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Can Sea Water Desalination Save The World? | News Cover

Can Sea Water Desalination Save The World? | News Cover. These aren't just issues in developing countries. Something you hear about elsewhere. These are things that are happening in our communities all the time. Worried and angry about lead contamination. The military in remote parts of Puerto Rico. And that's the result of many things. But one of them is that ninety-six point five percent of that water is found in our oceans. It's saturated with salt and undrinkable. And most of the earth's fresh water is locked away in glaciers or deep underground. Less than 1 percent of it is available to us. News cover, the news cover, World, world news, desalination plant, seawater desalination, seawater to drinking water, water desalination plant, thermal desalination

Sunday, October 27, 2019

/ by Avishek Bera
News cover, the news cover, World, world news, desalination plant, seawater desalination, seawater to drinking water, water desalination plant, thermal desalination

News Cover: Seventy-one percent of our planet's surface is covered in water. Three hundred and thirty-two point five million cubic miles of it. Three hundred and sixty-six billion billion gallons. That's over forty-eight billion gallons of water for every person on Earth. But today, one out of three people don't have access to safe drinking water. Some projections will show by 2050, more than half our population will be living in water-stressed areas. That's over four billion people. 

    These aren't just issues in developing countries. Something you hear about elsewhere. These are things that are happening in our communities all the time. Worried and angry about lead contamination. The military in remote parts of Puerto Rico. And that's the result of many things. But one of them is that ninety-six point five percent of that water is found in our oceans. It's saturated with salt and undrinkable. And most of the earth's fresh water is locked away in glaciers or deep underground. Less than 1 percent of it is available to us. 

    When you dig a little bit and look under the surface, even here in the United States, we have large numbers of people that don't have access to safe, clean drinking water. 

   What is Desalination: Desalination broadly is the process of removing salts from water. It's been practiced for years. In fact, it's a natural process. It occurs when the sun heats the ocean and freshwater evaporates off and it falls again as rainfall. 

    If you mix salt into water, it dissolves. And if you could watch microscopically while you did that, you'd see that the water is actually breaking apart the salt into charged particles that chemically interact with the water. So saltwater is a chemically new solution. It's not just water with some salt grains floating around in it. And that's why desalination is a fundamentally tricky process.

     Type of Desalination: The two main types of desalination are thermal desalination and reverse osmosis. 

    Thermal desalination is the oldest form of desalination. It's essentially boiling water and then capturing the steam and turning that into freshwater. But in the 60s, we were able to develop reverse osmosis processes at UCLA and these have now started to dominate the market. So one of the chief differences between the two is reverse osmosis doesn't use heat, doesn't boil anything. You're really just pressurizing the water to a tremendous amount and you're forcing it through a membrane where it doesn't want to go. It wants to stay with the salt. But with this high pressure, it is forced to separate from the salt. Broadly speaking, what you want to look at for desalination is where's my freshwater coming from and do I have enough of it? And if I don't have enough of it, do I need to augment supply? Desalination then starts to become a very attractive or interesting option. 

    This is why the vast majority of desalination efforts right now are happening in places like the Middle East and North Africa. Rich with fossil fuels, but also experiencing extreme water scarcity. 

    Just two countries, Saudi Arabia and UAE, they produce one-fourth of the desalination water that is produced currently on this planet. 

    Concerns about desalination fall broadly into three categories: the amount of energy required, how much it costs, and its environmental impacts. There are some that really see it as a key solution. There are others that push back and argue that it's very energy-intensive. It's very expensive. It has impacts on the marine environment and that we should pursue alternatives first. 

     It requires a tremendous amount of energy to basically break up that bond between the water and salt. Ocean water desal can be twenty-five times as energy-intensive as other freshwater approaches. 

    Historically, the impediment for seawater desalination being more abundant or popular in North America has cost. It has been cost-prohibitive historically. The Cloud Lewis Carlsbad desalination plant outside of San Diego is the largest of its kind in the Western Hemisphere and has been operating since 2015, producing 50 million gallons of clean water a day. It's in San Diego County because of its dry, arid climate. The county has historically imported nearly all of its water from the Colorado River and Northern California. 

     In San Diego, in Carlsbad example, they are spending twice as much for seawater desalination as they do on imported water. Now, they were looking at it and saying, well, at some point in the future, the costs will be comparable. And I think some folks point it to the fact that, well, when that's the case, then that's probably when you should build it. 

    Today, desalinated water in Carlsbad costs approximately twice as much as imported water. You're comparing apples and oranges because that imported water is coming from systems that were built half a century ago where all the capital investment has been paid off. Standing down for 5 or 10 years, hoping there's some major breakthrough in the technology is not going to materially reduce the cost of building infrastructure. That's not unique to desal and water. It's true of all public infrastructure. We have a huge deficit. We need to start building not just water, but transportation and housing. Now, not 5 or 10 years from now. 

   The Carlsbad plant is operated as a public/private partnership with the Carlsbad Seawater desalination plant. In the proposed Huntington beach seawater desalination plant, we're proposing a public/private partnership where the plant is 100 percent privately financed and then we enter into a longterm, fixed-price water purchase agreement with the public water agency. Essentially, we're recovering our investment over time through the sale of water. 

   There's an infrastructure deficit in the United States. There's certainly an infrastructure deficit in California. And you can't expect local, state and federal government to pay for all of it. The private sector is going to have to invest private dollars. And I think there's a huge opportunity in water in a way that both protects the ratepayers and also allows for the investment of private capital.

     Beyond the environmental costs of producing the energy needed to power these plants. Another concern arises because they're not just outputting clean desalinated water. They're also producing huge amounts of hyper salty water, called brine, as a byproduct. 

     Seawater desalination plants that use reverse osmosis typically operate at a 50 percent efficiency in that if you take in two gallons of seawater, you're going to produce one gallon of freshwater and one gallon of hypersaline brine. 

       It's a fixed volume of salt that I'm trying to remove. So whether I put it in half a gallon of water or a tenth of a gallon of water, it's still going to be there and it's going gonna be much more concentrated. 

        As desalination efforts grow, it's not clear what should be done with these huge amounts of brine. Globally right now, we're producing over 37 billion gallons a day. Most brine is in one way or another emptied back into the ocean. But because it has a much higher salt concentration than regular seawater, it has the potential to, among other things, sinks to the seafloor and wreaks havoc on the plants and animals found there. In addition, because these facilities are taking in millions of gallons of seawater a day, the intake itself could destroy local marine life. 

        But Poseidon Water, which operates the Carlsbad plant, says the regulations in California provide sufficient environmental protection. Numerous studies have been done in California and around the world that show that the level of salinity increase will not harm marine life. And you're also providing drinking water to people in need. But a recent study published in 2018 showed that we're producing even more brine than we thought. 

For every liter of desalinated water, we produce 1.5 liters of brine. In other words, overall, we are producing more brine than we produce desalinated water. 

     And while some places like California have robust regulations regarding brine in place, it's not clear that as a whole the industry is taking its disposal seriously enough. 

Currently, we are disposing of brine in a way that we use to dispose of industrial wastewater about 40-50 years ago. 

     So if desalination uses a huge amount of energy, is very expensive compared to other options, and in the end, we're producing more potentially harmful brine than clean water, why do we continue to pursue it? Desalination has its drawbacks, but one of the benefits is that it's a fairly stable and known process particular for dealing with ocean water. You can be confident that it will supply you water when you need it. 

      Reliability is key. Water scarcity is a complex, difficult problem. Climate change is affecting everything and introducing growing uncertainty. Weather is variable, but if you have a desalination plant, energy, and seawater, you can reliably get clean water. But desalination undeniably uses a large amount of energy. And for some, it's just fundamentally difficult to advocate for a technology that would be adding to our ever-growing energy needs. 

        I think when we start to look into these water-scarce worlds, we start to think about good energy provides us services. It heats our homes, it lights our offices and buildings. And if we think of energy as a service that could give us water for some context, you know, the average person. uses about a hundred gallons of water per day. If I were to produce that a hundred gallons per day with ocean water desal, that would be the same electricity consumption that my home would require over an hour. So to kind of put things in context, I think we start to think about our energy resources and where do I invest it? How important is water? 

        It is the most basic element of life. And people go out and they buy a venti Starbucks every day and spend more on that than they do for a month's supply of desalinated water. And they don't realize it. 

      It's clear that desalination alone is not going to fix the world's water problems. Up in some places where you're just water rich, desalination probably won't make the most sense. Poseidon Water as a company does not believe that seawater desalination is a panacea. 

      We can't just build one or two or 10 and really solve our water challenges. Desalination is not the solution to water scarcity. It's one of the options to narrow the gap between water supply and demand. But for some communities around the world, it's already making an enormous local impact. It's currently a pretty small fraction of the water supply globally and probably will remain so. 

     There are, though, communities for which it is a fairly significant contribution. It can be quite important at the local level. Desalination is one tool of many. And for it to have maximum impact, it must be implemented alongside other techniques. Israel maybe provides a good example where they have invested quite a bit in seawater desalination, but they also made investments in efficiency such that their water use on a per person basis is far lower than we see here in California or in many, many parts of the United States. So they did those things first so that they aren't wasting that very expensive water. That then delayed their need to build a plant. And when they built it, they could build it a bit smaller than they would have. So there's a cost, a real cost saving there to the community. 

        I would almost look at it as a safe bet, you know, to hedge your risks. A desalination plant is your low-risk option in your portfolio. Kind of expensive, maybe, but it's going to deliver. 

       I think we do the cheaper, less environmentally damaging things first. That seawater desalination is an option. In some communities, they don't have other options. Others, though, do have other options. They can use water more efficiently, which can save water, save energy, can have a less environmental impact. 

           And while most attention is given to seawater desalination, a similar process can be used for treating many other sources of water like wastewater. The volume of waste water, if it's all collected and recycled, that is almost equivalent to five times the volume of water that passes through Niagara Falls each year. And if we look at the desalinated water, the desalinated water, which we produce globally, on an annual basis is almost equal to half of the volume of the water that passes through Niagara Falls. 

      We don't want to lose sight of other sorts of desal, brackish water, which is, you can think of brackish water is it's not as salty as ocean water, but it's saltier than freshwater. It's that whole space between and there the energy requirements are substantially less simply because there's less salt. So less salt, less stuff to remove, less energy. 

      A desalination is an important tool in the fight against water scarcity. Its reliability is becoming ever more important, but it's not a cure-all and other techniques should always be implemented alongside it. Desalination is already vital for many water-scarce communities around the world. And as climate change continues to transform our planet, the balance between concerns about energy use and the ability to reliably get clean water is going to evolve. How exactly desalination will fit into the future of clean water is yet to be seen...

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