generation`
When you upload a **vehicle consumption** record, Dcycle automatically calculates:
* **Scope 1**: Direct emissions from burning fuel in vehicle (TTW)
* **Category 3**: Upstream emissions from fuel production (WTT)
```
Diesel Vehicle Example:
─────────────────────────────────────────────────────────────────
Your consumption: 500 liters diesel
Scope 1 (TTW): 500 L × 2.68 kg CO₂e/L = 1,340 kg CO₂e
Category 3 (WTT): 500 L × 0.61 kg CO₂e/L = 305 kg CO₂e
─────────────────────────────────────────────────────────────────
Total lifecycle: = 1,645 kg CO₂e
```
**Dcycle category:** `transport_generation`
For Well-to-Tank (WTT) emissions, Dcycle uses emission factors from:
**DEFRA (UK Department for Environment, Food & Rural Affairs):**
* Comprehensive WTT factors for all fuel types
* Covers extraction, refining, and transportation of fuels
* Updated annually with UK Government GHG Conversion Factors
* Source: [UK Government GHG Conversion Factors](https://www.gov.uk/government/collections/government-conversion-factors-for-company-reporting)
Factors are automatically selected based on:
* Fuel type (natural gas, diesel, petrol, LPG, etc.)
* Year of consumption
WTT emissions are calculated as:
**WTT CO₂e = Fuel Quantity × WTT Emission Factor**
Where:
* **Fuel Quantity**: Amount of fuel consumed (liters, m³, kg, kWh)
* **WTT EF**: Well-to-Tank emission factor (kg CO₂e/unit)
WTT factors typically represent 15-25% of total lifecycle emissions for most fuels:
| Fuel Type | TTW (Scope 1) | WTT (Category 3) | WTT as % of Total |
| ----------- | ------------- | ---------------- | ----------------- |
| Natural Gas | \~0.18 kg/kWh | \~0.03 kg/kWh | \~14% |
| Diesel | \~2.5 kg/L | \~0.6 kg/L | \~19% |
| Petrol | \~2.2 kg/L | \~0.5 kg/L | \~19% |
| LPG | \~1.6 kg/L | \~0.3 kg/L | \~16% |
\*Note: Actual values vary by country and year.
### 3b. Upstream Emissions of Purchased Electricity
When you upload an **electricity invoice**, Dcycle calculates upstream emissions from electricity generation:
```
Electricity Example:
─────────────────────────────────────────────────────────────────
Your invoice: 10,000 kWh electricity (Spain, 2024)
Scope 2 (Location-based): 10,000 kWh × 0.10 kg/kWh = 1,000 kg CO₂e
Category 3 (Upstream gen): 10,000 kWh × 0.02 kg/kWh = 200 kg CO₂e
─────────────────────────────────────────────────────────────────
```
**Dcycle category:** `electricity_generation`
For upstream electricity generation, Dcycle uses:
* **Grid emission factors** adjusted for upstream fuel production
* Factors account for the fuel mix used in electricity generation
* Regional/national grid averages
The upstream generation factor represents emissions from:
* Extraction and processing of fuels used in power plants
* Transportation of fuels to power plants
* Construction and maintenance of generation infrastructure
### 3c. Transmission and Distribution (T\&D) Losses
Grid electricity is lost during transmission and distribution. Dcycle calculates emissions associated with generating this lost electricity:
```
T&D Losses Example:
─────────────────────────────────────────────────────────────────
Your invoice: 10,000 kWh electricity delivered
T&D Loss Rate (Spain): ~5%
Electricity lost in grid: 10,000 × 5% = 500 kWh
Category 3 (T&D losses): 500 kWh × 0.10 kg/kWh = 50 kg CO₂e
─────────────────────────────────────────────────────────────────
```
**Dcycle category:** `electricity_transmission_and_distribution`
Transmission and distribution loss rates vary by country:
| Country | Typical T\&D Loss Rate |
| ------------ | ---------------------- |
| Spain | \~5% |
| Germany | \~4% |
| France | \~6% |
| UK | \~8% |
| US (average) | \~5% |
Dcycle uses country-specific T\&D loss rates from:
* IEA (International Energy Agency) statistics
## Prerequisites for Category 3
Since Category 3 is automatically calculated, you simply need to ensure complete Scope 1 and Scope 2 data:
Upload all fuel consumption records:
* Stationary combustion invoices (boilers, heaters, generators)
* Vehicle consumption records (company fleet)
[See Step 2: Scope 1 Guide →](/guides/emissions/ghg-protocol-step-2-scope-1)
Upload all electricity consumption records:
* Electricity invoices for all facilities
* District heating/cooling (if applicable)
[See Step 3: Scope 2 Guide →](/guides/emissions/ghg-protocol-step-3-scope-2)
Dcycle automatically calculates Category 3 based on your Scope 1 and Scope 2 data.
No additional action required!
**Ensure Complete Coverage**
Category 3 emissions are only calculated for data you upload. To get accurate Category 3 totals:
* Include all fuel types across all facilities
* Cover all vehicles in your fleet
* Upload electricity for all locations
Missing Scope 1/2 data = Missing Category 3 data
## Viewing Category 3 Emissions
### Query Category 3 by Sub-Category
```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"),
}
# Query total impacts filtered by Category 3 categories
category_3_categories = [
"stationary_generation", # WTT from stationary fuels
"transport_generation", # WTT from mobile fuels
"electricity_generation", # Upstream electricity
"electricity_transmission_and_distribution", # T&D losses
]
response = requests.get(
"https://api.dcycle.io/v1/total_impacts",
headers=headers,
params={
"start_date": "2024-01-01",
"end_date": "2024-12-31",
"categories": ",".join(category_3_categories),
},
).json()
# Aggregate by sub-category
from collections import defaultdict
by_category = defaultdict(float)
for impact in response.get("items", []):
by_category[impact["category"]] += impact["emissions_per_day"]
print("📊 Scope 3 Category 3: Fuel & Energy-Related Activities")
print("=" * 60)
total = 0
for category, co2e in by_category.items():
label = {
"stationary_generation": "3a. WTT - Stationary Fuels",
"transport_generation": "3a. WTT - Mobile Fuels",
"electricity_generation": "3b. Upstream Electricity",
"electricity_transmission_and_distribution": "3c. T&D Losses",
}.get(category, category)
print(f" {label}: {co2e:,.0f} kg CO₂e")
total += co2e
print("=" * 60)
print(f" Total Category 3: {total:,.0f} kg CO₂e")
```
### Compare Category 3 to Scope 1 and 2
```python theme={"theme":{"light":"github-light","dark":"github-dark"}}
# Get Scope 1 emissions
scope1_response = requests.get(
"https://api.dcycle.io/v1/total_impacts",
headers=headers,
params={
"start_date": "2024-01-01",
"end_date": "2024-12-31",
"categories": "stationary,transport,recharge",
},
).json()
scope1_total = sum(i["emissions_per_day"] for i in scope1_response.get("items", []))
# Get Scope 2 emissions
scope2_response = requests.get(
"https://api.dcycle.io/v1/total_impacts",
headers=headers,
params={
"start_date": "2024-01-01",
"end_date": "2024-12-31",
"categories": "electricity",
},
).json()
scope2_total = sum(i["emissions_per_day"] for i in scope2_response.get("items", []))
# Category 3 total (from previous query)
cat3_total = total
print("\n📊 Emissions Comparison")
print("=" * 60)
print(f" Scope 1 (Direct): {scope1_total:>15,.0f} kg CO₂e")
print(f" Scope 2 (Electricity): {scope2_total:>15,.0f} kg CO₂e")
print(f" Category 3 (Upstream): {cat3_total:>15,.0f} kg CO₂e")
print("=" * 60)
# Calculate Category 3 as percentage of Scope 1+2
if (scope1_total + scope2_total) > 0:
cat3_pct = cat3_total / (scope1_total + scope2_total) * 100
print(f" Category 3 as % of Scope 1+2: {cat3_pct:.1f}%")
```
**Typical Category 3 Ratios**
Category 3 typically represents 15-25% of combined Scope 1 and Scope 2 emissions:
* **WTT emissions**: \~15-20% of Scope 1
* **Electricity upstream + T\&D**: \~5-10% of Scope 2
If your Category 3 is significantly different, check that all Scope 1/2 data is uploaded.
## Emission Factor Details
### WTT Factors by Fuel Type
| Fuel | Unit | TTW (Scope 1) | WTT (Cat 3) | WTT % |
| ----------------- | ----------- | ------------- | ----------- | ----- |
| Natural Gas | kg CO₂e/kWh | \~0.18 | \~0.03 | \~14% |
| Diesel / Gas Oil | kg CO₂e/L | \~2.5 | \~0.6 | \~19% |
| Petrol / Gasoline | kg CO₂e/L | \~2.2 | \~0.5 | \~19% |
| LPG | kg CO₂e/L | \~1.6 | \~0.3 | \~16% |
| Fuel Oil | kg CO₂e/L | \~2.9 | \~0.5 | \~15% |
\*Values are indicative. Actual factors vary by country and year.
### Electricity Factors (Spain Example)
| Component | Typical Value (2024) |
| ------------------- | -------------------- |
| Scope 2 Grid EF | \~0.10 kg CO₂e/kWh |
| Category 3 Upstream | \~0.02 kg CO₂e/kWh |
| T\&D Loss Rate | \~5% |
| Category 3 T\&D | \~0.005 kg CO₂e/kWh |
Dcycle updates Category 3 emission factors:
* **DEFRA WTT factors**: Updated annually when UK Government publishes new GHG Conversion Factors
* **Grid factors**: Updated with each new Ecoinvent release or regulatory update
* **T\&D loss rates**: Updated based on national grid operator data
When factors are updated, you can recalculate historical data to apply new factors.
## Best Practices
### 1. Ensure Complete Scope 1/2 Coverage
Category 3 is only as complete as your Scope 1 and Scope 2 data:
```python theme={"theme":{"light":"github-light","dark":"github-dark"}}
# Check for gaps in data coverage
def check_category_3_coverage(org_id, year):
"""Verify that Category 3 data is complete."""
# Get all facilities
facilities = requests.get(
"https://api.dcycle.io/v1/facilities",
headers=headers,
).json()
# Get all vehicles
vehicles = requests.get(
"https://api.dcycle.io/v1/vehicles",
headers=headers,
).json()
coverage_issues = []
# Check each facility has fuel/electricity data
for facility in facilities.get("items", []):
# Check for invoices
invoices = requests.get(
f"https://api.dcycle.io/v1/invoices",
headers=headers,
params={
"facility_id": facility["id"],
"start_date": f"{year}-01-01",
"end_date": f"{year}-12-31",
},
).json()
if not invoices.get("items"):
coverage_issues.append(
f"⚠️ Facility '{facility['name']}' has no invoices for {year}"
)
# Check each vehicle has consumption data
for vehicle in vehicles.get("items", []):
consumptions = requests.get(
f"https://api.dcycle.io/v1/vehicle_consumptions",
headers=headers,
params={
"vehicle_id": vehicle["id"],
"start_date": f"{year}-01-01",
"end_date": f"{year}-12-31",
},
).json()
if not consumptions.get("items"):
coverage_issues.append(
f"⚠️ Vehicle '{vehicle['name']}' has no consumptions for {year}"
)
return coverage_issues
```
### 2. Use Dcycle Reports for Category 3
Category 3 is automatically included in Dcycle's GHG reports:
* **ISO 14064 Report**: Category 3 mapped to appropriate sub-categories
* **GHG Protocol Report**: Separate Category 3 line items
* **ESG Reports**: Included in Scope 3 totals
### 3. Track Category 3 Trends
Monitor Category 3 over time to validate data quality:
```python theme={"theme":{"light":"github-light","dark":"github-dark"}}
# Compare Category 3 as % of Scope 1+2 across years
for year in [2022, 2023, 2024]:
# Get totals for each year
scope1_2 = get_scope_1_2_total(year)
cat3 = get_category_3_total(year)
ratio = cat3 / scope1_2 * 100 if scope1_2 > 0 else 0
print(f"{year}: Category 3 = {ratio:.1f}% of Scope 1+2")
# Ratio should be relatively stable (15-25%)
# Large variations may indicate data gaps
```
## Troubleshooting
### Issue: Category 3 is Zero or Missing
```python theme={"theme":{"light":"github-light","dark":"github-dark"}}
# Check if Category 3 is being calculated
cat3_total = get_category_3_total(2024)
if cat3_total == 0:
print("⚠️ Category 3 is zero. Possible causes:")
print(" 1. No Scope 1 fuel data uploaded")
print(" 2. No Scope 2 electricity data uploaded")
print(" 3. Custom emission factors used (WTT not calculated)")
# Check for custom emission factors
# Custom EFs bypass automatic WTT calculation
```
### Issue: Custom Emission Factors and Category 3
**Custom Emission Factors**
When you use a **custom emission factor** for fuel or electricity, Dcycle does **not** automatically calculate Category 3 WTT emissions. This is because custom factors may already include lifecycle emissions.
If your custom factor is:
* **TTW only**: You should manually add Category 3 data
* **WTW (lifecycle)**: Category 3 is already included—don't double count
Check with your custom factor source to understand what's included.
### Issue: Category 3 Seems Too High/Low
```python theme={"theme":{"light":"github-light","dark":"github-dark"}}
# Verify ratio is within expected range
expected_range = (0.15, 0.25) # 15-25% of Scope 1+2
scope1_2 = get_scope_1_2_total(2024)
cat3 = get_category_3_total(2024)
ratio = cat3 / scope1_2 if scope1_2 > 0 else 0
if ratio < expected_range[0]:
print(f"⚠️ Category 3 ({ratio:.1%}) below typical range")
print(" Possible causes:")
print(" - Some fuels using custom EFs (no WTT calculated)")
print(" - Fuel types with low WTT factors")
elif ratio > expected_range[1]:
print(f"⚠️ Category 3 ({ratio:.1%}) above typical range")
print(" Possible causes:")
print(" - High proportion of electricity vs direct fuel")
print(" - Countries with high T&D losses")
```
## Next Steps
Complete your Scope 1 data for accurate Category 3
Complete your Scope 2 data for T\&D calculations
Track transportation of purchased goods
Back to all Scope 3 categories