1) Example: Calculation of energy-saving, by solar thermal installation, for a 4 bedrooms-home in the province of Málaga

It applies the current valid regulation, Building Technical Code

- Domestic hot water needs:

Single-family: 30 liters of hot water/person and day

Number of bedrooms: 4

Daily total consumption: 180 liters of domestic hot water (60°C)

Annual total power: 12250 MJ

-Considerations for calculation of heat insolation:

Province of Malaga: climate zone IV

Orientation: Predominantly South, from + 30° to - 30°

Flat solar collector slope: between 30° and 45°

-Energy-saving:

Kit of first marks composed of two flat solar collectors and 300 liter tank. Fully assembled and installed. Variable prices. To consult.

Energy saved annually (80%): 9.800 MJ

Auxiliary power (20%): 2.450 MJ

Butane gas price*: 1,156 €/kg

(*Calculated price according to BOE, 21.11.2017. Included 21% tax and special tax for hydrocarbon fuels.)

(Calorific value of butane gas: 49.608 kJ/kg)

First year savings: 9.800MJ = 197,55kg = 228,4€ at the first year

Amortization equipment **: 6,8 years

(** It is considered a kit of 2.100€ with taxes. It is considered the rise of the annual 10% of the price of butane gas)

Saving at the end of the minimum life-period of 20 years: 10.982€

Due to the increase in the price of gas is becoming more pronounced, the SAVINGS will be EVEN MUCH MORE.

-Saving of CO2 emissions:

9800MJ from butane gas = 197.5kg of butane gas

197.5kg of butane gas, equivalent to 585.4kg of CO2 every year, which will not be dumped into the atmosphere.