## 4 Results and Discussion
### LCA of Wind Turbines or Their Components
Energy outputs from incineration are assumed to displace the electricity and natural gas-fired heat generation, which gave a credit (\(-\)1041 kg CO2 eq./t CFRP). Mechanical recycling with landfilling of the coarse recyclate fraction and displacement of GF production resulted in a net global warming potential reduction of 378 kg CO2 eq./t CFRP. The results of a comparative analysis of environmental assessments of the life cycle of wind turbines are summarized in Table 6. The following conclusion can be drawn: increasing the capacity of wind turbines by increasing its height and the span of the blades from an environmental point of view is unreasonable since transporting bulky components of the turbine to the installation and recycling site or landfill contributes too much to the overall ecology footprint. For the same reason, it is inappropriate to build offshore wind farms far in deep waters. Contrary to the findings of [93], we did not find solid evidence that the environmental impacts of onshore wind farms are higher. This situation can only change if environmentally friendly modes of transport (for example, electric trains) are used. Overall, these findings are in accordance with findings reported by [PERSON] et al. [93]. The technologies for recycling the blades need further development. So far, it can be stated with a degree of certainty that incinerating the blades of wind turbines is an environmentally unacceptable alternative to their disposal. The development of technologies to reduce the weight of the tower for a wind turbine, for example, by improving its design, has significant prospects from the environmental point of view. A major limitation of our study is the uncertainty induced by parameters of technological, spatial, and temporal nature in LCA models of wind and solar plants. For example, recent research [94,95] suggests that there is great variability in results within sets of wind turbines with similar nominal power output. Nevertheless, we can still state several important common principles that can be applied to the eco-design on energy systems based on RES. This is particularly important when investigating new possibilities for the development of renewables in countries where the issues of eco-design have not been properly addressed yet. Applications for Eco-Design of Energy Systems and Energy Policy: The Case of Renewable Energy in Russia  
Therefore, despite the incomplete data and the presence of significant uncertainties, the available studies of the entire life cycle of solar and wind energy plants allow us to draw several general conclusions regarding the eco-design of their production systems. Firstly, recycling is much more preferable from an environmental point of view than disposal, so it must be foreseen (including in the organizational and regulatory aspects) at the earliest stages of development of the renewable energy technologies. Secondly, when choosing a location for solar and wind energy plants, it is necessary to take into account not only the climatic and infrastructural conditions but also the distance from the place of the proposed location of the recycling enterprises. Let us examine how this conclusion can be applied to the improvement of the eco-design of solar and wind energy projects in Russia. The literature review shows that there has been little discussion on the problem of RES capacity recycling in this country [96]. A reasonable explanation of this knowledge gap is an initial stage of development of wind and solar energy. To date, the most developed type of renewable energy in Russia is solar. In 2019, the volume of electricity generated by solar stations in Russia amounted to 850.38 MWh, while wind stations contributed only 209.84 MWh. Other types of