Effectiveness of Renewable Energy Technologies in Reducing Greenhouse Gas Emissions: A Systematic Review of Global Evidence

Unofficial AI-generated summary based on the public title and abstract. Not an official translation.

🔬研究者:Provides a condensed evidence base on conditions under which RETs achieve emission reductions, useful for meta-analyses or model validation.

🏢実務担当者:Highlights that hybrid systems and digital integration (smart grids, AI) are critical multipliers for emission reductions beyond technology deployment alone.

🏛政策担当者:Argues that renewable energy policy should shift from capacity targets to system integration and supply chain decarbonization to meet Net Zero goals.

Background: While Renewable Energy Technologies (RETs) are central to global climate strategies, their actual effectiveness in reducing Greenhouse Gas (GHG) emissions is often complicated by lifecycle carbon costs, geographical differences, and varying levels of technological integration. Understanding the specific conditions under which these technologies perform best is critical for meeting international climate targets. Objective: This systematic review aims to consolidate recent empirical evidence on the effectiveness of different renewable energy technologies in mitigating GHG emissions, identify the primary factors that enhance or hinder their performance, and explore the implications for global energy policy. Methods: Following PRISMA guidelines, we searched Web of Science, ScienceDirect, and Google Scholar for studies published between 2017 and 2026. Inclusion criteria focused on original peer-reviewed research and high-quality reports that utilized econometric modeling or technical simulations to measure the impact of RETs on carbon intensity, CO2 emissions, or temperature anomalies. A total of 11 high-quality studies representing diverse economic regions (G7, BRICS, and developing nations) were selected for final synthesis. Findings: The review identified Solar and wind technologies appeared frequently among studies reporting substantial emission reductions; however, the relative effectiveness of renewable technologies varied according to geographical setting, technological integration, policy context, and study design. Several included studies reported that an increase in renewable energy consumption was associated with a reduction in CO₂ emissions, with effectiveness jumping significantly, up to 77% at the building scale—when hybrid systems are used. Key "multipliers" for success include institutional quality (governance and stable regulations) and digital integration (smart grids and AI). However, the review also highlights a "lifecycle paradox," where the fossil fuels used to manufacture and transport green hardware create an initial carbon debt. Furthermore, bioenergy and hydropower were found to have specific environmental trade-offs, such as land-use changes and methane leakage, which can offset their mitigation benefits if not managed carefully. Conclusion: Renewable energy is highly effective at reducing emissions, but its success is not automatic. The most significant gains occur when green hardware is supported by smart software and strong government institutions. To achieve true Net Zero, energy policy must move beyond simple installation targets and focus on system-level integration and the decarbonization of the renewable energy supply chain itself.

• crossref https://doi.org/10.9734/jenrr/2026/v18i5513first seen 2026-05-28 05:31:33 · last seen 2026-06-03 05:54:46
• semanticscholar https://doi.org/10.9734/jenrr/2026/v18i5513first seen 2026-05-30 05:22:25 · last seen 2026-06-03 05:20:18