ANNEX 5: DETAILED CO2 CALCULATONS AND ASSUMPTIONS

ANNEX 5: DETAILED CO2 CALCULATONS AND ASSUMPTIONS

1. 
   Direct Emission Reductions
   

2. 
   Direct post-project emission reductions
   

Since the project does include activities that would directly result in GHG emission reductions after the completion of the Project, direct post-project GHG reductions are expected. They have been calculated as follows:

• 
  Base case - With no estimates of MWh generated from proposed 50 MW CSP plants, assumptions on MWh generated were made using an average net capacity factor of 40% based on July 2012 Pre-feasibility CSP Overview by MME (on pg 5) that assumes CSP plant has thermal storage to meet peak demand in the evening;
  
• 
  First CSP plant commissioned in 2016;
  
• 
  Two other 50 MW CSP plants were assumed to be commissioned in 2017 and 2018;
  
• 
  Average number of hours that CSP plant is 24 hrs, 365 days per year;
  
• 
  Grid emission factor is 1.0136 t CO_2eq /MWh⁵⁵ that assumes carbon reductions are resulting from the offsetting of power imported from South African thermal power stations;
  
• 
  One 50 MW plant will generate 175,200 MWh annually (50 MW x 24 hrs x 365 days x 0.40);
  
• 
  With the 1.0136 t CO_2eq /MWh grid emission factor, emission reductions are 177,583 t CO_2eq annually from each 50 MW CSP plant.
  

According to the June 2012 IRENA CSP report (http://www.irena.org/DocumentDownloads/Publications/RE_Technologies_Cost_Analysis-CSP.pdf), the ranges of CSP capacity factors with storage for parabolic troughs and solar towers are 40-53% and 40-45% respectively for 6-hour storage. While a final technology option has not been selected for this pilot CSP project, the MME’s CSP Pre-Feasibility Study of July 2012 leans heavily towards parabolic troughs and power towers and molten salts for cooling given that these are the most commercially advanced CSP technologies available. As such this is the most likely scenario and is labelled the “base case.” If the parabolic trough technology with no storage is implemented, the capacity factor is projected to be in the range of 20-25%.

- The 10-year cumulative GHG emission reductions from three CSP projects implemented over the next 3 years after the end of the Project will range from 4.79 million tons CO2eq (with storage) to 2.40 million tons CO2eq (without storage).

3. 
   Indirect emission reductions (bottom-up)
   

Indirect emission reductions were calculated by assuming a “top-down” 60% causality factor (“substantial but modest”). The P10 based on 3 CSP plants (base case assumptions) constructed after the end of CSP TT NAM is 4.795 million tonnes CO_2eq. After applying the 60% causality factor, indirect emission reductions from this project were calculated to be 2.877 million tonnes CO_2eq.