China has built offshore wind faster than any other country. By the end of 2025, its grid-connected offshore wind capacity had reached 47 GW, roughly half the global total. But one question keeps coming up in discussions about its future: if offshore wind is still more expensive per kilowatt-hour than solar or onshore wind, why should China build so much more of it? That question motivated our recent study in Communications Earth & Environment. Rather than looking only at the cost of generating electricity, we asked what offshore wind might be worth once we also account for where the electricity is produced, where investment and jobs occur, how much electricity provinces need to import, and what additional infrastructure the power system requires.

👉 Read the paper | Data & Code | Communications Earth & Environment

Our results suggest that these broader system effects can substantially change the way we think about the value of offshore wind in China. In a scenario with much faster deployment, China’s coastal provinces could become far more energy self-sufficient, attract more local investment and employment, and reduce their dependence on long-distance transmission and storage. The overall increase in national power-system costs remains relatively small, around 2% compared with a pathway without a long-term offshore wind target.

For me, the broader lesson is that offshore wind should not be evaluated only as another low-carbon generation technology. Its location matters.

Why location matters in China’s power system

China’s power resources and electricity demand are geographically mismatched. Many of the country’s best onshore wind and solar resources are located in the north and northwest, while some of the largest concentrations of electricity demand are along the eastern and southern coast. As a result, coastal provinces depend heavily on electricity generated hundreds or even thousands of kilometres away.

Offshore wind is different because it places a large renewable resource directly next to these demand centres.

To understand what that could mean for the power system, we used GridPath, an open-source capacity-expansion and dispatch model, to represent China as 32 interconnected provincial regions and simulate the power system from 2025 to 2050. We compared three pathways for offshore wind deployment: a baseline reaching 214 GW by 2050, a moderate pathway reaching 250 GW, and an accelerated pathway reaching 1,000 GW. We also tested the results across a wide range of assumptions about technology costs, electricity demand, carbon constraints, transmission costs and policy targets.

The 1,000 GW scenario is not intended as a forecast. Instead, it allows us to ask what China’s power system might look like if offshore wind were developed at a much larger scale.

Coastal provinces could become far more self-sufficient

One of the clearest results is the change in the geography of electricity supply. In the accelerated offshore wind scenario, the ten coastal provinces we studied move collectively from importing 813 TWh of electricity in 2050 to exporting 88 TWh.

This is a major structural change. Provinces that have traditionally been treated primarily as electricity consumers begin to become important electricity suppliers themselves. Average energy self-sufficiency across the coastal region rises by 26 percentage points relative to the baseline.

The effect is especially striking in some provinces. Zhejiang, for example, becomes a large net exporter of electricity, while offshore wind grows into one of the dominant sources of power in provinces such as Jiangsu and Guangdong.

This finding matters because energy security at the provincial level is an important concern in China. A coastal province may care not only about how cheaply electricity can be produced somewhere in the country, but also about how dependent it is on distant generation and interprovincial transmission.

From that perspective, offshore wind offers something that inland wind and solar cannot: large-scale clean generation located close to the centres of demand.

Maps and charts showing net electricity transmission by province under the Base, MOSW, and AOSW scenarios in 2050
Figure 1: Under higher offshore wind deployment, several coastal provinces transition from major electricity importers to exporters, and average coastal energy self-sufficiency rises above 100%. Base: baseline scenario; MOSW: moderate offshore wind; AOSW: accelerated offshore wind. Source: Peng et al., Communications Earth & Environment, 2026.

Investment and jobs also shift toward the coast

A large offshore wind build-out would also reshape where power-sector investment takes place. In our accelerated scenario, cumulative investment in coastal power generation reaches roughly $2.6 trillion between 2025 and 2050, about 15% higher than in the baseline.

Power-sector employment in the ten coastal provinces also increases by about 16%, from 41.7 million to 48.3 million job-years over the study period. These jobs include equipment manufacturing, construction and installation, and operations and maintenance.

But this is not simply an additional benefit for everyone.

Some of these economic activities shift geographically. Inland investment falls by about 6%, and regions that currently export large amounts of electricity to the east would supply less of it. Inner Mongolia, for example, sees its electricity exports decline by 318 TWh in the accelerated offshore wind scenario.

I think this redistribution is important to acknowledge. Offshore wind can create substantial economic opportunities for coastal provinces, but those gains can also change existing regional relationships within China’s power system. That means the transition is not only a question of how much clean energy gets built. It is also about where investment takes place and which regions benefit from it.

Charts of cumulative investment by coastal province, inland versus coastal investment, and power sector jobs from 2025 to 2050
Figure 2: Faster offshore wind deployment shifts investment and employment toward China's coastal provinces while reducing reliance on inland electricity production. Source: Peng et al., Communications Earth & Environment, 2026.

One of the most surprising results: less transmission

One result surprised us in particular. Generating more electricity close to coastal demand reduces the need for long-distance transmission. Total transmission capacity required in 2050 is 13% lower in the accelerated offshore wind scenario than in the baseline.

This happens because China’s current grid structure is designed largely around transporting electricity from resource-rich western and northern regions toward eastern demand centres. If coastal provinces generate more of their own electricity, some of that long-distance transfer becomes unnecessary.

We also find that offshore wind reduces pressure on energy storage. Because offshore wind has a different and generally steadier generation profile than solar, batteries and pumped hydro do not have to work as hard to balance the system. Nationally, battery discharge falls by 54 TWh and pumped-hydro discharge by 29 TWh in the accelerated case.

These avoided transmission and storage requirements are part of the system value of offshore wind, but they are easy to miss when technologies are compared only using levelised generation costs.

How much does this cost?

The obvious question is whether these benefits require a much more expensive power system. In our modelling, the answer is: not very much more.

Reaching 1,000 GW of offshore wind by 2050 raises total power-system costs by about 1.9% compared with a pathway without a long-term offshore wind target. We also tested a wide range of offshore grid-connection costs based on empirical project data from China, Europe and the United States. Across those assumptions, the total system-cost increase ranges from about 1.4% to 2.5%.

This does not mean offshore wind is cheap in every sense. It remains more capital-intensive than many alternatives. But the comparison looks quite different once we evaluate the entire system rather than just the cost of electricity at the generator.

What I think the results imply

Three implications stand out to me.

First, long-term policy direction matters. In our sensitivity analysis, the ambition of the offshore wind target is the single largest determinant of how much offshore wind ultimately gets built. This suggests that clarity beyond 2030 may matter as much as, or more than, short-term support mechanisms.

Second, transmission planning and generation planning should be considered together. If offshore wind substantially reduces coastal dependence on imported electricity, some long-distance transmission investments may no longer be needed in the same form or at the same scale.

Third, electricity-market reform becomes increasingly important. If coastal provinces eventually build more offshore wind than they need for their own consumption, they must be able to sell that electricity efficiently across provincial borders.

Demand growth also matters. In our sensitivity analysis, electricity demand is the second-largest driver of offshore wind deployment after policy ambition. A high-demand future results in 86% more offshore wind capacity than a low-demand future. As electrification and new industrial loads continue to expand along China’s coast, the value of having a large renewable resource located directly offshore is likely to grow.

A broader way to think about offshore wind

When we started this project, the discussion around offshore wind often seemed to come back to one comparison: how much does a kilowatt-hour of offshore wind cost relative to solar or onshore wind?

Our results suggest that this comparison is incomplete. For China’s coastal provinces, offshore wind can also change where electricity is produced, reduce dependence on distant power imports, shift investment and employment, and lower the need for some transmission and storage infrastructure.

Those effects do not make offshore wind automatically preferable to every alternative. But they do suggest that its value cannot be understood from generation cost alone. For me, that is the most important takeaway from the study: energy technologies are not valuable only because of what they generate, but also because of where they are built and how they reshape the wider energy system.

This post is based on our study published in Communications Earth & Environment. Data and code are available on Zenodo.