Energy Systems

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, 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.
Xinyu Chen, Yaxing Liu, Qin Wang, Jiajun Lv, Jinyu Wen, Xia Chen, Chongqing Kang, Shijie Cheng, and Michael McElroy. 2021. “Pathway toward carbon-neutral electrical systems in China by mid-century with negative CO2 abatement costs informed by high-resolution modeling.” Joule, 5, 10 (20 October), Pp. 2715-2741. Publisher's VersionAbstract
China, the largest global CO2 emitter, recently announced ambitious targets for carbon neutrality by 2060. Its technical and economic feasibility is unclear given severe renewable integration barriers. Here, we developed a cross-sector, high-resolution assessment model to quantify optimal energy structures on provincial bases for different years. Hourly power system simulations for all provinces for a full year are incorporated on the basis of comprehensive grid data to quantify the renewable balancing costs. Results indicate that the conventional strategy of employing local wind, solar, and storage to realize 80% renewable penetration by 2050 would incur a formidable decarbonization cost of $27/ton despite lower levelized costs for renewables. Coordinated deployment of renewables, ultra-high-voltage transmissions, storages, Power-to-gas and slow-charging electric vehicles can reduce this carbon abatement cost to as low as $−25/ton. Were remaining emissions removed by carbon capture and sequestration technologies, achieving carbon neutrality could be not only feasible but also cost-competitive post 2050.
Jianglong Li and Mun Sing Ho. 2024. “End-year China wind power installation rush reduces electric system reliability.” Energy Economics, 133, May 2024, Pp. 107507. Publisher's VersionAbstract
The urgent challenge posed by climate change has catalyzed global efforts to transition towards sustainable energy sources, with wind power emerging as a pivotal component. However, the rapid expansion of renewable energy sources has raised concerns about electric system reliability, given their intermittent and hard-to-forecast nature. China has provided incentives that promoted the rapid expansion of wind. However, the structure of some incentives led to the phenomenon of end-year rushes to install wind power before incentives expire. Leveraging panel data from China's provinces, we empirically estimate the impact of these installation rushes on electric reliability. We find significant adverse effects, with a one-standard-deviation increase in installation rush corresponding to a 0.767% decrease in the reliability rate and a 39.6-min increase in annual outage duration. Notably, urban areas and the northwestern grid are particularly vulnerable to the disruptions caused by year-end installation rushes. In the urban areas of the northwestern grid, we identify the potential for substantial improvements in the lower bound of the reliability rate, from 98.86% to 99.37%, or a reduction in outage duration from 11.65 h to 7.16 h. These findings show the importance of structuring incentives properly and the importance of improvements in grid infrastructure and management in the transition to a low-carbon world.
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, 268, August, Pp. 112198. 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.

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, 3172. 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.

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