Peter Sherman, Haiyang Lin, and Michael B. McElroy. 2022. “Projected global demand for air conditioning associated with extreme heat and implications for electricity grids in poorer countries.” Energy and Buildings. Publisher's VersionAbstract

Human-induced climate change will increase surface temperatures globally over the next several decades. Climate models project that global mean surface temperature could increase by over 2˚C by 2050 relative to the preindustrial period, with even greater changes at the regional level. These temperature changes have clear and pertinent implications for extremes, and consequentially, heat-induced health issues for people living in particularly hot climates. Here, we study future projections in the demand for AC globally in the 2050s associated with extreme heat events. To do this, we employ an ensemble of CMIP6 models under high and low emissions scenarios. We find that the increasing frequency of extreme temperatures will cause a significant portion of the global population to be exposed to conditions that require cooling. This issue will be especially pervasive in poor countries such as India and Indonesia, which at present lack the AC units required to handle rapidly growing populations and increased frequencies of extreme temperatures. The electricity needed for cooling in these countries could reach as high as 75% of the current total annual electricity demand, which could place serious strain on the electricity grid infrastructure during peak cooling hours. We conclude that demand for cooling in the future will pose a significant challenge for poorer countries whose people will require AC units to handle extreme temperatures. In some countries, the grid infrastructure is insufficient at present to meet projected AC demands, and this need must be considered in future power systems planning.

Shaojie Song, Haiyang Lin, Peter Sherman, Xi Yang, Chris P. Nielsen, Xinyu Chen, and Michael B. McElroy. 2021. “Production of hydrogen from offshore wind in China and cost-competitive supply to Japan.” Nature Communications, 12, 2021, Pp. 6953. Publisher's VersionAbstract
The Japanese government has announced a commitment to net-zero greenhouse gas emissions by 2050. It envisages an important role for hydrogen in the nation’s future energy economy. This paper explores the possibility that a significant source for this hydrogen could be produced by electrolysis fueled by power generated from offshore wind in China. Hydrogen could be delivered to Japan either as liquid, or bound to a chemical carrier such as toluene, or as a component of ammonia. The paper presents an analysis of factors determining the ultimate cost for this hydrogen, including expenses for production, storage, conversion, transport, and treatment at the destination. It concludes that the Chinese source could be delivered at a volume and cost consistent with Japan’s idealized future projections.
Xi Lu, Chris P. Nielsen, Chongyu Zhang, Jiacong Li, Xu He, Ye Wu, Shuxiao Wang, Feng Song, Chu Wei, Kebin He, Michael P. McElroy, and Jiming Hao. 2021. “Combined solar power and storage as cost-competitive and grid-compatible supply for China’s future carbon-neutral electricity system.” Proceedings of the National Academy of Sciences, 118, October, Pp. 42. Publisher's VersionAbstract
As the world’s largest CO2 emitter, China’s ability to decarbonize its energy system strongly affects the prospect of achieving the 1.5 °C limit in global, average surface-temperature rise. Understanding technically feasible, cost-competitive, and grid-compatible solar photovoltaic (PV) power potentials spatiotemporally is critical for China’s future energy pathway. This study develops an integrated model to evaluate the spatiotemporal evolution of the technology-economic-grid PV potentials in China during 2020 to 2060 under the assumption of continued cost degression in line with the trends of the past decade. The model considers the spatialized technical constraints, up-to-date economic parameters, and dynamic hourly interactions with the power grid. In contrast to the PV production of 0.26 PWh in 2020, results suggest that China’s technical potential will increase from 99.2 PWh in 2020 to 146.1 PWh in 2060 along with technical advances, and the national average power price could decrease from 4.9 to 0.4 US cents/kWh during the same period. About 78.6% (79.7 PWh) of China’s technical potential will realize price parity to coal-fired power in 2021, with price parity achieved nationwide by 2023. The cost advantage of solar PV allows for coupling with storage to generate cost-competitive and grid-compatible electricity. The combined systems potentially could supply 7.2 PWh of grid-compatible electricity in 2060 to meet 43.2% of the country’s electricity demand at a price below 2.5 US cents/kWh. The findings highlight a crucial energy transition point, not only for China but for other countries, at which combined solar power and storage systems become a cheaper alternative to coal-fired electricity and a more grid-compatible option.
Lu et al. is the cover article of this October issue of PNAS. Read the Research Brief.
Zhenyu Zhuo, Ershun Du, Ning Zhang, Chris Nielsen, Xi Lu, Jinyu Xiao, Jiawei Wu, and Chongqing Kang. 2022. “Cost Increase in the Electricity Supply to Achieve Carbon Neutrality in China.” Nature Communications, 13. Publisher's VersionAbstract
The Chinese government has set long-term carbon neutrality and renewable energy (RE) development goals for the power sector. Despite a precipitous decline in the costs of RE technologies, the external costs of renewable intermittency and the massive investments in new RE capacities would increase electricity costs. Here, we develop a power system expansion model to comprehensively evaluate changes in the electricity supply costs over a 30-year transition to carbon neutrality. RE supply curves, operating security constraints, and the characteristics of various generation units are modelled in detail to assess the cost variations accurately. According to our results, approximately 5.8 TW of wind and solar photovoltaic capacity would be required to achieve carbon neutrality in the power system by 2050. The electricity supply costs would increase by 9.6 CNY¢/kWh. The major cost shift would result from the substantial investments in RE capacities, flexible generation resources, and network expansion.
Shaojie Song, Haiyang Lin, Peter Sherman, Xi Yang, Shi Chen, Xi Lu, Tianguang Lu, Xinyu Chen, and Michael B. McElroy. 2022. “Decarbonization of the Indian economy: 2050 prospects for wind, solar, and green hydrogen.” iScience, 25, 6, Pp. 104399. Publisher's VersionAbstract
The paper explores options for a 2050 carbon free energy future for India. Onshore wind and solar sources are projected as the dominant primary contributions to this objective. The analysis envisages an important role for so-called green hydrogen produced by electrolysis fueled by these carbon free energy sources. This hydrogen source can be used to accommodate for the intrinsic variability of wind and solar complementing opportunities for storage of power by batteries and pumped hydro. The green source of hydrogen can be used also to supplant current industrial uses of gray hydrogen produced in the Indian context largely from natural gas with important related emissions of CO2. The paper explores further options for use of green hydrogen to lower emissions from otherwise difficult to abate sectors of both industry and transport. The analysis is applied to identify the least cost options to meet India’s zero carbon future.
Ziwen Ruan, Xi Lu, Shuxiao Wang, Jia Xing, Wei Wang, Dan Chen, Chris P. Nielsen, Yong Luo, Kebin He, and Jiming Hao. 2022. “Impacts of large-scale deployment of mountainous wind farms on wintertime regional air quality in the Beijing-Tian-Hebei area.” Atmospheric Environment, 278, June, Pp. 119074. Publisher's VersionAbstract
The development of wind power plays an essential role in achieving China's carbon neutrality goals and air quality standards. A large number of studies have addressed the benefits of substituting fossil fuels with wind power on climate and air quality (defined as indirect impact) by macro-scale methodology. In recent years, more and more researchers have discussed its impacts on the general atmospheric circulation and air pollution dispersion (defined as direct impact) by parameterizing wind energy extraction in meso-micro scale models. However, the comprehensive investigation (considering both direct and indirect impacts) of the utilization of wind power on atmosphere environmental impacts remains vacant. Our study first evaluated both the direct and indirect impacts of wind power on air quality through an integrated methodological framework by using WRF-CMAQ system. The present analysis took wind farms located in Zhangjiakou to explore their impacts on air quality in winter, particularly over the downwind Beijing municipal area in the North China Plain. Results indicated that the deployment of wind power leads to spatially mixed direct impacts on PM2.5 concentrations in Beijing with a monthly net increase of 0.067 μg/m3 (0.08%) relative to the regional average. Contrarily, the substitution of coal-burning with wind power in rural household heating would result in notable indirect benefits to monthly PM2.5 concentrations in Beijing, specifically, reducing emissions of CO2 and conventional air pollutants by 64% in rural heating sector. The combined impacts of wind power displayed regional differences: in the wintertime (January), Zhangjiakou PM2.5 concentrations increased (+0.147 μg/m3) whereas, decreases are achieved (−5.642 μg/m3) in Beijing. Therefore, to support the large-scale deployment of wind power, future energy policies should take comprehensive account of the diverse environmental impacts, including both the indirect benefits of fossil energy substitution and the potential direct atmospheric effects on regional air quality.


March 8, 2022


王峥,博士。 来自北京大学,对能源的兴趣是他童年的一部分。 他成长于中国陕西延安,东汉时期(公元32年左右)有“水能烧(油)”的记载,中国第一口油井于1905年在郑氏国小修筑。 “在成长过程中,我与燃料和能源有着密切的接触,这让我对能源在工业发展和社会经济进步中的作用,以及能源作为当地政府主要收入来源之一的作用有了一定的认识, ”铮解释道。 “这让我对能源在社会经济中的真正作用感到好奇。” 随着家乡向风能和太阳能等可再生能源转型,铮亲眼目睹了能源在社会中的角色转变。 他计划在哈佛继续他的可再生能源研究。 他首先计划计算中国陆上和海上风电在不同时间(2030年、2060年)不同场景(如并网、多样化储能)下的容量潜力。 他将利用这些数据探索不同海拔高度风电的效率和经济成本,并比较中国风电和光伏的成本。 铮还计划将气候变化模型和陆面模型模拟结合起来,考虑计算不同地区风-光-储系统长期储能的容量需求。



对于香港大学博士研究生向晨来说,她有过一次前往危地马拉安提瓜的环境志愿服务之旅,在那里她从事水过滤工作,从而开启了她在环境治理方面的职业生涯。 “...

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Peter Sherman

介绍哈佛中国项目的新进博士后: Peter Sherman

February 28, 2022

Peter Sherman

Peter Sherman, 哈佛中国项目博士后,他最近获得了博士学位。他毕业于哈佛大学地球与行星科学系。他说,回顾他在哈佛的研究生时光,他感恩对本科生和当地高中生的指导。“让年轻人有机会了解(偶尔会遇到困难!)研究帮助我以我开始指导时没有想到的方式完善了我的教学和科学观点,”彼得解释道。 “从这些经验中,我学会了如何更好地综合和呈现研究,从而更容易‘坚持’人们学习气候变化科学。” 彼得对能源和气候变化研究的热情转化为他作为哈佛中国项目博士后研究员的新角色,他正在努力帮助了解气候危机的范围并提供可以实施以缓解这些问题的解决方案。 彼得的重点是区域气候变化如何影响人们,以及我们如何通过使我们的能源系统脱碳来减少一些主要后果——其中大部分是建立在他的博士学位基础上的研究。“我们特别关注电力部门以及一些难以减排的部门的脱碳方法,并考虑了一些项目,旨在跟进我们过去对印度电力部门和绿色能源所做的研究,”彼得说。“我还对关注气候和能源交叉的项目感兴趣,目前正在开展一个较小的项目,研究气候变化对未来空调需求的影响(以及由此对电网造成的影响)。 ” 彼得期待继续与哈佛中国项目的同事合作,并指出“整个团队非常棒,因为有来自各个领域的专家,从气候到大气化学再到能源系统规划。...

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Haiyang Lin

介绍哈佛中国项目的新进博士后: 蔺海洋

March 1, 2022


蔺海洋,哈佛中国项目博士后,最近获得博士学位。他毕业于山东大学动力工程与工程热物理专业,成长于山东省寿光市。寿光素有蔬菜之乡的美誉,海洋从小就见证了各种果蔬从种植到成熟的过程,海洋称这是人类利用太阳能最古老、最自然的能源过程。因此,对于他来说,他将在数学和物理方面的天赋与他目前博士后研究的能源领域兴趣结合起来是很自然的。 过去几年,海洋一直致力于综合能源系统模拟和优化,研究能源供需特征。“我在这里的工作旨在通过结合技术经济模型来优化低碳能源系统的设计和运营,从而解决可再生能源、生物质能源和绿色氢应用的经济可行性和脱碳潜力,”海洋解释道。 他正在研究中国、日本和印度的脱碳战略,其中氢被认为在促进向未来深度脱碳能源系统过渡方面发挥关键作用,并有助于提高可再生能源在电力系统中的渗透率。 随着海洋继续他作为能源研究员的工作,他非常感谢哈佛-中国项目的跨学科性质。 “综合能源系统研究需要来自多个学科的投入,例如电力、经济学、气候、交通等,”他解释道。 “在这个小组中,我可以接触到这些专家,可以轻松地填补我学习的空白。 这么多具有不同专业知识的人正朝着同一个目标努力,这是非常了不起的。