diff --git a/doc/supply_demand.rst b/doc/supply_demand.rst index daf8aa06..56947f96 100644 --- a/doc/supply_demand.rst +++ b/doc/supply_demand.rst @@ -120,7 +120,7 @@ Pypsa-eur-sec allows individual buildings to make use of `micro gas CHPs `_ file). Generally, the COP will be lower during winter when temperatures are low. Because the ambient temperature is more volatile than the soil temperature, the COP of ground-sourced heat pumps is less variable. Moreover, the COP depends on the difference between the source and sink temperatures: +The coefficient of performance (COP) of air- and ground-sourced heat pumps depends on the ambient or soil temperature respectively. Hence, the COP is a time-varying parameter (refer to `Config `_ file). Generally, the COP will be lower during winter when temperatures are low. Because the ambient temperature is more volatile than the soil temperature, the COP of ground-sourced heat pumps is less variable. Moreover, the COP depends on the difference between the source and sink temperatures: $$ Δ T = T_(sink) − T_(source) $$