Variable Naming in CEA

This is a guide on how to name variables in CEA. Please do read / print before adding new varaibles to the code.

Demand Side Load Nomenclature

The variables that fall under this classification follow the syntax provided below:

(LOAD TYPE)(LOAD)_(LOSSES)_(UNITS)

The different values these parameters can take are enlisted below. The list is not exhaustive but will serve as a guide

Load Type:

Q Thermal
E Electrical

Load

al appliances
cdata data cooling
cs space cooling
cre refrigeration
hs space heating
l lighting
pro industrial processes
T total
ww hot water

Losses

sys including losses (emission, distribution and storage inside the building)
‘’ if not used, then it is an end-use demand without losses

Units

W Watt
kWh kilo Watt hour
MWhyr Mega Watt hour per year

For Example:

El_sys_W : End-use demand of electricity required for lighting including system losses (in Watts)

El_W : End-use demand of electricity required for lighting without system losses (in Watts)

ET_sys_MWhyr : Total end-use demand of electricity required including system losses (in MWh per year)

Supply Side Load Nomenclature

The variables that fall under this classification follow the syntax provided below:

(LOAD TYPE)(LOAD)_(GENERATION UNIT)_(LOAD DIRECTION)_(UNITS)

The different values these parameters can take are enlisted below. The list is not exhaustive but will serve as a guide

Load Type:

Q Thermal
E Electrical

Load

al appliances
cdata data cooling
cs space cooling
cre refrigeration
hs space heating
l lighting
pro industrial processes
T total
ww hot water

Generation Unit

PV Photovoltaic
PVT Photovoltaic Thermal
SC Solar Collector
CCGT Combined Cycle Gas Turbine
FC Fuel Cell
GSHP Ground Source Heat Pump
BASEBOILER Base Boiler
PEAKBOILER Peak Boiler
BACKUPBOILER Backup Boiler
VCC Vapor Compression Chiller

Load Direction

GRID to the local grid
DIRECT to the direct load

Units

W Watt
kWh kilo Watt hour
MWhyr Mega Watt hour per year

For Example:

Qww_PVT_DIRECT_MWhyr : Heat generated by PVT supplied to the directload of hot water demand (MWhyr)

ET_PV_GRID_MWhyr : Total electricity generated by PV which is supplied to the local power grid (MWhyr)

Supply Side Cost Nomenclature

The variables that fall under this classification follow the syntax provided below:

(COSTS TYPE 1)_(COSTS TYPE 2)_(COSTS TYPE 3)_(GENERATION UNIT)_(UNITS)

The different values these parameters can take are enlisted below. The list is not exhaustive but will serve as a guide

Costs Type 1

Capex Capital Expenditure
Opex Operational Expenditure

Costs Type 2

T Total
A Annualized

Costs Type 3

Var Variable
Fix Fixed

Generation Unit

PV Photovoltaic
PVT Photovoltaic Thermal
SC Solar Collector
CCGT Combined Cycle Gas Turbine
FC Fuel Cell
GSHP Ground Source Heat Pump
BASEBOILER Base Boiler
PEAKBOILER Peak Boiler
BACKUPBOILER Backup Boiler
VCC Vapor Compression Chiller

Units

USD US Dollar (2015)
MUSD Million US Dollar (2015)

For Example:

Capex_A_Fix_CCGT_MUSD : Annualized CAPEX (fixed component) for CCGT equipment (in million USD)

Opex_T_Var_FC_USD : Total OPEX (variable component) of FC equipment (in USD)

Supply Side Fuel Nomenclature

The variables that fall under this classification follow the syntax provided below:

(FUEL TYPE)_(FUEL DIRECTION)_(GENERATION UNIT)_(UNITS)

The different values these parameters can take are enlisted below. The list is not exhaustive but will serve as a guide

Fuel Type

NG Natural Gas
Wood Wood

Fuel Direction

used Fuel is used by the generation unit
gen resource is generated by the generation unit

Generation Unit

PV Photovoltaic
PVT Photovoltaic Thermal
SC Solar Collector
CCGT Combined Cycle Gas Turbine
FC Fuel Cell
GSHP Ground Source Heat Pump
BASEBOILER Base Boiler
PEAKBOILER Peak Boiler
BACKUPBOILER Backup Boiler
VCC Vapor Compression Chiller

Units

W Watt
kWh kilo Watt hour
MWhyr Mega Watt hour per year

For Example:

NG_used_HPSew_W : Natural gas used by sewage heat pump (in Watts)

Wood_used_Furnace_W : Wood used by Furnace (in Watts)

Supply Side Emissions Nomenclature

(LCA TYPE)_(GENERATION UNIT)_(UNITS)

LCA Type

GHG Green house gas emissions
PEN Primary Energy

Generation Unit

PV Photovoltaic
PVT Photovoltaic Thermal
SC Solar Collector
CCGT Combined Cycle Gas Turbine
FC Fuel Cell
GSHP Ground Source Heat Pump
BASEBOILER Base Boiler
PEAKBOILER Peak Boiler
BACKUPBOILER Backup Boiler
VCC Vapor Compression Chiller

Units

tonCO2 tons of CO2 equivalent
MJoil Mega Joules of oil equivalent
GJoil Giga Joules of oil equivalent

For Example:

GHG_PVT_tonCO2 : Green house gas emissions of PVT (in tons of CO2 equivalent)

PEN_PV_MJoil : Primary Energy corresponding to PV (in Mega Joules of Oil equivalent)