Tai'an in East China's Shandong province has completed a rooftop photovoltaic project at its municipal government center, turning the office complex into the province's first certified "zero-carbon" government office and the first in China to participate in the spot electricity market.

The neatly arranged photovoltaic panels on the rooftop of Tai'an's municipal government center in Shandong province. [Photo/Dazhong News]

The project, which went into operation on July 22, installed 2,497 solar panels with a total capacity of 1.6 megawatts on the rooftops. It generates about 2 million kilowatt-hours of clean electricity annually, with green power self-sufficiency exceeding 98 percent and grid electricity consumption cut by nearly 30 percent.

An intelligent microgrid enables power sharing among buildings. Surplus solar power during midday is stored in energy storage facilities and released during peak hours, while excess electricity can be sold on the spot market. The project will save 1.17 million yuan (around $172,817) in electricity costs and reduce carbon dioxide emissions by more than 1,900 metric tonnes per year.

Receiving 16 million yuan in private investment, the project integrates energy-saving retrofits, "source-grid-load-storage" systems, and a smart energy management platform. A solid-state transformer, co-developed by local firm Taikai Group and Tsinghua University, serves as the energy hub enabling inter-building power exchange and reducing energy loss by 10 percent.

"The municipal center has transformed from a pure electricity consumer into a participant in the urban energy system," said director Luo Guangrong from Taikai Group.