Renewable is not the same as sustainable
The distinction that changes the conversation about energy.
Sorted from dirtiest to cleanest — nuclear and wind side by side.
There is a common misconception: that all renewable energy is automatically sustainable — and that nuclear is not.
- Renewable = the source does not run out (sun, wind, water).
- Sustainable = meets demand consistently, with minimal impact over the full lifecycle.
Lifecycle CO₂ comparison:
| Source | g CO₂ / kWh |
|---|---|
| Coal | 820 |
| Natural gas | 490 |
| Solar | 48 |
| Hydroelectric | 24 |
| Nuclear | 12 (IPCC median) |
| Wind | 11 |
Source: IPCC; Our World in Data, 2024.
Nuclear is not renewable in the strict sense. But in terms of carbon footprint, it is as clean as wind. And unlike solar and wind, it works 24/7 regardless of the weather.
And fusion? Deuterium exists in all the water on the planet in virtually inexhaustible quantities. It would be renewable and sustainable at the same time.
Which source has the lowest CO₂ footprint per kWh, alongside wind?
Nuclear fusion is the answer science is building right now.