Study Proposes Covering Highways With 52 Billion Solar Panels – CleanTechnica

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Researchers from the Chinese Academy of Sciences, Tsinghua University, Chinese Academy of Geosciences, and Columbia University have proposed a historic initiative they say would generate 60 percent of the electricity the world uses each year and slash carbon emissions by 28 percent. Is that crazy talk? Maybe, maybe not. Here’s the plain language summary of their study, which was published in the journal Earth’s Future on July 15, 2024.

“Global efforts are underway to diversify environmentally sustainable strategies for photovoltaic (PV) installations to enhance the accessibility of green electricity. Here, we propose an innovative strategy to roof highways with PV panels and evaluate their electricity generation potential and social-economic co-benefits. Our analysis reveals that globally deploying highway PV systems across existing highway networks has the potential to generate 17,578 TWh of electricity annually, offsetting nearly 28% of concurrent global carbon emissions. Additionally, the highway PV could potentially prevent 150,000 traffic deaths annually and bring profits amounting to $14.42 trillion over a 25 year lifetime. We emphasize that the highway PV may serve as a crucial nexus for promoting human, environmental, and economic sustainability.” The researchers estimate the nations of the world would need to install more than 52 billion solar panels over their highways to maximize the potential of their proposal.

Solar Panels Over Highways

Does that sound like something you would like to know more about? Good. Here are some details, courtesy of EcoNews. The researchers advocate for the deployment of solar technology across the global highway network — a total of 3.2 million kilometers (2 million miles) of roads as of today. Ling Yao, the study’s lead author, said the research really surprised him. “I didn’t realize that highways alone could support the deployment of such large photovoltaic installations, generating more than half of the world’s electricity demand and greatly easing the pressure to reduce global carbon emissions.” Pilot projects that have installed solar panels over highways have already been successful in the United States, China, Germany, Austria, and Switzerland.

However, while the data shows promising results, it is important to consider limitations to the quantitative research. The researchers acknowledge in their paper how climate conditions vary around the world. This variation in climate change would impact the efficiency of the solar roofing system from “spatially differentiated fluctuations.” They also acknowledge that in order to offset carbon emissions, the electricity generated will need to replace thermal generation powered by fossil fuels — coal and methane, mostly. A lot will depend on the structure of regional power supplies, grid efficiency, and transmission losses. In addition, the carbon footprint of the construction of the roofing system could negate the carbon benefits for 1.1 years.

Further challenges associated with the construction of the highway system include the estimated cost of construction and the need for regular and vigorous maintenance of the system. Nevertheless, the proposed initiative offers promising data towards increasing the use of solar energy as a power source. While the proposed project is still considered exploratory research and, if implemented, will incur high logistical and economic costs, the prospects for this creative use of solar panels looks promising.

Twin Benefits Of Solar Above Highways

These projects imply that the benefits of the highway PV mainly embody two aspects, the researchers maintain. First, highway PV can reduce CO2-equivalent emissions by generating green electricity that can be delivered to the grid, thereby replacing electricity that would otherwise be generated by fossil fuel sources. If the space above highways is entirely devoted to solar panel installations, considerable amounts of green electricity can be generated to offset carbon emissions, contributing to a net zero emissions future. Meanwhile, the use of already developed highway surfaces is beneficial because this would not add more impervious surfaces that may impact groundwater resources.

Second, the unique advantage of solar panels mounted over highways rather than ground-mounted PV systems lies in the enormous reduction of road traffic losses, the researcher forecast. As the eighth leading cause of death worldwide, traffic accidents claim approximately 1.35 million lives and cause 50 million injuries each year. The socio-economic burdens associated with these accidents are estimated to be about 2.7 percent of gross domestic product in high-income countries and 2.2 percent of GDP in low- and middle-income countries. Solar panels over highways can protect cars from adverse weather conditions such as rain, snow, and ice, thereby reducing the incidence of traffic accidents and the ensuing deaths and socio-economic burdens associated with them.

The benefits of installing solar panels over highways have not been widely recognized, which means those benefits have not yet been realized to the fullest extent possible. The research evaluated the economic feasibility of their proposal by modeling the electricity generation per length of the highway and calculating the levelized cost of electricity. They then quantified the CO2e emission reductions based on country-level grid emission factors and estimated the reduced traffic losses via a probabilistic decomposition model that simulates the impact of both road weather conditions and driving speed on the traffic accident risks. Their analysis shows that huge returns can be attained if the proposed highway PV systems are implemented globally.

A Solution To An Urgent Problem?

The research published in Earth’s Future showcases promising data-driven results. If implemented successfully, the project could generate up to four times the amount of energy produced in the United States annually. A green future is on the horizon, and is gaining speed every day, EcoNews says. That is a very optimistic reading of the current political situation in many places around the world, where demonizing “the other” is the latest blood sport. However, the need is urgent and anything that might get us out of the planet-destroying mess we are in today should at least be given consideration.

While the research may be hypothetical and data driven, the thinking-outside-the-box nature of the project is what the world is desperately needing more of, EcoNews says. To promote a radical shift from fossil fueled energy to green energy, radical ideas need to be considered. As the world moves into the 5th industrial revolution, never before has technological innovation been as robust as it is today. Green energy innovation is at its peak and a global solar panel network is not a question of “maybe,” but one of “when.”

Innovative and radical solutions such as solar panels over global highways are ideas that are becoming increasingly more relevant as the world goes green. We already put solar panels over canals. The idea to put them over roads may seem weird, but doing nothing and letting average global temperatures soar by 3°C (5.4°F) is even weirder — and a death sentence for hundreds of millions of people. This idea may strike many readers as too far out, but is it any more far out than geoengineering that no one knows will work and will cost trillions of dollars to find out? We can’t all fly away to Elon Musk’s utopia on Mars. This idea is not so strange when you stop to consider the alternatives.