I-DEV0270: Monitoring fuel consumption through flow meters under inappropriate accuracy control

A deviation is requested with regard to inappropriate accuracy control practices and resulting adjustments of the fuel consumption records.
In the registered PDD, it was pledged that the main fuel flow meter in the boiler room shall be calibrated with a one-year interval on site using a special apparatus as a part of regular energy conservation system maintenance (page 18). However, during the course of verification, DNV found out the following facts:

- four flow meters, each of which was attached to a boiler, were originally equipped (old sub-meters) at the time of project start date (7 April 2007);
- a total flow meter (main flow meter) was newly installed on 5 September 2007 for the purpose of double-checking the fuel consumption data;
- all four of the old sub-meters were replaced on 8 March 2008 (new sub-meters); and
- fuel oil consumption records stored in the data acquisition system were sourced from sub-meters.

These findings clearly deviate from the provision of the monitoring plan in the registered PDD.

The following evidences have been provided to DNV during the verification and DNV found them relevant.
- Meter Calibration Test Ticket for the main flow meter
- Flow Meter Calibration Report for all four of the new sub-meters

To compensate for it, difference in meter readings between old sub-meters and the main flow meter, whose accuracy was certified, has been investigated over the period from September to February. It turned out that data from the old sub-meters deviated from the one from the main flow meter by 0.49%. For conservativeness, the project proponent decided to apply the factor of 1.01 (1% addition project emission, instead of 0.49%) to the sub-meter readings throughout the reporting period of 7 April 2007 to 31 March 2008.

This deviation is only for this verification period. New meters were installed before this verification period ended and these will be used for the next verification periods.

Investigation on difference in meter readings between old sub-meters and the main flow meter covered the period from 5 September 2007 to 8 March 2008, more than 50% of the whole monitoring period of 7 April 2007 up to 31 March 2008. Hence the difference can fairly represent the difference throughout the monitoring period. Besides, the project proponent applied the correction factor of 1% although the actual difference examined was a mere 0.49%. This is deemed conservative.
In this respect, the proposed request for deviation will be very unlikely to lead to over-estimation of the emission redustions for the proposed project activity.