Fiber-Optic Solar Toilet Turns Sewage Into a Plant-Friendly Resource
What if a fiber-optic solar toilet could operate without water. Then you use the power of the sun and turn human waste into something useful?
That was the idea behind an innovative solar-powered toilet developed by engineers at the University of Colorado Boulder. Moreover, the technology tackled two enormous global challenges at once: sanitation and access to clean water.
The project gained attention around World Water Day in 2014. At the time, roughly one billion people lacked access to safe drinking water. Meanwhile, inadequate sanitation continued to contaminate water supplies and threaten public health around the world. (The Green Living Guy)
A Fiber-Optic Solar Toilet Powered by the Sun
Instead of relying on water to flush waste into a sewer system, the experimental toilet used concentrated solar energy.
The system featured eight parabolic mirrors. First, those mirrors concentrated sunlight onto an extremely small collection point. Then, fiber-optic cables transported that concentrated solar energy directly into a reaction chamber.
Consequently, the chamber could heat human waste to temperatures reaching about 600 degrees Fahrenheit. (The Green Living Guy)
That high temperature served an important purpose. Rather than simply moving sewage somewhere else, the system treated the waste directly.
Fiber-Optic solar toilets Make the Technology Different
Concentrated solar energy itself wasn’t new. However, the researchers approached it differently.
They used fiber-optic cables to move concentrated sunlight to the location where engineers actually needed the heat. Therefore, the solar collection equipment didn’t necessarily have to sit directly above the treatment chamber.
University of Colorado Boulder environmental engineering professor Karl Linden described that ability to flexibly transmit concentrated solar energy through fiber optics as one of the project’s most distinctive features. (The Green Living Guy)
In other words, engineers combined solar thermal technology with sanitation technology in a completely different way.
From Human Waste to Something Useful
Here’s where the concept gets even greener.
Human waste normally creates a sanitation problem. However, properly treated waste can contain potentially valuable nutrients and materials.
Therefore, the goal wasn’t simply to destroy sewage. Instead, technologies like this can help shift sanitation toward resource recovery.
That represents an important change in thinking. Waste doesn’t always have to remain waste.
Instead, we can design systems that recover resources while protecting water supplies.
Saving Water While Improving Sanitation
The water savings could also become significant.
Traditional flush toilets use clean water simply to transport waste. Yet many communities around the world already struggle to obtain enough safe water for drinking, cooking and basic hygiene.
A waterless sanitation system changes that equation.
Because the solar toilet doesn’t depend on a conventional water-based sewer connection, it could potentially serve areas where extensive sanitation infrastructure doesn’t exist. Moreover, solar energy provides a renewable heat source for treating the waste.
That’s especially important in regions with abundant sunshine but limited access to electricity, clean water or centralized sewage treatment.
Solar Power Meets the Circular Economy
This technology also demonstrates something much bigger.
Renewable energy isn’t only about replacing coal and natural gas on the electrical grid. Solar energy can also provide heat, clean water, transportation and, yes, even sanitation.
Meanwhile, circular-economy thinking asks us to reconsider what we call waste.
Put those ideas together and a toilet suddenly becomes much more than a toilet.
It becomes a small treatment system, conserves water and harnesses renewable energy. Furthermore, it can potentially recover useful resources from something society normally throws away.
Conclusion: Turning a Dirty Problem Into a Clean Solution
Sanitation may not be the most glamorous part of the green technology revolution. Nevertheless, it remains one of the most important.
Clean water saves lives. Proper sanitation protects communities. Meanwhile, renewable energy can help provide both without requiring the same massive infrastructure everywhere.
The University of Colorado Boulder solar toilet showed just how creative engineers can get when they rethink an everyday necessity. (The Green Living Guy)
After all, when sunlight, fiber optics and smart engineering can transform sewage from a pollution problem into a potential resource, that’s the kind of green innovation worth talking about.
Outside Sources
The World Health Organization’s sanitation research explains why access to safe sanitation remains a major global challenge. WHO also highlights opportunities to safely recover water, nutrients and energy from wastewater and human waste.
Meanwhile, the World Health Organization’s drinking water research shows how inadequate sanitation can contaminate drinking-water supplies and create serious public health risks.
WHO reports that 2.2 billion people lacked safely managed drinking-water services in 2022. It also explains how fecal contamination of water creates serious public-health risks.
Finally, the World Health Organization’s Water, Sanitation and Hygiene program provides additional information about the connection between clean water, sanitation, hygiene and healthier communities worldwide.
Top Image: CU Boulder postdoctoral researcher Tesfayohanes Yakob (left) and research engineer Dana Haushulz with a solar-thermal toilet. Photo courtesy University of Colorado.
Original post….March 19th, 2014 | by Michael Keller
