Transformation of a University Lecture Hall in Valladolid (Spain) into a NZEB: LCA of a BIPV System Integrated in Its Façade

Table 4

Impact of BIPV system lifetime assumption on the emission factor, considering a reduction in the module efficiency of 0.7% per year.

System lifetime (years)	Power generation over lifetime (kWh)	Total GHG emissions (kg CO2)	Emission factor (kg CO2/kWh)	Δ emission factor^† (%)
25	296,694	51,729	0.178	15.77
26	307,513	51,926	0.171	12.12
27	318,255	52,124	0.166	8.75
28	328,922	52,321	0.160	5.62
29	339,515	52,519	0.155	2.92
30	350,033	52,716	0.151	—
31	360,478	52,914	0.146	−2.53
32	370,850	53,111	0.142	−4.91
33	381,149	53,309	0.138	−7.13
34	391,376	53,506	0.135	−9.22
35	401,531	53,704	0.131	−11.19

^†Taking a 30-year system lifetime as a reference.