A major milestone in renewable energy was reached on August 12th at 10 AM when the Ningbo Qianwan New District's Ningbo Science Middle School 1,038 kW distributed solar project was connected to the grid. This connection pushed the city's total distributed solar capacity past the 10 GW mark, making Ningbo the first city in China to achieve this scale of distributed photovoltaic installations.
Unlike the traditional image of massive, centralized solar farms in the northwestern Gobi deserts, this industrial powerhouse has forged a unique path. Its 10 GW of distributed solar capacity is entirely rooted in "fragmented" spaces, including industrial parks, public buildings, and residential rooftops. Notably, industrial parks account for 84% of this capacity, with vast expanses of idle factory roofs transformed into small-scale power plants.
Currently, one out of every ten kilowatt-hours of electricity used for production and daily life in Ningbo comes from solar energy. Based on an equivalent full-load operation of 1,000 hours per year, these distributed solar installations can generate 10 billion kilowatt-hours of clean electricity annually. This production is equivalent to reducing carbon dioxide emissions by approximately 5 million tons, or the carbon-absorbing capacity of about 120 million trees.
While this massive deployment of "fragmented" solar power strengthens the security of the city's power grid, especially for a city that has ranked first in the province for total electricity consumption for six consecutive years, it also presents a "sweet burden." The inherently intermittent nature of solar power means that with alternating sunshine and clouds, short-term output can fluctuate by up to 3 GW. This level of volatility is comparable to starting or stopping a large thermal power plant, leading to secondary challenges such as reverse overload on the distribution network, a mismatch between supply and demand during peak and off-peak times, and complex energy settlement calculations for industrial parks.
Facing the unprecedented speed and scale at which a vast number of small, distributed solar installations are flooding the power grid, State Grid Ningbo Electric Power Supply Company is tackling these new energy challenges from both a technical and service-oriented perspective.
On the technical side, the company has leveraged the Key Laboratory for Digital-Physical Hybrid Simulation of New Power Systems to build a county-level power grid full-element planning simulation platform. This platform allows for comprehensive pre-connection simulations before a new solar project is even integrated. "It's like a 'sand table'. You can simulate where to connect distributed solar, how to connect it, and what the impact on the grid will be, all in a virtual environment first. This helps find the optimal solution to ensure green electricity can be generated and transmitted," explained Feng Yibin, Director of the Technology Innovation Office at the company's Economic and Technological Research Institute. The platform boasts "full-element, full-voltage, full-link, and full-area" simulation capabilities, using dedicated computing servers to achieve 50-microsecond-level high-precision calculations, equivalent to running 20,000 grid state simulations per second. More importantly, it can "preview" various extreme scenarios, such as low load during the Spring Festival combined with high solar generation, allowing for proactive deployment and adjustments to prevent potential overload and overvoltage issues.
After completing this upfront planning, the next challenge is to make the randomness and volatility of solar power controllable. Relying on its "Main Distribution Marketing" dispatch decision center, the company has broken down the long-standing data silos between the main transmission grid, distribution network, and marketing operations. The grid's operational logic has shifted from singularly controlling the grid to coordinating all types of adjustable energy resources across society. The platform works with the meteorological department to build a dedicated power-weather forecasting model, achieving a 96% accuracy rate for new energy output predictions. City-wide energy storage, microgrids, and flexible industrial and commercial loads are all connected to a municipal-level virtual power plant, aggregating a million kilowatts of adjustable resources. When a cloud passes and causes a sudden drop in generation, the system can compensate with stored energy and adjust loads within minutes, effectively smoothing out the fluctuations from new energy sources.
However, solving these issues does not automatically mean that all this clean energy can flow unimpeded through the distribution lines to every household and continuously lower electricity costs. During specific periods, such as when solar generation is high on a sunny day or when businesses are shut down and load is low, the power generated in a local area can far exceed its demand. This surplus clean energy, which cannot be consumed locally, flows back from the user side to the grid, causing voltage rise and short-term line overload. In severe cases, this can damage electrical equipment or limit the normal output of the solar installations, leading to wasted green energy and curtailment.
These subtle and hard-to-detect grid flow anomalies can now be captured accurately and managed efficiently around the clock with the country's first practical "Distributed Solar Operation Monitoring Application." On the system interface, red and green lines intertwine, representing different power flows. Green indicates the forward flow of power from the grid to the user, while red signifies the reverse flow of surplus solar power. With this system, a grid dispatcher can instantly see the power flow direction on every line. If an anomaly is detected, the dispatcher can use the distribution automation system to remotely control smart switches on the distribution lines, quickly redirecting power flow. This allows for precise routing of local surplus solar power to areas with sufficient load, dynamically balancing the grid's power supply and demand, and enhancing local solar energy consumption.
As technical challenges are being addressed one by one, service-side innovations are also being upgraded simultaneously. On the service front, State Grid Ningbo Electric Power Supply Company has launched an "Electricity-Energy-Carbon" integrated service model for industrial parks. This model combines the three processes of "power connection, energy efficiency, and carbon management" into a comprehensive energy service system covering the entire lifecycle of an enterprise, from "planning and construction to operation." Previously, park enterprises had to contact multiple agencies for services like power connection, energy efficiency diagnosis, energy-saving retrofits, carbon footprint accounting, and green electricity certificates, a process that was complicated and time-consuming. Now, a single team handles everything, enabling energy facilities to be operational at the same time a factory is built, offering a "plug-and-play, instant-use" experience.
When solar panels are installed on the rooftops of industrial parks, they often bring a confusing financial picture for the enterprises. "The electricity pricing policy is complex and ever-changing. We can only see the total meter reading; we don't know who used the green electricity we generated or how the savings are distributed," said Jin Cheng, manager of the Fengzheng Intelligent Manufacturing Park, a sentiment shared by many businesses. To address this, the "Sunshine Manager" digital settlement platform was created. By installing smart meters to replace manual meter reading, the platform enables sub-metering of electricity data and online centralized collection, allowing users to monitor real-time details like total meter power, sub-meter power, electricity prices, and charges. Using this online data, the platform is also connected with banks to handle the entire process of metering, settlement, and automatic invoicing online, compressing the solar park settlement cycle from 45 days to just 3 days. To date, the platform has covered over 18,600 enterprises and parks across the province, completing a total of 14.062 billion yuan in fund settlements.
As the first city in China for distributed solar power, reaching 10 GW is a landmark milestone in Ningbo's green transformation and a brand new starting point. Looking ahead to the "15th Five-Year Plan" for low-carbon energy development, Ningbo plans to shift its solar development focus from scale growth to improving quality and efficiency. The city will continuously innovate diverse models to broaden the pathways for green electricity consumption, deploy cutting-edge application scenarios like energy storage, hydrogen, and computing power, explore market-based trading mechanisms, and deepen the development of multi-format green electricity coupling. The goal is to create a "Ningbo Model" for achieving the national "dual carbon" targets.