## 6 Conclusions  
This paper, motivated by environmental degradation, European and local policies to address it and the recent energy crisis, presents the economic results of the implementation of green procurement in projects carried out in Greek public institutions. As European directives encourage the use of LCC tools, since their use is still far from being systematic, those developed by the European Commission were selected and used. This approach was employed to explore the economic benefits of using green products, which are traditionally considered expensive and therefore not the first choice of operators due to their high acquisition cost. While procurement contracts are still awarded on the basis of the most economically advantageous offer, life-cycle costing takes into account all the costs that will be incurred during the lifetime of the product, project or service.  
The findings of this research demonstrate that the use of green products by public operators should be implemented methodically at a strategic level. Although at a first glance green products are not economically viable in some cases, a second reading leads to different conclusions. In many cases they turn to be a streamlined choice, since indirect costs in most cases represent a higher percentage of total costs in non-green products. Furthermore, the fact that purchases of green products were fragmented showcases the need for centralized procurement management in order to exploit economies of scale. Decision-makers have various tools at their disposal, and they can consider the long-term effects of alternative choices. This is definitely a more rational and efficient approach, which is in line with sustainability mandates. Moreover, this sophistication in public procurement can stimulate competition and technological advances, leading to additional benefits that it is not easy to quantify. They can be rather considered as drivers towards improved practices with obvious positive impacts for societies at large.  
The limited availability of information on public procurement of green products in Greece was an important limitation in the data analysis. Nevertheless, the results obtained are the first official and measurable indicators of the implementation of the GPP strategy in Greece. Future research should use LCC tools to analyze the implications of alternative procurement policies along with extended data availability.  
**Author Contributions:** Conceptualization, V.S.O. and N.P.R.; methodology, V.S.O., N.P.R. and G.T.T.; software, V.S.O.; validation, V.S.O., N.P.R. and G.T.T.; formal analysis, V.S.O., N.P.R. and G.T.T.; investigation, V.S.O.; resources, V.S.O.; writing--original draft preparation, V.S.O.; writing--review and editing, V.S.O., N.P.R., G.T.T. and G.P.C.; visualization, V.S.O., N.P.R. and G.T.T.; supervision, N.P.R. and G.P.C. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This research received no external funding.  
**Institutional Review Board Statement:** Not applicable.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** No new data were created.  
**Conflicts of Interest:** The authors declare no conflict of interest.
Figure A2: (i,ii) Indicative illustration of the results of LCC implementation in the procurement of office equipment.