IGCC Researchers Model a Pathway to a Carbon-Neutral China
Human induced climate change—driven by use of carbon-based fossil fuels and the greenhouse gases (GHGs) they produce—is inflicting immense environmental and social costs around the world. The rapid warming of the earth’s surface temperature threatens the ecosystems we depend upon for food and water, increases the frequency of extreme weather events, and may eventually render large swathes of land uninhabitable. Scientists argue that we must sharply reduce and ultimately eliminate GHG emissions, primarily carbon dioxide (CO2), to avert disaster.
That will not prove easy. The transition to climate-friendly energy requires a complete transformation of how we live, work, and move. It will also depend on the use of technologies that have yet to be invented, as well as a vast network of clean energy storage capacity and transmission infrastructure that does not currently exist.
China’s Crucial Transition
Perhaps no country better illustrates both the complexity and imperative of that energy transition than China.
Over the past three decades, China has become a global leader in manufacturing and innovation. Its economy has grown to the second largest in the world, uplifting millions of people out of poverty along the way. Owing to its vast expansion of coal-powered industrial activity, China has also become the single biggest emitter, responsible for more than 30 percent of CO2 released into the atmosphere—more than double that of the second biggest polluter, the United States, which accounts for approximately 14 percent of CO2.
Since 2009, China has announced a series of international commitments to reduce emissions and accelerate the adoption of non-fossil energies, namely wind and solar. Upon signing the Paris Agreement in 2015, China declared its intention to reach peak emissions in the first half of the century. In September 2020, President Xi Jinping built upon previous commitments by announcing China’s most ambitious goal to date: carbon neutrality and the production of at least 80 percent of the country’s energy from non-fossil sources by 2060.
The news was greeted with enthusiasm by much of the international community. Many observers rightfully noted that there is no credible path to limit rising temperatures and avoid catastrophe without decisive action by the world’s top polluter. Others reacted with skepticism, citing the sheer magnitude of change required in a comparatively brief timeframe and noting the absence of a clear roadmap for implementation.
Meanwhile, in San Diego and Beijing, a team of researchers began work on a project that could help inform how China—and other large countries, like India and the United States—navigates the difficult journey to carbon neutrality.
A Research Agenda Takes Shape
Michael Davidson is an assistant professor at UC San Diego’s School of Global Policy and Strategy and Mechanical and Aerospace Engineering Department and an affiliate researcher at the University of California Institute on Global Conflict and Cooperation (IGCC). He has been conducting research on the challenges associated with China’s renewable energy transition for more than a decade. When he began, many studies on the subject assessed very high potential from the country’s wind and solar resources by examining just two variables: the availability of each resource—wind speeds and solar radiation—and the total landmass where infrastructure could be built.
“That narrow approach often led to rosy projections that made the transition seem fairly easy. It ignored a lot of the messy complexity, like limitations in the electricity grid, the large distances between energy generation sites and cities, and the conflicts over land use that may arise over time,” says Professor Davidson.
He wanted to create a more realistic projection of how a significant scale-up of renewable energy might unfold. In 2016, he and Da Zhang, now an associate professor at Tsinghua University, created a model that estimated how much electricity China could cost-effectively source from wind by 2030. In contrast to other analyses at the time, their model incorporated constraints inherent in the country’s largely coal-powered electricity grid. They concluded that although wind energy could contribute 26 percent of China’s projected electricity demand in 2030, that figure represented a mere 10 percent of the total potential for wind-sourced electricity in the country.
“For years, China’s electricity grid was designed to be powered by coal. Integrating wind energy into that legacy system has brought lots of challenges,” notes Professor Zhang. “Maximizing wind’s potential will require targeted investment and policy interventions.”
Professors Davidson and Zhang published their findings in Nature Energy. As one of the first studies that broadened the analysis of China’s energy transition to incorporate limitations of the existing power grid, their article precipitated several studies by other academics exploring related concepts. It also attracted the attention of Professor Xi Lu, a colleague of Zhang’s at Tsinghua University, who had been collecting highly detailed data on the availability and quality of renewable energy resources across China.
“My group has focused on developing a dynamic modeling system with high spatial resolutions to map out what China’s renewable energy mix could look like in 2060 in a carbon-neutral environment. But I was increasingly attracted by the questions on how to get there and the challenges we might encounter along the way,” says Professor Lu.
In 2021, Professors Davidson, Zhang, and Lu agreed to complement the ongoing research at Tsinghua by collaborating on a study that would project, on a decade-by-decade basis, where and how many wind and solar production sites need to be built to meet China’s 2060 targets. They were especially interested in researching the constraints that would emerge over time around site availability, grid capacity, and technological limitations.
China’s Renewable Energy Pathway
At present, China sources nearly 85 percent of its energy from fossil fuels. While efforts to deploy wind and solar production sites have accelerated in recent years, they still comprise just 3 percent and 2 percent, respectively, of the country’s primary energy mix, or 8 percent and 4 percent, respectively, of electricity generation. To reach carbon neutrality by 2060, China will need to significantly expand its use of wind and solar energy.
That expansion has not been without issue. To date, China has built production sites in the country’s northern and western regions, which have an abundance of wind and sun and fewer land use issues due to the remote locales. The concentration of sites in these regions has caused issues with “curtailment,” where energy is wasted because the electricity grid is unable to accommodate all of the new energy sources. Curtailment rates have improved over the last few years as electricity demand has grown and operational changes have increased the grid’s flexibility.
But how long will curtailment pressures remain low, and what about land use issues as development moves into more populated regions?
Those are the questions that the Renewable Energy Pathways to Support Carbon Neutrality in China research project, led by Professors Davidson, Zhang, and Lu, aims to answer. The project is funded through the IGCC, with support from the California-China Climate Institute and Tsinghua University’s Institute for Climate Change and Sustainable Development.
As part of their work, the team is building an optimization model that incorporates granular data on wind and solar resources and key operational constraints in the electrical grid. They will forecast China’s electricity demand over the next four decades and use the model’s output to quantify energy capacities required between now and 2060, create detailed visualizations of the optimal locations for wind and solar sites, and identify the improvements to existing grid capacity that will be necessary.
The team believes the model can help policymakers anticipate when they will deplete the supply of resource-rich sites far from demand centers—and plan accordingly to avoid conflicts over land use in the more densely populated areas that will eventually need to host wind and solar infrastructure. Similarly, they believe the model can reveal at what point the further expansion of wind and solar sites will hinge on the deployment of complementary technologies, such as longer-lasting batteries. That information can help to spur timely investments in the technological advances that will be key to reaching carbon neutrality over time.
“Eliminating carbon emissions is an immensely difficult, unprecedented task. It’s going to require an enormous amount of new infrastructure and a lot of technologies that we don’t currently have,” stresses Professor Davidson. “Eventually, China is going to have to make some very difficult choices about land use, resource investments, and socioeconomic tradeoffs. This model, and others like it, can help policymakers guide that path more smoothly to avoid or limit conflict.”
The team is currently working to refine the various data points and scenarios that the model will incorporate. They anticipate that they will begin to run the model this summer, with preliminary results ready in the fall.
A Model Tailored to China, But Applicable Elsewhere
While the model is specifically tailored to China, the variables it considers are not unique to the country. Optimizing wind and solar site selection, understanding grid capacity, and anticipating challenges related to land use and technological limitations are issues that most countries will confront in the coming years. To that end, Professor Davidson sees the team’s work as highly applicable to other contexts.
“We’re already seeing many of the same issues China is grappling with, and will likely grapple with in the future, arise in places like India and the United States. The approach we’re using is especially relevant to countries that have a diversity of options for where to place wind and solar sites. With localized data, the same type of analysis could help other countries better plan for a carbon-neutral future.”
This feature story was prepared by Michael Karesky for the UC Institute on Global Conflict and Cooperation.
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