Additional information on calculating the conservative emission factor of Costa Rica for
the JCM
It is concluded that net emission reductions will be achieved by applying the following
emission factors to solar PV projects under the JCM in Costa Rica:·An emission factor of 0.255 t-CO2/MWh, in case the PV system(s) in a proposed projectis connected to the national grid including through internal grid which is not connected toa captive power generator.

·An emission factor of 0.255 t-CO2/MWh, in case the PV system(s) in a proposed projectis connected to internal grid which is connected to both the national grid and a captive
power generator.

·An emission factor of 0.533 t-CO2/MWh, in case the PV system(s) in a proposed projectis connected to an internal grid which is not connected to the national grid.

1. Current status of electric power source mix in Costa Rica
The Costa Rican Institute of Electricity (Instituto Costarricence de Electricidad, ICE), a
Costa Rican state-owned holding company, administrates the country’s electricity and energy
including electricity generation, transmission and distribution through the national grid(Figure 1). In some cases, it operates through smaller companies to distribute electricity
throughout the country.

Figure 1. Map of Costa Rican national electricity grid1
ICE has a total installed capacity of more than 2,000 MW, which represents 79.3% of the1
Approximate figure, based on Plan de Expansión de la Transmisión 2015 – 2025, Instituto Costarricense de Electricidad
Negocio de Transmisión, Proceso Expansión de la Red, 2015.

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total national electricity production. The ICE owns 100% of the country's transmission
system and provides energy to 39% of the population. Independent power producers
connected to the national grids generate the rest of the electricity.
There are six types of fuel used for national electricity generation, namely diesel, hydro,geothermal, wind, bagasse and Solar2. The share of overall electricity generated from 2013 to2015 by type of fuel used is shown in Table 1. The amount of electricity generated fromhydro, geothermal, wind, bagasse and solar power plants, defined as low cost/must run(LCMR) power sources, were 8.928 TWh (87.66% of total electricity generation) in 2013,9.075 TWh (87.51% of total) in 2014, and 10.607 TWh (97.44% of total) in 2015.
Table 1. Net electricity generation by fuel type*Net electricity generation by fuel2013
20142015
Total 2013-2015
type (TWh)**
2.347
Diesel
1.196
1.043
0.108
21.623
Hydro
6.839
6.717
8.067
4.431
Geothermal
1.517
1.538
1.376
2.300
Wind
0.485
0.735
1.080
0.252
Bagasse
0.086
0.084
0.082
0.004
Solar
0.001
0.001
0.002
0.485
Import
0.061
0.252
0.172
2.347
Total without LCMR and import
1.196
1.043
0.108
10.18510.37010.886
31.442
Total (TWh)
Source: Generacion y Demanda: Informe Anual, Centro Nacional de Control de Energia, 2015
(Generation and Demand: Annual Report, National Center for Energy Control, 2015)* There is a difference between the values listed as “Total“ and the summation of each value of“Diesel”, “Hydro”, “Geothermal”, “Wind”, “Bagasse”, “Solar”, and “Import” because thesevalues are rounded.
** Electricity generation represents a net amount which is the amount of electricity generated by apower plant that is transmitted and distributed for consumer use.

2. Calculation of emission factor of the national gridTo calculate the emission factor of Costa Rican national grid, the actual dispatch record fromdiesel power plants for the years 2013-2015 is used. There are eight diesel power plants that
supply electricity to the national grid within 2013-2015: Barranca, Garabito, Guápiles, Moín I,Moín II, Moín III, Orotina, and San Antonio. The emission factor is calculated in aconservative way by multiplying the conservative emission factor of diesel power plant andthe ratio of total hours of electricity generation by diesel power plants to the total number ofhours of electricity generation by all power plants.

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Instituto Costarricense de Electricidad. 2015. Energía Generación y Demanda, Informe Anual, Centro Nacional de Controlde Energia.

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The conservative emission factor of diesel power plants is calculated using the following
equation:
The conservative emission factor of diesel power plant [t-CO2/MWh]=(Emission factor of diesel [kg-CO2/TJ]*10-3*0.0036[TJ/MWh] / (Heat efficiency (LHV)[%]/100)
Applying the emission factor for diesel combustion of 72,600 kg-CO2/TJ, derived from
“IPCC guideline 2006, Chapter 2, stationary combustion”, and the plant heat efficiency(LHV) of 49%, which has not been achieved yet by the world’s leading diesel generator3, theemission factor of diesel generator is calculated to be 0.533 t-CO2/MWh.
Total hours of Costa Rican national electricity generation from 2013 to 2015 are summarizedin Table 2. Annual total hours of generation by thermal power plants are aggregated fromeight diesel power plants data.
Table 2. Total hours of electricity generation by thermal power plants
2013

2014

2015

Total 2013-2015

Total hours of electricity
generation by thermal (diesel)
power plants

6,316

5,060

1,199

12,575

Total hours of electricity
generation by all power plants

8,760

8,760

8,760

26,280Source: Generación Real, MWh, Sistema Eléctrico Nacional - Costa Rica Información Diaria4

The emission factor for the national grid per year is calculated using the following equation:
The emission factor for the national grid per year (t-CO2/MWh)= the conservative emission factor of diesel power plant [t-CO2/MWh] * (total hours ofelectricity generation by diesel power plants [hours] / total hours of electricity generation by
all power plants [hours])
As shown in Table 3, the default emission factor for the national grid to be applied is
calculated as the weighted average emission factor of 2013-2015, and set to be 0.255
t-CO2/MWh.

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4The approved JCM methodologies (PW_AM001, MV_AM001, and MN_AM003) also applied this value.
Available at https://appcenter.grupoice.com/CenceWeb/CencePosdespachoNacional.jsf

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Table 3. Calculated emission factor of Costa Rican national grid

Emission factor(t-CO2/MWh)

2013

2014

2015

2013-2015

0.384

0.308

0.073

0.255

3. Calculation of the emission factor of a captive power generator
To determine the emission factor of a captive power generator which normally uses a dieselgenerator in a conservative and simple manner, the heat efficiency of 49%, an efficiency level
which has not been achieved yet by the world’s leading diesel generator, is applied.
The emission factor of diesel power generation is calculated from the heat efficiency using
the following equation:
Emission factor of diesel power plant [t-CO2/MWh]=(Emission factor of diesel [kg-CO2/TJ]*10-3*0.0036[TJ/MWh] / (Heat efficiency (LHV)[%]/100)
Applying the default value of the emission factor of diesel combustion which is 72,600
kgCO2/TJ derived from “IPCC guideline 2006, Chapter 2, stationary combustion”, together
with the heat efficiency of 49%, the emission factor for a captive power generator iscalculated to be 0.533 tCO2/MWh.

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