Xi Lu, Shi Chen, Chris Nielsen, Michael McElroy, Gang He, Shaohui Zhang, Kebin He, Xiu Yang, Fang Zhang, and Jiming Hao. 2023. “
Deploying solar photovoltaic energy first in carbon-intensive regions brings gigatons more carbon mitigation by 2060.” Communications Earth & Environment, 4, 369.
Publisher's VersionAbstractThe global surge in solar photovoltaic (PV) power has featured spatial specialization from manufacturing to installation along its industrial chain. Yet how to improve PV climate benefits are under-investigated. Here we explore the evolution of net greenhouse gas (GHG) mitigation of PV industry from 2009–2060 with a spatialized-dynamic life-cycle-analysis. Results suggest a net GHG mitigation of 1.29 Gt CO2-equivalent from 2009–2019, achieved by 1.97 Gt of mitigation from installation minus 0.68 Gt of emissions from manufacturing. The highest net GHG mitigation among future manufacturing-installation-scenarios to meet 40% global power demand in 2060 is as high as 204.7 Gt from 2020–2060, featuring manufacturing concentrated in Europe and North America and prioritized PV installations in carbon-intensive nations. This represents 97.5 Gt more net mitigation than the worst-case scenario, equivalent to 1.9 times 2020 global GHG emissions. The results call for strategic international coordination of PV industrial chain to increase GHG net mitigation.
Yang Zhao, Ziyue Jiang, Xinyu Chen, Peng Liu, Tianduo Peng, and Zhan Shu. 2023. “
Toward environmental sustainability: data-driven analysis of energy use patterns and load profiles for urban electric vehicle fleets.” Energy, 285, 15 Dec 2023, Pp. 129465.
Publisher's VersionAbstractThe scale-up of urban electric vehicle (EV) fleets, driven by environmental benefits, is resulting in surging aggregate energy demands that may reshape a city's power supply. This paper establishes an integrated data-driven assessment model for investigating the energy use (kWh) patterns and charging load (kW) profiles of urban-scale EV fleets. To this end, urban EV operating and operational datasets are linked with climate data and vehicle specifications. Four vehicle fleet types are distinguished: private, taxi, rental, and business fleets. Statistical models regarding distribution analysis, spectrum analysis, and identical distribution tests are employed to analyze the patterns of driving distances, energy consumption, and shares of active charging EVs. The minute-level changes in charging EV numbers and aggregate charging power are examined to reflect the grid load impact. The results show that private light-duty EVs in Beijing consume an average of 9.1 kWh/day, with more charging activities on Fridays. The primary load peaks of light-duty EVs in Beijing usually occur between 11 p.m. and 1 a.m., attributable chiefly to the private fleet's midnight peak load estimated at 28 % of the total daily charging private EV count multiplied by 5.5 kW/EV. Secondary peaks occur between 8 a.m. and 10 a.m. on weekdays for private fleets, and at 4 p.m. for public fleets. Our work can be extensively used for analyses on transport emissions, urban power supply, infrastructure build-ups, and policymaking.
Xinyang Guo, Xinyu Chen, Xia Chen, Peter Sherman, Jinyu Wen, and Michael McElroy. 2023. “
Grid integration feasibility and investment planning of offshore wind power under carbon-neutral transition in China.” Nature Communications, 14, 2447.
Publisher's VersionAbstractOffshore wind power, with accelerated declining levelized costs, is emerging as a critical building-block to fully decarbonize the world’s largest CO2 emitter, China. However, system integration barriers as well as system balancing costs have not been quantified yet. Here we develop a bottom-up model to test the grid accommodation capabilities and design the optimal investment plans for offshore wind power considering resource distributions, hourly power system simulations, and transmission/storage/hydrogen investments. Results indicate that grid integration barriers exist currently at the provincial level. For 2030, optimized offshore wind investment levels should be doubled compared with current government plans, and provincial allocations should be significantly improved considering both resource quality and grid conditions. For 2050, offshore wind capacity in China could reach as high as 1500 GW, prompting a paradigm shift in national transmission structure, favoring long-term storage in the energy portfolio, enabling green hydrogen production in coastal demand centers, resulting in the world’s largest wind power market.
Yu Fu, Haiyang Lin, Biao Feng, Cuiping Ma, Qie Sun, and Ronald Wennersten. 2023. “
Off-design characteristics of energy conversion equipment in integrated energy systems.” Journal of Cleaner Production, 407, 25 June 2023, Pp. 136941.
Publisher's VersionAbstract
With the increasing penetration of variable renewable energy, integrated energy systems (IES) have become increasingly complex. Unfortunately, the widely used constant efficiency model is too simplified to reflect actual operating conditions. Therefore, this study investigated the effects of off-design characteristics on the operation and configuration of integrated energy systems, both singly and collectively. To this aim, a two-stage optimization framework was applied to optimize the operation and configuration of IES. The off-design characteristics include the electric-thermal correlation of gas turbines (GTs), the load rate-efficiency correlation of gas boilers (GBs) and absorption chillers (ACs), and the temperature-efficiency correlation of heat pumps (HPs) and electric chillers (ECs).
When off-design characteristics are considered, the optimal capacities of the energy conversion equipment tend to increase and system costs would increase. For all system equipment, the capacity of the EC increases by 515.4% and the system cost increases by 7.3%. Regarding system operation, the effects of off-design characteristics on the operation of the GT and AC are most significant for all energy conversion equipment. The electric energy storage (EES) and the thermal energy storage (TES) help to reduce the capacity of the GT and system cost. When off-design characteristics are considered, their effects are magnified.