I-DEV0384: Deviation to the measuring of total flow of LFG

The deviation is for the 6th monitoring period (01/08/2009 -31/07/2010) of registered CDM project (Ref 0071: Nanjing Tianjingwa Landfill Gas to Electricity Project). One deviation is requested:
As per ACM0001 version 01 and the registered monitoring plan, LFGtotal, y should be monitored before landfill gas (LFG) is piped into the generator, boiler and flare. There are two generators installed in the project; the flaring equipment has been installed on-site, but not used during the entire monitoring period due to insufficient gas production. There is therefore no LFGflare, and thus there is no emission reduction related to flaring of LFG. LFGtotal, y was calculated by summing measured values for LFGelectricity, y combusted by the two generators. The conservativeness check of comparing measured and calculated values for LFGtotal,y and taking the lower value for emission reduction computation could not be carried out, as this check consists of comparing LFGtotal with LFGelectricity + LFGflare, whereas in this case LFGflare = 0.
A similar deviation was submitted during the 5th verification (30/06/2008-31/07/2009) and was accepted on 18/05/2010. The reference code is I-DEV0308. Subsequently the flow meter measuring LFGtotal, y was installed in May 2010 in compliance with the applied methodology and registered PDD, but due to test operation, the flow meter was not put into use until July 2010. Therefore for the current monitoring period from 01/08/2009 to 31/07/2010, the project has to request for deviation due to the measure of total flow of LFG.

As per the Monitoring plan of the PDD, the LFGtotal, y is equal to sum of LFGflare and LFGelectricity. As indicated by the PP and verified by DOE during on site audit that due to insufficient gas production, the flaring equipment has not been used although it has been installed on site as per requirement of monitoring plan. Hence, LFGflare is equal to zero and LFGtotal is equal to LFGelectricity. Also, the results obtained confirm that this approach, given the accuracy of the meters, allow to perform the required verification in a reliable way. Furthermore, according to registered PDD MP and methodology, total flow meter is required to install to check the conservativeness between calculated values and measured values.
Since the meter was not installed, it is deviated from the registered PDD, MP and methodology, although LFGflare and LFGboiler are both zero during the 6th monitoring peroid; therefore the deviation requested. This will be verified in the next consecutive verification. However, it does not require a revision of the monitoring plan.
This deviation has been confirmed by DOE and it can be confirmed that it will be addressed and resolved by the PP by installing total flow meter as required by PDD MP.

The deviation to measure the LFGtotal, y using LFGgenerators flow meters (LFGtotal= LFGflare (0) + LFGelectricity (LFGelectricity, Gen-1 and LFGelectricity, Gen-2)) instead of the total flow meter has no impact on the estimation of the Emission Reductions for the 6th monitoring period. Also, there is no difference between the emission reductions claimed with or without an overall flow meter. This is because the meter aims to check LFGtotal against LFGflare + LFGelectricity. In this case due to insufficient gas production there were no flaring and hence LFGflare = 0, and LFGtotal = LFG electricity (=LFGgenerators). Furthermore, according to the most recent version of the methodology ACM0001, Version 11, page 15 “In the case where LFG is just flared, one flow meter for each flare can be used provided that these meters used are calibrated periodically by an officially accredited entity” Hence, in the opinion of the DOE the same can be applied for LFG combusted in generators.
In this case, both flow meters were calibrated periodically as per monitoring plan requirement by an officially accredited entity and hence reading recorded by both meters can be trusted and verified. Furthermore, the main line of the total amount of LFG capture is later divided into two lines to the generators. Two separate meters have been installed to measure LFG combusted by these two generators. LFGelectricity, y is measured by calculating the sum of LFG measured by the two separate flow meters. Since there is no LFGflare, LFGelectricity,y = LFGtotal,y. Therefore, the conservativeness check of comparing measured and calculated values for LFGtotal, y is not necessary or possible, considering the flare is not in use. Furthermore, the monitoring instruments have been correctly installed and calibrated periodically (see monitoring report).
Based on above considerations this deviation has no impact on the estimates of the emission reductions for the project.
Furthermore, the PP has conforms that total flow meter has been installed and that has been verified during the 6th verification site visit.