Solar device converts salt water into drinking water at record speed – earth.com

Report on a Novel Solar-Powered Desalination Device

Introduction

A new solar-powered desalination device developed by the Ulsan National Institute of Science and Technology (UNIST) presents a significant advancement in sustainable water purification. The technology operates without external power, converting seawater into potable water, thereby directly addressing critical global challenges outlined in the United Nations Sustainable Development Goals (SDGs), particularly SDG 6 (Clean Water and Sanitation) and SDG 7 (Affordable and Clean Energy).

Technological Mechanism and Performance

Core Innovation

The device’s efficacy is rooted in its innovative design and material science, which contributes to SDG 9 (Industry, Innovation, and Infrastructure).

• Photothermal Material: It utilizes La0.7Sr0.3MnO3, a perovskite oxide, which efficiently absorbs a broad spectrum of sunlight and converts it directly into heat at the water’s surface. This localized heating minimizes energy loss.
• Salt Management System: A unique membrane design uses capillary action for water flow. This unidirectional movement pushes salt crystals to the edge of the device, preventing fouling of the photothermal surface and ensuring continuous operation.
• Zero Liquid Discharge (ZLD): By isolating and collecting salt, the system avoids the discharge of high-salinity brine back into the environment. This aligns with SDG 12 (Responsible Consumption and Production) and SDG 14 (Life Below Water) by preventing marine pollution.

Performance Metrics

In controlled and real-world tests, the prototype demonstrated robust and efficient performance.

1. Water Production: The device produces approximately 0.084 gallons of freshwater per square foot per hour.
2. Durability: It maintained steady performance for two weeks while processing water with a 20 percent salt concentration.
3. Water Quality: The condensed water produced meets safety standards, falling well below the guidelines for drinking water established by the World Health Organization (WHO).

Alignment with Sustainable Development Goals (SDGs)

SDG 6: Clean Water and Sanitation

This technology is a direct response to SDG 6, which aims to ensure the availability and sustainable management of water and sanitation for all.

• It provides a decentralized solution for producing safe drinking water, crucial for the one in four people globally who lack access.
• Its off-grid nature makes it ideal for remote, coastal, or resource-limited communities.

SDG 7: Affordable and Clean Energy

By operating solely on solar power, the device strongly supports the transition to sustainable energy systems.

• It eliminates the need for an electrical grid connection, reducing infrastructure costs and dependencies.
• It offers a carbon-free alternative to energy-intensive conventional desalination plants, contributing to climate action (SDG 13).

Scalability and Future Implications

Modular and Accessible Design

The system’s design facilitates scaling and practical deployment, which is essential for achieving widespread impact and supporting SDG 11 (Sustainable Cities and Communities).

• Modularity: The device is constructed from simple modules that can be assembled into larger arrays. This allows communities to scale their water production capacity based on local needs and resources.
• Ease of Maintenance: The modular approach simplifies repairs, as individual units can be replaced without shutting down the entire system.
• Manufacturing: The use of screen-printing techniques for material application suggests a pathway to scalable manufacturing without reliance on complex or rare components.

Conclusion

The UNIST solar desalination device represents a promising technological solution that integrates multiple Sustainable Development Goals. By providing clean water through clean energy, promoting responsible production, and offering a scalable infrastructure model, it has the potential to significantly improve water security and resilience for communities worldwide.

Analysis of Sustainable Development Goals (SDGs) in the Article

1. Which SDGs are addressed or connected to the issues highlighted in the article?

1. SDG 6: Clean Water and Sanitation
   • The entire article focuses on a new technology that “turns seawater into safe drinking water.” This directly addresses the global challenge of water scarcity and the need for clean water, highlighted by the statistic that “one in four people still lack safely managed drinking water.”
2. SDG 7: Affordable and Clean Energy
   • The device operates “without any external power,” using only sunlight. This aligns with the goal of increasing the use of renewable energy sources, particularly for “communities with strong sunlight but limited energy access.”
3. SDG 9: Industry, Innovation, and Infrastructure
   • The article describes a significant technological innovation from the Ulsan National Institute of Science and Technology (UNIST). It discusses the research, the prototype’s performance, and potential “manufacturing routes,” all of which are central to fostering innovation and developing sustainable infrastructure.
4. SDG 12: Responsible Consumption and Production
   • A key feature of the device is its ability to enable “Zero Liquid Discharge (ZLD) through effective salt collection.” Instead of returning concentrated brine to the ocean, which is a harmful byproduct of traditional desalination, this technology collects the salt. This represents a more sustainable production pattern by minimizing waste and pollution.

2. What specific targets under those SDGs can be identified based on the article’s content?

1. Under SDG 6 (Clean Water and Sanitation):
   • Target 6.1: “By 2030, achieve universal and equitable access to safe and affordable drinking water for all.” The article directly supports this by presenting an “affordable” device that produces “safe drinking water” and can be deployed where “pipes, pumps, and grids fall short.”
   • Target 6.4: “By 2030, substantially increase water-use efficiency across all sectors and ensure sustainable withdrawals and supply of freshwater to address water scarcity.” The technology creates a new supply of freshwater from an abundant source (seawater), directly addressing water scarcity.
   • Target 6.b: “Support and strengthen the participation of local communities in improving water and sanitation management.” The article notes the system can be run “without skilled labor” and its “modular nature” allows communities to “match output to local water needs,” empowering local management.
2. Under SDG 7 (Affordable and Clean Energy):
   • Target 7.2: “By 2030, increase substantially the share of renewable energy in the global energy mix.” The device’s reliance solely on solar power is a direct contribution to this target.
3. Under SDG 9 (Industry, Innovation, and Infrastructure):
   • Target 9.5: “Enhance scientific research, upgrade the technological capabilities of industrial sectors…” The article is a report on a scientific breakthrough (“The study is published in Advanced Energy Materials”) that represents an upgraded technological capability in desalination.
   • Target 9.4: “By 2030, upgrade infrastructure and retrofit industries to make them sustainable…and greater adoption of clean and environmentally sound technologies…” The Zero Liquid Discharge (ZLD) feature is an example of an environmentally sound technology that makes the process of desalination more sustainable.
4. Under SDG 12 (Responsible Consumption and Production):
   • Target 12.5: “By 2030, substantially reduce waste generation through prevention, reduction, recycling and reuse.” The device’s ability to collect salt instead of discharging it as brine is a direct form of waste prevention and reduction.

3. Are there any indicators mentioned or implied in the article that can be used to measure progress towards the identified targets?

1. Indicator for Water Quality (Target 6.1): The article explicitly states that the produced water quality was measured and “was well below the World Health Organization (WHO) guidelines for safe drinking water.” This provides a clear, measurable indicator of success.
2. Indicator for Water Production Efficiency (Target 6.4): The article provides specific quantitative data on the device’s output, such as producing “roughly 0.084 gallons of freshwater per square foot each hour” and capturing “roughly 2.46 pounds per square foot as liquid water” in outdoor tests. These metrics can be used to measure its efficiency in addressing water scarcity.
3. Indicator for Renewable Energy Use (Target 7.2): The primary indicator is the energy source itself. The fact that the device runs “without external power” and relies on sunlight is a qualitative but absolute measure of its contribution to renewable energy use in the water sector.
4. Indicator for Waste Reduction (Target 12.5): The achievement of “Zero Liquid Discharge (ZLD)” is a direct indicator. This can be measured by the amount of salt collected versus the amount of brine discharged, which in this case is zero.
5. Indicator for Scientific Advancement (Target 9.5): The publication of the research in a peer-reviewed journal, “Advanced Energy Materials,” serves as an indicator of a contribution to scientific knowledge and technological advancement.

4. Table of SDGs, Targets, and Indicators

Source: earth.com