盐城的绿电专线：海上风光怎么直供零碳园区Yancheng's Green Power Dedicated Line: How Offshore Wind Directly Supplies Zero-Carbon Parks

Minghui

At a substation in Dafeng Port, Yancheng, there is a busbar that has been designated separately. It only connects to green electricity and does not connect to any other power sources; every kilowatt-hour it supplies can be traced to which part of the sea, which row of wind turbines, and which photovoltaic panel it comes from. This 10-kilovolt line, called the "Haiyun Line," is one of the earlier green electricity dedicated lines in China and also represents an attempt by this coastal city to turn offshore wind and solar resources into industrial competitiveness.

A City's Resource Base of Wind and Solar

Yancheng is located in the central coastal area of Jiangsu, with a long coastline and vast tidal flats; both wind and land resources are considered relatively scarce conditions among eastern cities. According to data disclosed by the local government, the connected capacity of offshore wind power in Yancheng has reached 7.04 million kilowatts, ranking among the top in the country; the installed capacity of renewable energy power generation exceeds 26 million kilowatts, with an annual power generation exceeding 42 billion kilowatt-hours, accounting for a significant portion of the city's electricity consumption. At the same time, Yancheng is also promoting a 1-million-kilowatt-class offshore photovoltaic demonstration project and the competitive allocation of subsequent large-scale offshore photovoltaic resources, with planned offshore photovoltaic capacity reaching several million kilowatts.

Behind these numbers is a complete industrial chain. Wind power complete machines, blades, towers, submarine cables, construction and operation maintenance—Yancheng has basically formed local support; in the photovoltaic sector, there is also a layout for solar cells, modules, brackets, and frames. The existence of the industrial chain allows resource development and equipment manufacturing to form a cycle: local projects place orders with local companies, and local companies help local projects reduce costs.

However, wind and solar resources have a natural flaw: power generation is not synchronized with electricity consumption. Wind power output is high at night and low during the day, while photovoltaics are the opposite; industrial load is continuous. Yancheng's solution is not simply to build energy storage, but to make “green electricity” a traceable commodity—allowing electricity-consuming enterprises to prove that the electricity they use is truly green, which is increasingly important in export-oriented industries.

How physical traceability is achieved

The conventional method for green electricity trading is green certificates, which are attribute certifications; Yancheng Dafeng Port Zero Carbon Industrial Park takes a different path: physical traceability.

The specific approach is to renovate substations. State Grid Yancheng Electric Power Company carried out an intelligent transformation of the 110 kV Jincheng Substation in Dafeng District, setting up an independent busbar for the park. Except for park enterprises, all other intervals are connected only to green electricity. Through a physically isolated design, the power grid flow is clearly distinguishable, and the path of green electricity from production to consumption is completely independent, allowing each kilowatt-hour of electricity to be traced back to a specific generation unit. Based on this, the park established the country's first 10 kV 'green electricity dedicated line,' the Haiyun Line, achieving direct supply of 13.76 MW centralized photovoltaic power to enterprises, providing 15 million kWh of green electricity annually. In the 1.4 square kilometer pilot zone of the zero-carbon industrial park, a 'one-to-many' green electricity direct supply scenario has been formed, where each kilowatt-hour of green electricity can be physically traced, and each ton of carbon can be tracked.

This approach has expanded from one park to three port areas. Public information shows that the State Grid Yancheng Power Supply Company has invested nearly 120 million yuan, completed busbar upgrades for three 110 kV substations, reconnected 24.5 kilometers of lines, and connected renewable energy installations totaling 174,250 kW to the three zero-carbon industrial parks of Yancheng Dafeng Port, Sheyang Port, and Binhai Port, providing 1.143 billion kWh of green electricity annually. All three parks have established a physically traceable green electricity network.

The planned area of Dafeng Port Zero-Carbon Industrial Park is 31 square kilometers, of which the 1.4-square-kilometer pilot area has fully realized direct green electricity supply. The 16.6-square-kilometer expansion area and 13-square-kilometer transformation area are focusing on the 220 kV Weihai substation and Dangui substation 'dual-core' green electricity dedicated substations, constructing a high-proportion utilization system of 'robust smart grid + integrated wind, solar, hydrogen, and storage power + green electricity traceability and certification.' The idea behind this system is clear: it does not pursue 100% physical isolation but, under the support of the larger grid, ensures that the proportion, path, and timing of green electricity are all verifiable.

How does green electricity turn into green production?

For the park, the value of green electricity is not in cheap electricity prices, but in the ability of products to go overseas. As the European Union's Carbon Border Adjustment Mechanism is gradually implemented, the accounting of the carbon footprint of exported products is becoming increasingly strict, and the proportion of green electricity used in production directly affects carbon costs. An electric bicycle company placed its production line in the Dafeng Port Zero-Carbon Industrial Park, attracted by the 'safe, reliable, and traceable pure green electricity'; the park also introduced international certification bodies to promote mutual recognition and interchange of product carbon footprint accounting, evaluation, and certification standards, allowing enterprises to obtain green certificates recognized by the international market without leaving the park.

The park's supporting Energy-Carbon Intelligent Management Center collects real-time data on enterprise electricity consumption and carbon emissions, enabling the generation of carbon inventory reports compliant with both international and domestic regulations with just a tap on the screen. Although this kind of infrastructure may seem inconspicuous, it is actually the core competitiveness of a zero-carbon park—without credible data, zero carbon is just a slogan.

Yancheng's industrial choices also extend along this line. In addition to wind power equipment and photovoltaic manufacturing, new industries sensitive to green electricity, such as green methanol, green hydrogen, and energy storage batteries, are gathering; power battery and renewable energy vehicle component companies are locating their factories in green electricity-rich areas, which not only reduces energy costs but also meets customers' supply chain carbon requirements. Green electricity has transformed from a cost factor into an investment attraction factor.

Three technological challenges

Direct supply of green electricity sounds simple, but there are three engineering hurdles to overcome.

The first is flow control. New energy output fluctuates greatly, causing voltage and frequency on the dedicated lines to easily vary; the park's load is mainly manufacturing, which is sensitive to power quality. The solution is to equip dedicated lines with energy storage and dynamic reactive power compensation—using energy storage to smooth fluctuations and reactive power compensation to maintain voltage. This is also the reason the park plans for an 'integrated wind, solar, hydrogen, and storage' system—standalone wind and solar cannot support stable industrial power supply.

The second aspect is protection setting. The operation mode of an independent bus is different from that of a traditional power grid, and the path of fault currents changes. The original relay protection settings are no longer applicable and need to be reset and functionally verified. This type of work is highly technical and has a wide impact, so it must be involved during the design phase.

The third aspect is measurement and settlement. Physical traceability requires precise measurement of the source of every current, which necessitates the installation of high-precision metering devices and data acquisition terminals, and integration with the grid's settlement system. The accuracy of measurement directly determines the credibility of green certificates and carbon reports, leaving no room for ambiguity.

Another transformation path for coastal cities

The practice in Yancheng provides a transformation idea for coastal cities: instead of simply selling resources to the grid, it is better to turn resources into local industrial advantages.

Under the traditional model, when wind and photovoltaic power is fed into the grid, cities only receive land rent and taxes, while the added value of the industrial chain stays elsewhere. The green power direct supply model links power generation and consumption in the same space, so the added value stays locally—electricity-consuming companies are attracted by green power, equipment companies gather because of projects, and production-oriented service industries such as certification, testing, and carbon management also grow along with it. This three-tier amplification of 'resources—industry—services' is more valuable than merely expanding installed capacity.

Of course, this model also has its limitations. Physical tracing requires a dedicated network structure, which is a significant investment, so it is only cost-effective in parks with sufficiently high load density and strong corporate willingness to pay; the proportion of green power direct supply is limited by the characteristics of renewable output, and being completely independent of the main grid is neither economical nor safe; park zero-carbon certification standards are still being perfected, and the pace of international mutual recognition will affect corporate enthusiasm.

The difficulty of urban energy transition has never been a lack of resources, but a lack of mechanisms to turn resources into value. Yancheng has turned a 10kV line into a carrier for institutional design: where electricity comes from, how it is delivered, who it is used, how it is proven—every step has clear answers. When green electricity can be measured, certified, and traded, offshore scenery truly becomes the city's industrial capital.

(Source: Public information from Yancheng Municipal People's Government, State Grid Jiangsu Electric Power Co., Ltd., Economic Daily investigative report, China Energy News)

[Research Supporting Institution: China Industry News Energy and Dual Carbon Research Center | China Energy Industry Development Network]