# WAPP ASB0034-2021 Grid Emission Factor Extraction — NEFDB Phase 1

## Source documents used

- `unfccc_asb0034_wapp_2021.md` — ASB0034-2021 standardized baseline (primary source for published rounded values).
- `unfccc_asb0034_assessment_report.md` — CDM-PSB-SA-FORM assessment report (corroboration, higher precision values, Step 6 weights).
- `unfccc_cdm_tool07_v7.md` — TOOL07 v7.0 (combined-margin equation and default weightings).

---

## Operating Margin (OM) = 0.578 tCO2/MWh

**Exact quote from source (ASB0034-2021):**

```markdown
Table 1. Grid emission factors for the electricity system of the WAPP

| Parameter   | Unit       | Description                                                    | Applicable values |
|-------------|------------|----------------------------------------------------------------|-------------------|
| EFgrid,OM,y | tCO2/MWh   | Operating margin CO2 emission factor for the WAPP power system | 0.578             |
```

**Source reference:** `unfccc_asb0034_wapp_2021.md`, section **"7. Parameters and values"**, **Table 1**.

**Corroboration:** Assessment report Step 4 states:  
> "The OM calculated for the period 2017-2019 is equal to 0.5781 tCO2/MWh."  
(`unfccc_asb0034_assessment_report.md`, Section B, Step 4)

---

## Build Margin (BM) = 0.556 tCO2/MWh

**Exact quote from source (ASB0034-2021):**

```markdown
| Parameter   | Unit       | Description                                                 | Applicable values |
|-------------|------------|-------------------------------------------------------------|-------------------|
| EFgrid,BM,y | tCO2/MWh   | Build margin CO2 emission factor for the WAPP power system  | 0.556             |
```

**Source reference:** `unfccc_asb0034_wapp_2021.md`, section **"7. Parameters and values"**, **Table 1**.

**Corroboration:** Assessment report Step 5 states:  
> "The value of BM determined for 2019 was equal to 0.5563 tCO2/MWh."  
(`unfccc_asb0034_assessment_report.md`, Section B, Step 5)

---

## Combined Margin (CM) = 0.573 tCO2/MWh

**Exact quote from source (ASB0034-2021):**

```markdown
| Applicable project types                              | Applicable values |
|-------------------------------------------------------|-------------------|
| Wind and solar power generation project activities    | 0.573             |
```

This is the wind-and-solar project combined margin for the **first crediting period**. The same ASB Table 1 also lists:

- `0.567 tCO2/MWh` — all project activities except wind and solar, first crediting period.
- `0.562 tCO2/MWh` — all project activities except wind and solar, second and third crediting periods (per assessment report).

NEFDB records the `0.573 tCO2/MWh` value because it matches the factor specified in **PLAN.md** for the WAPP-based national grid combined margin.

**Source reference:** `unfccc_asb0034_wapp_2021.md`, section **"7. Parameters and values"**, **Table 1**.

**Corroboration:** Assessment report comparison table shows:  
> `EFgrid,CM,y ... Combined margin CO2 emission factor for the WAPP power system for wind and solar projects ... 0.573`  
(`unfccc_asb0034_assessment_report.md`, paragraph 19 / comparison table)

---

## CM formula confirmation

TOOL07 v7.0 Equation (16) defines the combined margin as:

> `EFgrid,CM,y = EFgrid,OM,y × wOM + EFgrid,BM,y × wBM`

(`unfccc_cdm_tool07_v7.md`, section **6.6.1**, Equation 16).

The default weights are:

> "(a) Wind and solar power generation project activities: wOM = 0.75 and wBM = 0.25 ... for the first crediting period"  
> "(b) All other projects: wOM = 0.5 and wBM = 0.5 for the first crediting period"

(`unfccc_cdm_tool07_v7.md`, section **6.6.1**, paragraph 86; also `unfccc_asb0034_assessment_report.md`, Section B, Step 6).

**Check for the recorded CM (wind/solar):**

```
0.578 × 0.75 + 0.556 × 0.25 = 0.4335 + 0.1390 = 0.5725 tCO2/MWh
                              → rounded to 0.573 tCO2/MWh
```

**Check for the alternative general-projects CM:**

```
(0.578 + 0.556) / 2 = 0.567 tCO2/MWh
```

Both match the ASB0034-2021 Table 1 exactly.

---

## Unit conversion (tCO2/MWh → kgCO2e/kWh)

- 1 tCO2 = 1,000 kgCO2
- 1 MWh = 1,000 kWh

Therefore:

```
1 tCO2/MWh = 1,000 kgCO2 / 1,000 kWh = 1 kgCO2/kWh
```

No additional GWP adjustment is required because these factors are **CO2-only**; CH4 and N2O contributions are zero for this source.

Stored NEFDB values:

| Margin | tCO2/MWh | kgCO2e/kWh |
|--------|----------|------------|
| OM     | 0.578    | 0.578      |
| BM     | 0.556    | 0.556      |
| CM     | 0.573    | 0.573      |

---

## Deterministic notes

- All three rounded values are taken directly from ASB0034-2021 Table 1. The assessment report provides higher-precision values (0.5781 and 0.5563), but the published baseline values are rounded as above.
- No original page numbers are available in the markdown transcriptions; references are given by the nearest heading/section/table.
- The validator can reproduce every published value by re-reading ASB0034-2021 Table 1 and applying the TOOL07 weighted-average formula with the default weights.