# Supply Chain Management in Renewable Energy Projects from a Life Cycle Perspective: A Review
## 3 Results
#### Key Phases of the Renewable Energy Supply Chain  
1. Extraction and Processing of Materials: This phase involves obtaining essential natural resources for the manufacturing of RE components. It includes mining, refining, and purification of various materials. Critical materials are essential for manufacturing batteries used in RE storage [147; 148; 149]. Rare earth elements are essential components in high-efficiency wind turbines and electric vehicles. China currently controls approximately 70% of global production, raising concerns about the long-term security of supply. It is important to emphasize that the environmental benefits of electric vehicles are only fully realized when the electricity that powers them is generated from RE sources such as wind, hydro, or solar energy [150; 151; 152; 153; 154; 155]. Otherwise, the transition from internal combustion engines to electric mobility may merely shift CO2 and other GHG emissions from vehicle tailpipes to fossil fuel-based power plants. From this perspective, the contribution of electric mobility to climate change mitigation is significant only when accompanied by a broader energy transition toward clean electricity generation [156; 157; 158; 159; 160]. 2. Component Manufacturing: After obtaining raw materials, the manufacturing of various components necessary for RE systems takes place. This process includes the production of solar panels, wind turbines, batteries, inverters, and other essential elements for the generation and storage of renewable energy [161; 162; 163]. 3. Transportation and Construction: This stage covers the transportation of the manufactured components to the installation site and their assembly. In photovoltaic systems,  
Figure 1: Phases for the LCA of renewable energies. this involves the installation of solar panels and the integration of balance-of-system (BOS) components, such as mounting structures and wiring. In wind energy, in addition to the installation of turbines, the construction of foundations is required, which often involves significant use of cement and steel reinforcement [164]. This phase can generate emissions due to the transportation of materials and the use of heavy machinery during installation [165]. 4. Operation and Maintenance: These activities are carried out during the operational life of RE installations to ensure their efficiency and functionality. These activities include regular cleaning of solar panels, technical inspections, adjustments to electrical systems, and proper lubrication of moving parts [166; 167; 168; 169; 170; 171; 172; 173]. 5. Decommissioning and End of Life: At the end of the operational life of RE installations, proper decommissioning is essential. This process includes the removal of equipment, recycling, and the potential recovery of land [174; 175; 176; 177; 178]. Efficient management of this phase is key to minimizing environmental impact and maximizing the use of recyclable materials. However, the recycling of certain RE components remains a technological and logistical challenge at present [179; 180; 181; 182]. These stages highlight the complexity of assessing the environmental impact of RE technologies [183; 184; 185]. They emphasize the need to consider the entire life cycle to understand the environmental costs and benefits. Through LCA, it is possible to identify key aspects such as the \"environmental hotspots\" of renewable energies, i.e., the phases or stages of the life cycle where the greatest impact is concentrated in terms of carbon footprint, water usage, energy consumption, and waste generation [186; 187; 188]. Taking solar energy as an example, it is estimated that photovoltaic panel waste could reach 78 million tons worldwide by 2050 [189; 190]. If fully reintroduced into the economy, the value of recovered material could exceed $15 billion [191; 192]. This potential influx of material could produce 2 billion new panels or be sold in global raw material markets, increasing the future supply security of photovoltaic panels or other products [193; 194; 195; 196].