When comparing water usage, coal-fired power plants consume significantly more water than nuclear power plants—both for cooling and steam generation. Here’s a detailed breakdown:
https://www.sciencedirect.com/science/article/pii/S13640321193059941. Water Consumption: Coal vs. Nuclear
Metric Coal Power Plants Nuclear Power Plants Withdrawal (gal/MWh) 20,000 – 50,000 25,000 – 60,000 Consumption (gal/MWh) 300 – 1,100 400 – 800 Key Difference Higher consumption due to inefficiency More withdrawal but less consumed (closed-loop cooling) Why?
Coal plants waste more heat (lower thermal efficiency ~33-40%), requiring more water to cool and condense steam.
Nuclear plants run hotter (efficiency ~32-38%) but often use recirculating cooling (water reused, not lost).
2. Water Use Breakdown
Coal Plants
Once-through cooling: Withdraws massive amounts (e.g., 50K gal/MWh) but returns most (still warms ecosystems).
Wet cooling towers: Consumes 500–1,100 gal/MWh via evaporation.
Additional uses: Coal washing, emissions scrubbing (e.g., flue-gas desulfurization).
Nuclear Plants
Closed-loop systems: Withdraw more water but reuse it (consuming 400–800 gal/MWh).
Dry cooling (rare): Cuts consumption by ~90% but reduces efficiency.
3. Real-World Examples
A typical 500 MW coal plant consumes ~1.4 billion gallons/year (equal to ~30,000 Olympic pools).
A similar nuclear plant uses ~1.0 billion gallons/year but returns most to the source.
4. Key Takeaways
Coal wins (loses?) on consumption: Burns more water per MWh due to inefficiency.
Nuclear withdraws more but wastes less: Better for drought-prone areas if using cooling towers.
Bottom Line
For net water consumption, coal is thirstier. For ecological impact (thermal pollution), nuclear’s withdrawals can stress local waterways.
