Rough ceiling on the gas energy in Welsh sludge

190 GWh2025-26estimatelow confidence

Welsh Water reports 141.8 GWh generated from sludge, so most of any ceiling is already being recovered.

70,500 tDS × 450 m³ biogas per tDS × 60% methane × 10 kWh per m³ methane = 190 GWh. The yield, methane share and energy content are typical industry values (the first version of our model used them), not Welsh Water's own. 450 m³/tDS is probably at the high end.