Table 1 Metrics commonly used to evaluate GHG emissions in hydropower projects
From: Reducing greenhouse gas emissions of Amazon hydropower with strategic dam planning
Metric | Units | Description |
|---|---|---|
GHG flux | kg CO2eq km−2 d−1 | The exchange of GHG, in CO2 equivalents, at the reservoir air-water interface per unit of surface area over a certain time period. The direction of GHG flux can be from water to atmosphere (emission or efflux; positive value) or from atmosphere to water (uptake or influx; negative value). |
Total GHG flux | Tg CO2eq | GHG flux over a reference time period multiplied by the total reservoir area. The reference times considered here are a day and 1, 20, and 100 years (1 Tg = 1012 g). |
Power density | MW km−2 | The ratio of electricity generation capacity to reservoir flooded area. This metric reflects the strong link between GHG emissions and flooded area and is often used as a simple proxy for carbon intensity. |
Carbon intensity | kg CO2eq MWh−1 | Also known as emission intensity or emission factor. CO2-equivalent emissions produced per unit electricity generated. This metric is used to compare emissions performance across projects of different sizes, and also among electricity sources. |
