2.2.5. End of Life

Table 3 illustrates the type of treatment, values, and literature references considered for each raw material. Average UK values for recycling, incineration, and landfilling were used for each raw material. The wastewater treatment associated with the end of life of the heat transfer fluid (propylene glycol) has also been considered. The "net scrap" approach was applied for recycling [41], meaning that only the percentage of recycled material that exceeds the recycled content in the original raw materials has been credited to the system. The environmental impact associated with the recycling process has also been included and, in the case of incineration, the amount of energy produced during the process (heat and electricity) has been attributed to the system. The Ecoinvent 3.7 database [24] has been considered for all waste and wastewater treatment methods.

**Table 3.** End of life treatment for different raw materials in the UK.

