Four scenarios were considered to show the individual influence of each one of the different variables:

• Scenario 1: NO AID: no financial aid was considered, taking only into account the energy savings resulting from the substitution of the mechanical vapour compression machine by the solar absorption cooling system.

• Scenario 2: SUBSIDY: apart from the reduction of energy consumption caused by the change of technology, a public subsidy of 50% of the cost of the solar field was considered.

• Scenario 3: SBS_CHT_SHW: the reduction of energy consumption from the use of the solar field to pre-heat the sanitary and the central heating hot water is considered as an economic saving which was added to the cooling energy savings and the public subsidy for installing the solar field

• Scenario 4: CHT_SHW: due to the uncertainty in the granting of the subsidy, in this scenario only the energy savings are considered, including the support to sanitary and central heating hot water, and assuming that there is no public subsidy for the system.

Fig. 3.a Cumulative savings: subsidy and complementary uses of the solar field — absolute value Fig. 3.b Cumulative savings: subsidy and complementary uses of the solar field — relative value