# Diesel stationary emission factor: kWh derivation

## Per-litre starting point

- Factor ID: `ng.fuel.diesel.stationary`
- Value: **2.662 kgCO2e / litre**
- Primary source: IPCC 2006 Guidelines Vol 2 Ch 2 Stationary Combustion, Table 2.2 (gas/diesel oil)
- Cross-checked with: DEFRA 2024 100% mineral diesel factor

## DEFRA thermal constant

- DEFRA 2024 gives **9.927 kWh thermal per litre** of diesel.

## Arithmetic

### Rated efficiency (33%)

```
kgCO2e / kWh_e = 2.662 / (9.927 x 0.33)
               = 2.662 / 3.27591
               = 0.8129
               ≈ 0.813 kgCO2e / kWh
```

### Field efficiency (28%)

```
kgCO2e / kWh_e = 2.662 / (9.927 x 0.28)
               = 2.662 / 2.77956
               = 0.9577
               ≈ 0.958 kgCO2e / kWh
```

## Efficiency assumptions

- **33% rated efficiency**: NEFDB assumption for modern/newer generator nameplate performance.
- **28% field efficiency**: NEFDB assumption for Nigeria's aged on-site genset fleet, informed by Somorin et al. 2017.

**Note:** The local copy of Somorin et al. (2017) does not state 28% efficiency explicitly; the 28% figure is a NEFDB operational assumption grounded in that study's broader findings on self-generated electricity in Nigeria.

## Recommended default

Use `ng.fuel.diesel.stationary.kwh.field` (0.958 kgCO2e/kWh) as the default for Nigerian stationary diesel generator reporting.