Biogas Tanks in Guizhou Province in China

Audit Analysis

This Gold Standard biogas project in Guizhou, China, has a verified additionality assessment but suffers from serious permanence concerns (35 tanks permanently out of service, 46% winter failure rate) with no buffer pool to cover reversals. Leakage was not addressed in the later PDD revision, and the project-specific baseline contained documented errors in seasonal fuel consumption. Multiple contradictions across monitoring and verification reports, combined with a shift in the fuel-to-net-replacement-benefit factor from a local field value to a lower national default, raise over-crediting risk.

Project Description

Red Flags

• ⚠35 glass-fibre biogas tanks permanently out of service and replaced with concrete tanks, with no buffer pool to cover the resulting credit reversals
• ⚠46% winter failure rate in Danzhai attributed to cold weather and structural issues with glass-fibre tanks, indicating systemic equipment risk
• ⚠Leakage was not addressed in the later PDD revision (November 2009), despite being deemed negligible in the earlier PDD (January 2009)
• ⚠Baseline survey errors: Danzhai used annual averages instead of seasonal averages, and Weining excluded fuel used for animal feed, both distorting the emission reduction calculation
• ⚠FNRB value dropped from 85 (local field, PDD 2009) to 63.19 (national default, monitoring 2014), increasing the credit output per unit of fuel displaced

Credit Vintages Exhausted