I-DEV0311: Monitoring of Net Calorific Value of the biomass (NCVk)

Description of the request for deviation:
Prior to submitting request for issuance for the first monitoring period, 10 May 2008 to 9 May 2009, the deviation to the monitoring plan of the registered PDD “Surat Thani Biomass Power Generation Project in Thailand” is requested. The approved consolidated methodology ACM0006 / Version 04 is applied.

Monitoring of Net Calorific Value of the biomass:
In the registered PDD, the Net Calorific Value (NCV) in dry basis shall be measured at least every six months, taking at least three samples for each measurement. The NCV value is used for calculation of project emissions from combustion of biomass at the project plant.

In this monitoring period, NCV measurement for EFB was conducted in accordance with the methodology from the beginning of the monitoring period until 15 Oct 2008 for 3 samples each as presented in below table. However, the next NCV measurement was not done within 6 months after 15 Oct 2008 (due in April of 2009), instead, was actually done on 18 September 2009.

Please see Enclosure 1.

In addition, the project is combusting palm kernel shell (referred as “Shell”) and palm fiber (referred as “Fiber”) as a supplemental biomass residue of which the amount combusted accounts for less than 5% of EFB respectively.
The NCV measurement for both Shell and Fiber was conducted on 2 June 2008 as below, however with only 2 samples each. And thus, the number of samples did not comply with “at least 3” stated in the monitoring plan as well as the methodology applied until 18 September 2009.

Please see Enclosure 2.

It is noted that the requirement of the methodology is to determine the annual mean value of NCV in dry basis and it is used for calculation of project emissions due to combustion of the biomass. In this case, application of higher NCV values will have higher project emissions and can be considered more conservative approach.
In order to compensate NCV measurements for approximately 5 months’ delay for EFB (from April of 2009 to September of 2009) and the insufficient number of samples for both Shell and Fiber, the project proponent would like to apply for EB approval of a deviation which allows PPs to use the most conservative default value for NCV. As shown in below table, the IPCC guideline provides NCV values for four types of solid fuels. The value for “Other Primary Solid Biomass” should be chosen as it is most relevant fuel type to EFB, Shell and Fiber in the table. Also, the Upper value, the highest of amongst three different value, 23.0TJ/Gg, is selected to be most conservative in calculation of project emissions. Compared with above table, it could be figured out that this default value (23.0TJ/Gg) is much higher than the measured one.

Please see Enclosure 3.

To confirm the conservativeness of above proposed choice of NCV for this monitoring period, the project proponent had also studied publicly available data source. As it can be seen in below table, the data presented at the international conference shows that the NCV value for shell and fibres are slightly higher than that of EFB, however, are by far lower than that of the value we have selected from the IPCC. Therefore, the project proponent considers applying the same value from IPCC default, 23.0TJ/Gg, to be also the most conservative choice.

Please see Enclosure 4.

Furthermore, the project proponent had conducted NCV measurement for actual samples of biomass taken from the project on 18 September 2009 which is outside this monitoring period. The measurement was conducted for 3 samples each for Empty Fruit Bunch, Fibre, and Shell respectively. The full analysis results are presented in Attachment 1. Below table shows its summary.

Please see Enclosure 5.

As it can be seen, the highest value in each measurement are still much lower than 23.0TJ/Gg. With these results, the project proponent has reconfirmed conservativeness of our selection of IPCC default as the value for calculation of the project emission for this monitoring period (10 May 2008 to 9 May 2009) as well as part of the subsequent monitoring period (10 May 2009 to 18 September 2009) as follows;.
For EFB, 23.0 TJ/Gg is to be applied for the delay for approx 5 months from 14th April 2009 which was due date to the next NCV measurement done on 18th September 2009
For both Shell and Fiber, 23.0 TJ/Gg is to be applied for the entire period from of 10 May 2008 to 18 September 2009 including the entire 1st monitoring period and the first part of the next monitoring period planned.

The deviation occurs because PPs failed to measure NCV of 3 biomass residue combusted in accordance with the monitoring plan stated in registered PDD due to the delay and the insufficiency of the number of samplings which affects to the 1st monitoring period and the part of the 2nd monitoring period planned. In remained crediting period, the monitoring procedure: At least every six months, taking at least three samples for each measurement.” will be fully followed. Hence, the request is not a revision to the monitoring plan or the changes from the project activity.

The conservative IPCC default, the highest value of NCV (23.0TJ/Gg) will be applied as NCV of EFB for the period from 15 April 2009 which was the due date of NCV measurement (6 month after the last NCV measurement) to 18 Sep. 2009 which was the actual date of the next NCV measurement done. And the same value will be applied as NCV of both Shell and Fiber for the period from 10 May 2008 which is the start date of the 1st monitoring period to 18 Sep. 2009 which was the date of the next NCV measurement done with 3 samples each.
NCV value is to be used to determine EFCH4,BF :“CH4 emission factor for the combustion of biomass residues in the project plant” which is part of project emissions and thus higher NCV is more conservative. And the conservative IPCC default 23.0TJ/Gg as the upper limit of 95% confidence interval defined in the Table 1.2 in Chapter 1 of Volume 2 of 2006 IPCC Guideline is comfortably higher than the highest values among the measured values (the measurements were carried out on 20 May 2008, 2 June 2008, 15 Oct. 2008 and 18 Sept. 2009 respectively).
Therefore, the deviation being applied will lead to a more conservative emission reduction result.
In accordance with registered PDD, the annual project emissions due to CH4 emission from biomass combustion is estimated to be 3,003 tCO2e/year which accounts for approx. 3% of the annual emission reductions. Thus, the impact due to this deviation is limited and conservative.