Seawater to freshwater: The new era of clean water tech

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  Quantumrun Foresight
• November 26, 2024

Insight summary

Desalination is becoming an essential solution for regions facing water shortages, transforming seawater into drinkable water. While this process can be energy-intensive and potentially harmful to marine ecosystems, new research is exploring ways to reduce these negative impacts by using renewable energy and improving waste management. As desalination grows, it could reshape industries, create new jobs, and prompt governments to implement policies ensuring equitable access to fresh water.

Seawater to freshwater context

Desalination, the process of removing salt and other minerals from seawater to produce fresh water, is a crucial solution to the growing global water crisis. With freshwater sources rapidly depleting and an estimated 1.1 billion people lacking access to safe drinking water, regions affected by water scarcity are turning to seawater desalination to meet their needs. Historically, desalination dates back to the 1600s when the first patent for such a system was issued in England. Today, countries like Saudi Arabia and the US lead in desalination efforts. However, despite the expansion of desalination plants—especially in desert regions like the Middle East—the process accounts for only a fraction of the water supply in many areas. For example, in 2024, desalination provided just 10 percent of the drinking water in San Diego, home to the largest desalination plant in the US.

Technologically, reverse osmosis is the most common method for desalinating water, which involves applying pressure to force seawater through a semi-permeable membrane and filtering out salt and impurities. However, the process is energy-intensive, with energy costs accounting for up to 40 percent of a plant's operational expenses. This reliance on energy, often sourced from fossil fuels, contributes to greenhouse gas emissions, creating a dilemma for environmentally conscious regions. Additionally, desalination generates a concentrated saline byproduct, or brine, which is typically disposed of in the ocean. This practice poses a significant risk to marine ecosystems by increasing ocean acidification. 

Despite these challenges, research institutions such as the National Renewable Energy Laboratory are exploring ways to power desalination plants using renewable energy, such as wave power, to reduce the carbon footprint of these operations. Recent advancements in desalination technology have also opened up new possibilities for smaller, more sustainable solutions. For example, researchers from the Massachusetts Institute of Technology and Shanghai Jiao Tong University developed a rooftop desalination system in 2024 that produces a gallon of potable water per hour using solar energy and passive filtration. 

Disruptive impact

As more people face water shortages, small-scale desalination systems could allow coastal households to generate freshwater. This shift may lower dependence on municipal water supplies, potentially reducing water bills and providing a reliable source of clean water even during droughts. However, access to these systems might remain limited to wealthier individuals due to high initial costs. Additionally, widespread adoption could lead to environmental issues, as improper disposal of concentrated brine could damage local ecosystems and affect people who depend on marine resources for their livelihoods.

For companies involved in manufacturing desalination systems, renewable energy solutions, and water filtration materials, they could see increased demand. Industries relying heavily on water, such as agriculture and food processing, may need to integrate desalination into their operations to secure water supplies. However, businesses face high upfront costs and the challenge of managing the environmental impact of brine disposal. To stay competitive, companies may need to adopt more sustainable practices and explore alternative uses for brine, such as extracting valuable minerals like magnesium or lithium.

Meanwhile, governments may face pressure to adapt their policies and investments to support the growth of desalination. As climate change intensifies water scarcity, public infrastructure projects may need to prioritize desalination plants, especially in drought-prone regions. International cooperation may become crucial, particularly in areas like the Middle East, where cross-border water conflicts could arise. Additionally, governments may need to provide subsidies or incentives to make desalination technologies affordable for lower-income populations, ensuring equitable access to fresh water.

Implications of seawater to freshwater

Wider implications of seawater to freshwater may include: 

• Coastal communities experiencing population growth as access to fresh water through desalination becomes more reliable, making these areas more attractive to residents and businesses.
• Rising demand for specialized desalination technologies prompting the creation of new industries focused on water purification materials and equipment manufacturing.
• Local fishery industries being impacted as brine discharge from desalination plants leads to shifts in marine ecosystems, requiring new environmental regulations.
• Water-intensive industries, such as agriculture, adopting desalination technologies to secure water supplies, potentially increasing food prices due to higher operational costs.
• Job markets growing in desalination technology research, maintenance, and installation, offering new career opportunities in water management and sustainability sectors.
• Environmental advocates pushing for stricter regulations on brine disposal, leading to technological advancements in waste management and minimizing ecological harm.
• Urban planners incorporating desalination facilities into city infrastructure projects, potentially changing the way large urban areas manage water resources and plan for future population growth.

Questions to consider

• How could access to small-scale desalination systems change how you manage water usage at home?
• What impact might desalination have on the cost and availability of food in your community?