Worldwide carbon neutrality transition? Energy efficiency, renewable, carbon trading and advanced energy policies

Climate change and energy shortage crisis promptly necessitate achievement of sustainable development goals. However, there is no straightforward pathways for low-carbon transformation on building sectors, and energy/carbon trading and reverse promotion on decarbonization strategies are not clear. In this study, a literature enumeration method with dialectical analysis was adopted for state-of-the-art literature review and comparison. Low-carbon transformation pathways in buildings were holistically reviewed, with a series of integrated techniques, such as energy saving, clean energy supply, flexible demand response for high self-consumption, and even smart electric vehicle (EV) integration. Afterwards, energy/carbon flows and trading in building-related systems were provided, such as peer-to-peer energy trading, building and thermal/power grids, building and energy-integrated EVs, and carbon trading in buildings. Last but not the least, worldwide decarbonization roadmaps across regions and countries are analysed, to identify the most critical aspects and immediate actions on decarbonization. Results indicate that tradeoff strategies are required to compromise the confliction between insufficient feed-in tariff (FiT) incentives (low renewable penetration in the market) and great economic pressures (high investment in renewable systems). Low-carbon building pathway is further enhanced with first priority given to passive/active energy-saving strategies, onsite clean energy supply and then flexible demand response. Energy/carbon trading will significantly affect renewable energy utilization, and acceptance from end-users to actively install renewable systems or participate in EV interactions. Worldwide decarbonization pathways mainly focus on industries, transportation, buildings, renewable sources, carbon sink and carbon capture, utilization and storage (CCUS). This study can contribute to technical roadmaps and strategies on carbon neutrality transition in both academia and industry, together with advanced policies in grid feed-in tariff, energy/carbon trading and business models worldwide.