Combined solar power and storage as cost-competitive and grid-compatible supply for China’s future carbon-neutral electricity system

TLDR

China, the world’s largest CO₂ emitter, must decarbonize its energy system, making technically feasible, cost‑competitive, and grid‑compatible solar PV a critical component for meeting global 1.5 °C targets. This study develops an integrated model to project China’s spatiotemporal PV technology‑economic‑grid potentials from 2020 to 2060 under continued cost degression. The model incorporates spatial technical constraints, current economic parameters, and dynamic hourly grid interactions, and shows that coupling PV with storage yields cost‑competitive, grid‑compatible electricity. Results indicate PV potential will rise from 99.2 PWh to 146.1 PWh, average prices fall from 4.9 to 0.4 cents/kWh, price parity with coal is reached nationwide by 2023, and PV‑storage systems could supply 7.2 PWh (43.2 % of demand) at <2.5 cents/kWh by 2060, marking a pivotal transition point.

Abstract

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.