Government officials in the US have received a letter from over 100 environmentalists who pleaded to have more or unlimited investment in renewable energy. The environmentalist also requested that near-future solar panels must be put on roughly 8,000 miles of open-air canals and aqueducts owned/managed by federal government.
According to the environmentalists, such a project has the potential to generate over 25 gigawatts of renewable energy. It’s going to be enough to power nearly 20 million homes, and the solar-over-canals investment could reduce water evaporation by tens of billions of gallons.
In the letter, the environmentalists emphasized the benefit of this type of renewable energy plan: it could be carried out without destroying wildlife habitat, since the panels would be installed over existing structures.
The group, which consists of Greenpeace and the Endangered Species Coalition, believed that mounting solar panels on the canals wouldn’t produce just electricity. It would also lessen water loss caused by evaporation that brings droughts which have got worse due to climate change.
Moreover, the Center for Biological Diversity, a nonprofit conservation organization that co-signed the letter, said that the Interior Department should use renewable energy in areas that have already been developed instead of sacrificing more public lands. Thus, water canals are the wiser choice to build new solar farms.
“We don’t have to pave over thousands of acres of desert public lands and destroy wildlife habitat for renewable energy. This initiative can help reduce water loss, create jobs in frontline communities and preserve public lands,” said Brett Hartl, government affairs director of the nonprofit.
Benefiting many sides
The groups argued that by investing in such projects, governments can help bring the US into conformity with the Energy Act of 2020, which vowed to try to seek out leases for at least 25 gigawatts of electricity from wind, solar, and geothermal projects on federal land by 2025.
“The Bureau of Reclamation has full authority to carry out this plan. Congress has delegated authority to the Department of the Interior to grant leases to authorize uses of Bureau of Reclamation lands,” the environmentalists wrote.
Per the letter, many of the Bureau of Reclamation’s canals sit close to areas of poor air quality as well as a high concentration of communities who live in poverty.
“In addition to addressing air pollution, focusing the deployment of renewable energy on the bureau’s canal system could also provide additional benefits by providing clean energy that displaces existing dirty energy in those communities, while also providing increased job opportunities,” the letter stated.
In addition, supporters and advocates of desert land stated that the proposed projects would also aid in the preservation of desert ecosystems where officials may otherwise build renewable energy projects.
Cody Hanford, joint executive director at the Mojave Desert Land Trust, a California-based conservation group that signed the letter, emphasized this in a statement.
“We work with federal agencies every day to ensure that conservation is a part of our energy transition,” he said. “Prioritizing solar development on canals and in urban areas can help reduce pressure on our vulnerable desert wildlands,” Hanford stated.
Current, similar projects in the US
Installing solar panels over canals is not something new, but it’s not widely utilized yet.
For example, California has already started a pilot project called Project Nexus. It aims to build solar farms over some of its canals in the Turlock Irrigation District. The project is a collaboration between the state, a private company called Solar AquaGrid that will serve as project developer, and researchers at the University of California Merced.
Back in 2021, researchers found that covering California’s 3,945 miles of canals with solar panels could produce an enormous amount of clean energy every year. It would also slow the evaporation of 63 billion gallons of water—for an area prone to drought, that’s certainly an exciting prospect.
To address the issue of costly installation, the researchers said that while the steel trusses and cables used to suspend solar panels over waterways are more expensive than traditional ground or roof mounting solutions, they are much cheaper than the cost of land acquisition.
“Until this UC Merced paper came out, we never really saw what those co-benefits would be. If somebody was going to pilot this concept, we wanted to make sure it was us,” said Josh Weimer, external affairs manager for the district.
Learning from solar-farms-over-canals abroad
Other countries like India have begun to install similar systems as well. In fact, India pioneered it on one of the largest irrigation projects in the world. And, we can always learn a lesson or two from everyone who pioneers things.
There used to be such a project over The Sardar Sarovar dam and canal which bring water to hundreds of thousands of villages in the dry, arid regions of western India’s Gujarat state.
The chief minister of Gujarat state Narendra Modi—now the country’s prime minister, inaugurated it in 2012 with much fanfare. The engineering firm, Sun Edison, promised 19,000 km (11,800 miles) of solar canals.
Unfortunately, there were only a handful of smaller projects that have gone up and the firm had filed for bankruptcy.
According to Jaydip Parmar an engineer in Gujarat who oversees several small solar canal projects, the projects must stop because the capital costs were really high and there was an ongoing issue with maintenance.
Another reason why the technology hasn’t been widespread in India is due to clunky design. The panels in Gujarat’s pilot project sit directly over the canal, giving very minimum access for maintenance and emergency crews.
In the end, with the area’s ample arid land, ground-based solar made more sense, economically speaking.
However, despite its “failure,” the project was expected to generate 1 megawatt of electricity while preventing the evaporation of 2.4 million gallons of water annually. And, the price per megawatt was found to be substantially lower than that of traditional solar farms.
Based on these issues and experience, current projects have taken notes and tried to come up with better solutions.
What about placing solar panels on oceans?
Since canals seem to provide benefits to the environment and the people, what about placing panels on oceans? Won’t it be similar, since the sun always shines directly on oceans?
Well, research suggests that vast arrays of solar panels on calm equatorial oceans could offer nearly limitless solar energy to densely populated areas.
Andrew Blakers and David Firnando Silalahi at The Australian National University, Canberra, found that Indonesia’s offshore solar potential alone could match the world’s current annual electricity production.
Equator regions like Indonesia and West Africa, per the research, has the upper hand when compared to most oceans because they remain peaceful, and they require relatively affordable engineering for offshore solar protection.
Blakers and Silalahi added that crowded countries like Indonesia would benefit from solar energy placed on equatorial seas due to limited space and wind resources.
The researchers wrote, “Our recently released paper surveys the global oceans to find regions that didn’t experience large waves or strong winds over the past 40 years. Floating solar panels in such regions do not require strong and expensive engineering defenses.
“Regions that don’t experience waves larger than 6 meters nor winds stronger than 15m per second could generate up to one million TWh per year. That’s about five times more annual energy than is needed for a fully decarbonized global economy supporting 10 billion affluent people.”
Now, Indonesia could opt to have vast numbers of floating solar panels on its calm inland seas—the country has about 140,000 square km of seascape that has not experienced waves larger than 4m nor winds stronger than 10m per second.
The researchers believe that Indonesia’s maritime area of 6.4 million square km is 200 times larger than required if Indonesia’s entire future energy needs were met from offshore floating solar panels.