To minimize the impacts of climate change, it is increasingly clear that global CO₂ emissions should be eliminated by 2050 and that leading low-carbon cities should reach net zero emissions by 2040. However, the precise pathways by which they can reach such ambitious goals have yet to be identified. As costs of photovoltaics (PV), batteries, and electric vehicles (EVs) are likely to keep falling, they can jointly play a key role for deep decarbonization. Here, we conduct a techno-economic analysis of a city-scale energy system with roof-top PV, batteries, and EVs for Kyoto City, Japan. We find that aggressive EV adoption and the use of EVs for electricity storage could help roof-top PV penetration in the city with substantially lower costs than just deploying PV and batteries alone or allowing EV to charge only. CO₂ emissions from vehicle and electricity usage in the city could be reduced by 60–74% if the entire current car fleet is replaced by EVs while also reducing energy costs by 22–37% by 2030. The largest challenge of a city-wide “PV + EV” system (named as “Solar-EV city”) is its implementation. We explore how it could be realized in Kyoto through peer-to-peer (P2P) power trading/blockchain technology initially on a community scale as smart microgrids, then gradually expanding/converging into a city-wide. For the transition to decentralized power systems, citizen’s decision-making process is one of the keys to overcome social, institutional, and regulatory barriers.

为了最大程度地减少气候变化的影响，全球二氧化碳₂越来越明显到2050年应消除温室气体排放，到2040年领先的低碳城市应达到净零排放。但是，尚未确定实现这些宏伟目标的确切途径。由于光伏（PV），电池和电动汽车（EV）的成本可能会持续下降，因此它们可以共同为深度脱碳发挥关键作用。在这里，我们对日本京都市具有屋顶光伏，电池和电动汽车的城市规模能源系统进行了技术经济分析。我们发现，积极采用电动汽车以及将电动汽车用于储电可以比仅部署光伏和电池或仅允许电动汽车充电而大大降低成本，从而帮助屋顶光伏发电在城市中普及。一氧化碳₂如果当前的整个车队都被电动汽车取代，则城市车辆和电力使用的排放量可减少60–74％，同时到2030年还可将能源成本降低22–37％。 + EV”系统（称为“ Solar-EV city”）。我们探索如何通过点对点（P2P）电力交易/区块链技术在京都实现它，最初是在社区范围以智能微电网的形式发展，然后逐渐扩展/融合到整个城市。对于向分散型电力系统的过渡，公民的决策过程是克服社会，制度和监管障碍的关键之一。