Innovations in Desalination

Innovations in Desalination

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Thank you so much for being here. I want to open our briefing today by acknowledging that we're calling in from different locations in what we now call the state of California, which is home to many indigenous communities that have stewarded this land since time immemorial. My name is Brie Lindsey. I'm the Director of Science Services and filling in for our Deputy Director who started this briefing.

And I'll introduce CCST, our Disaster Resilience Initiative. And then I will welcome our moderator for this briefing, Dr. Eric Hoek The California Council on Science and Technology is a nonpartisan and nonprofit organization that was established 35 years ago, at the request of the legislature. CCST has created was created to provide science and technology advice from a wealth of outstanding academic and research institutions in our state directly to policymakers. California is so lucky to have such an incredible network of expertise, and our job here is to help amplify and translate the expertise in this network into actionable advice for policymakers.

And we do this through a number of different mechanisms, including the briefings like the one you're attending today. We host workshops, we write peer reviewed reports, and we run the CCST Science Fellows program, where we place PhD scientists and engineers in the executive branch in the legislature for a year of government service and leadership training as part of our mission, CCST is advancing work related to our Disaster Resilience Initiative to help the state better prepare for and respond to the ongoing complex and intersecting disasters that affect public health, our economy and our environment. These include climate change, extreme heat, power outages and the COVID 19 pandemic, which are all radically disrupting the ways in which Californians live and work. While these disruptive while these disruptions are actually quite destructive and painful, they can also provide us opportunities to redesign our systems to be more resilient and sustainable. And through our Disaster Resilience Initiative, we are seeking to deliver science and technology advice to reduce harm and improve the lives of all Californians. Today, we're focusing on how innovations in desalinate and technology could help improve California's resilience to drought.

And so I'd like now to introduce our excellent moderator, Dr. Eric Hoek. Eric is a professor at UCLA and the faculty director of UCLA's Sustainable LA Grand Challenge, a campus wide initiative in partnership with the city of L.A. to keep help L.A. become the world's most sustainable megacity by 2050.

Eric is an engineer by training. His research focuses on nanomaterials, membrane technology and electrochemistry with a focus on water, energy and environmental applications. Eric also brings an industry perspective. Having co-founded several technology companies focused on producing innovative membrane technologies for water treatment, desalination and recycling.

We're grateful to have you with us here today, Eric, and thank you so much for bearing with our technical difficulties. Thank you. Hey Brie, thank you. Good to be working with you again. As we all know, California is currently facing what will likely be a fourth year of historic drought conditions as climate change threatens California's and much of the world's fresh water supplies. The state of California's challenge with identifying new approaches for water resilience.

Desalination is, of course, not new. The first commercially viable reverse osmosis membrane was invented and patented by UCLA in 1960, and the first modern desalination plant in California was built over three decades ago on Catalina Island. But new technological developments are changing.

The conversation about desalination a possible role in the state's water portfolio. Today, I am joined by four other experts, all working on the cutting edge of desalination research. I'm going to invite them to introduce themselves, their expertise and a specific desalination challenge that they're working on right now. Sunny Jiang from UC Irvine, can you please kick us off? Yeah. Hi everybody.

My name is Sunny Jiang and I'm professor at the Civilian Environmental Engineering at UC Irvine. My research focused on what our quality engineering treatment. I also serve as the Associate director for Water Energy Nexus and Center at UCI, and I also affiliated was the and now you will hear that many times today I worked with Inouye National Alliance for Water Innovation as cartographer for Ocean Desalination to Produce Municipal Drinking water. Thank you, Eric.

Great to be here. Thank you, Sunny. David Sedlak from UC Berkeley, can you go next? Hi, everyone. Thanks for joining us. I'm David Sedlak, a professor in the Department of Civil and Environmental Engineering at UC Berkeley and director of the Berkeley Water Center. For the past 25 years, a lot of my research has been focused on potable water reuse and the technologies that are enabling a transformation of our our water systems from being a linear system to being one where we recycle most of the wastewater reproduced in our cities.

As in the last few years, I've gotten much more interested in desalination and I've taken a role in now the organization that Sunny just mentioned as the lead cartographer, which means I was in charge of leading the research roadmap and I'm conducting research these days on brackish water desalination and questions related to treatment of the brine or concentrate from desalination systems. One of my observations from my time working on potable water reuse is that new technologies often undergo a process of legitimization where the public has to make a decision about whether they think it's the right thing to do. And having lived through the legitimization of potable water reuse, I understand the importance of academic researchers, professional scientists, utilities and regulators coming together to conduct research that's needed to support decisions about investments in future water infrastructure. And I think this is a great time to come together and think about the process through which desalination undergoes the legitimization process. Thank you, David. Meagan Mauter from Stanford University.

Can you introduce yourself now? Sure. Good morning, everybody. Good afternoon. My name is Megan Monter. I serve as the research director for the National Alliance for Water Innovation, and I'm also an associate professor at Stanford University and the Stanford Law School Sustainability. My work has focused on water desalination. Throughout my career, working both on new technologies for desalination challenges, including improved membrane design, improved processes for brine concentration and alternative approaches to precision separations in the desalination space, and has further evolved into thinking about how we sustainably incorporate desalination into our water supply portfolios.

I have a special interest in thinking about how we integrate water infrastructure around electricity infrastructure, and I think that that's a key area of importance as we both seek to secure our water supplies and decarbonize the the California surf economy. Thanks, Meagan And last but definitely not least, Reza Lakeh from Cal State Poly Pomona. Can you introduce yourself? Sure. Thank you very much, Eric. Good afternoon, everyone.

My name is Reza Lakeh and associate professor and coordinator of the graduate program at California State Polytechnic University in Pomona. I was formerly postdoctoral fellow at UCLA before joining Cal Poly, where I was researching in renewable energy and energy storage systems. And since moving to Cal Poly as a professor, I started researching in the field of water. We had some efforts on greywater, reuse, decentralized greywater, reuse systems that try to give another life to wastewater that is not very polluted with organic waste. We also recently tried to work on a technology that can convert the unwanted byproducts of desalination into something that can reduce the cost of energy storage systems.

As we will talk a lot today. Desalination does have its own benefits, but it does come with unwanted byproducts that we need to address. Thank you. Thank you. So I'm going to provide a few definitions to get us started and then ask some prepared questions to get our panel warmed up.

And while I'm doing that and throughout the panel, please use the Q&A feature to submit any questions you have along with your name and affiliation. So first, desalination is a separation process where salts are removed from a sealing water source, and this results in two new streams one which is a freshwater stream. The portion of the water that passes through an oral membrane reverse osmosis, and that's typically potable quality and an even saltier stream that we call brine or concentrated brine management is a major concern in nearly all desalination applications. Second, for this panel, we consider both seawater and brackish water brackish groundwater desalination as possible solutions to enhance our drought resilience. I think we all know what is seawater, but specifically it varies in salinity from about 3% to 4% salts, depending on where you are around the planet. And brackish water is water that's saltier than drinking water, which should be less than 0.05% or 500 parts

per million salt and all the way up to the lower end of seawater salinity, rays. As I can get started by just describing how does modern desalination work? Well, as you mentioned, desalination is a separation process in which the water that includes an acceptable amount of impurities, both both organic and non-organic, is either pushed through a membrane by a pressure, pressure driven process or separated by by thermal processes to a flow of water, which is portable. It does have limited amount of impurities and another stream that is going to have all the unwanted minerals and organic content in it, which we will need to safely dispose.

So the problem of disposal of that brine is more obvious if you are away from the coast So near coastal areas, since we have access to a wide body of water which is already has a high salinity but at much less values, we can use that to dilute this water, this unwanted concentrate to levels that doesn't harm the environment. So this is also subject to a lot of debates and discussions in the academic academy or papers that support this method of disposal. There are others that show concerns, so there is no clear indication for that.

But the problem is more clear when you are trying to desalinate brackish and surface water in the locations that do not have access to that large body of water. So if you consider the Midwest of the United States, that is the access to to any body of water. And that area has potential for brackish water. However, due to the absence of this disposal mechanism, the capacity has not grown to the water that it can.

Thank you. That was great. Megan Desalinate desalination is often described as being very expensive. Can you give us a sense of how expensive is it and why? What makes the process so costly? I was muted, sure, I think it's important to think about desalination as part of a water supply portfolio. So when we turn to, say, the city of San Diego and we ask how much are they paying for their desalinated water, it's put in perspective with the broader water supply portfolio, which accounts for the vast majority of the water supplied to that municipality that we can think about all sorts of different water sources that the City of San Diego uses conservation, surface water, groundwater, imported water, recycled potable water, recycled non-potable water, then finally sea water, desal. And so when we think across that cost spectrum, some of those earlier sources I mentioned are going to be lower cost somewhere between 500 and $1,000 an acre foot. And some of those later ones, especially recycled potable and desalinated water, are going to be closer to $2,000 an acre foot on average.

I think it's also really important to understand that a lot of the costs that we're seeing, especially in new bids for desal build, are very dependent on a couple of site specific factors. So especially in California, the two recent seawater arrow proposals are very similar in size. So they're about five MGD, but they are really different in terms of cost. One is at about $2,000 an acre foot and one is about $6,000 an acre foot. And we're seeing that discrepancy because of things like is the land available, How much water transport do we have to do from the desal site to the end use? Do we have to build a long pipeline which is really expensive? And do we have a sort of what's the contracting mechanism? Do we have a build own operate? Do we have a design build? So there's a lot of nuance that goes into the origins of those costs. But I think it's important to understand that in most cases we're seeing desalination really as a marginal water supply that would provide somewhere between five and 10% of a municipality is water source.

And so the costs should be amortized also over that full water supply portfolio and looked at relative to the other sources that are available. Thanks for making those really helpful. Sunny, can you talk about what are the environmental impacts associated with desalination and can they be mitigated and how can they be mitigated? Sure. Well, I would follow up on Megan's side is to energy very expensive. And those I would say the number one environmental issue actually is the energy consumption is the carbon footprint is one.

We use all of those energy to produce water. We generate a lot of greenhouse gas. That's the number one environmental concern. The reason why I'm saying that is because there is no short term solution to mitigate that energy that required to separate the water and salt. So I think we have a little discussion about the technology.

I won't go into that right now, but I know everybody who is interested in desalination heard about those debate about brine discharge and heard about debate of impingement and treatment of juvenile fish and then degradation of ecosystem. Let me address the brine discharge and as you heard from Rosa, already inland brine discharge is a huge deal because there is no safe place, there's no nice place, there's no easy place to put that brine, which is double the amount of salt that exist for seawater. And there's a whole bunch of other chemicals in that You don't have a place to put it. My expertise is on more seawater desalination. I do understand and there's a lot of environmental concerns about brine discharge and there are some permitting problem with discharge of brines through ocean outfalls.

It is true if you discharge twice as concentrated salt in back to the ocean without any engineered technology, you may cause the so-called inversion of the density so that the brine will settle on the sea floor and then do not mix well with the upper portion of the ocean. You cause a zone that is very salty. But now we have the technology. We can mitigate that by using the diffuser technology. They required this long perforating pipe and going into the ocean before new discharge. The hydrodynamic mixing between the salt water and the ambient water is continues as the water piping out into the ocean.

Such mixing would change that the salinity dramatically and there is many research had been done in the recent years to look at the brine discharge, to understand the ecological impact cost that I know a lot of this our nation, especially ocean desalination people, are interested in the coastal environment. I just came back from University of Hawaii actually, and that there is a big ocean out pipe is not for desalination but for a power plant cooling that is a famous scuba dive and snorkel site because as a pipe where you have the it's called the electric power plant site has tons of fish. If you want to see a fish, you go there to scuba dive to snorkel. And we worried about the thermal contamination and we're worried about all the power plant cooling water to damage the ecosystem. And as long as I see there wasn't any Bering land in that area, there is the most amount of fish. So that was my answer about brine discharge.

And there is mitigation technology as long as our permitting required those diffusers and that we are able to overcome the old ocean discharge of. Right. But without the diffusers. Yes, those are environmental impact about impingement and treatment. And maybe people are heard a lot about sucking up the baby fish, why you are pulling in sea water for desalination. There are also technologies and then develops to deter the fish from going into those vans and there is also a lot of video recording with the online cameras to see how the fish behave around the the intake of the area of the desalination intake.

So I think a research are in there technology are there to help us to mitigate those environmental impact that many people are concerned just because in the early phase of the ocean desalination, we are not truly understand those technologies and those impact yet. And the the activity from the environmental group has really promote such development. I will stop there and move back to you, Eric. Yeah, that was great.

Thank you. So I think everybody Oh, David, one last question I'd like you to take a shot at. So how do you see desalination fitting into the broader portfolio of water resilience strategies for the state of California? Thanks, Eric. I think we've already heard a little bit from Megan about this idea that desalination is one part of a water portfolio.

And I think the best way to think about that water portfolio is to consider the contribution that desalination currently makes to California's water systems, the likelihood that it will grow in the future and the importance of desalination in the places where it's actually been implemented. So starting with the current state of desalination desal, the nation is primarily being used in the urban water sector, so it's being used for cities, usually cities along the coast, but some inland cities. And currently our seawater desalination plants produce about a little less than about 0.1 million acre feet per year. So you hear this, you never get a million acre feet per year.

To put that into perspective, all of the urban water use in California is about 7 million acre feet per year. So it's a little less than it's around 1% or even less. If all of the proposed desalination plants that have been floated in the last decade were to be built, that would almost double that. So it would only be about 2%. Looking at brackish desalination, the use of desalination in an inland community, which is increasingly common in southern California and some dry parts of the Central Valley, it's about half of what current desalination is today about 0.05 million acre feet per year.

So this is a relatively small amount and if we compare it to the amount of water, for example, needed for agriculture, which is, you know, upwards of 30 million acre feet per year, it's extremely small. So why are we talking about desalination? Why all the discussion about desalination? Primarily because if you don't have other sources of water, desalination can be a lifeline. And so we've seen in places like Santa Barbara where they recently built the desalination plant because they had junior water rights and we're kind of at the end of the pipeline with respect to the state's water supply. Desalination was incredibly important because it provided some certainty that the city could get through extended periods of drought. Likewise, in smaller cities like Fort Bragg and Cambria, where desalination plants were instrumental in helping the the towns and cities ride out the last drought. And so where we see the importance of desalination for California's water portfolio is in the places where they're either junior water rights and no other good sources of water that haven't already been exploited, where conservation has already been implemented and where there are limited opportunities for water recycling.

And so in the portfolio, there's a real desire among these communities to have desalination as one of the tools in their arsenal for consideration. That was really great, David. I think we're all warm now and I think I'm I'm going to go to some of the Q&A questions that have been submitted.

The first one that's up is from Carl Longley from the California Water Institute at Fresno State Hydro. He asks, What are your views on the future of inland desalination, particularly on brine disposal options? I'm going to open it up to the panel. I'm going to say maybe let Megan speak first and then whoever wants to jump in afterwards, feel free. Great. So, you know, I think that the future inland desalination definitely depends on a future innovation in reducing the cost and energy intensity of that concentrate stream management.

There are some places where there is easy disposal of that concentrate, and oftentimes that is in subsurface wells, basically injecting it into deep strata. And that works in places like Texas. And there's a lot of brine concentrate that is injected in Texas and in other places where you have good injection or good geology for injection.

That is not universally true across the state of California. And I would say that a key and very important research focal point is in developing brine concentration technologies that help us efficiently move from the roughly 50,000 parts per million TDs or 50 grams per liter concentrate of the concentration all the way up to something that approaches either a saturation point. So a brine saturation where you're starting to go crystals or all the way up to a solid product. There's a lot of potential pathways to get there.

And the National Alliance for Water Innovation, where I serve as research director, which is housed at Lawrence Berkeley National Lab and supported by the U.S. Department of Energy, is very focused on this question of how do we develop new technologies to efficiently help us concentrate brine, but also derive value from that concentrated brine. And so that brine has the potential to become feed streams and other industrial processes and has the potential to help us source specific elements that that we may be interested in. And I think broadly, we need to be looking at place based solutions for brine management that account for existing disposal pathways, existing subsurface geology and existing markets that a concentrate might feed into.

I'll pass that over to David. Do you want to go for it? Yeah. So first. Hi, Carl. Nice.

Nice to have you with us here today. I just wanted to mention one more option that may enable inland brine desalination, especially in California. And those are brine lines. So there is a pipeline which carries water from the Inland Empire to to a discharge point off the coast of Southern California. And it has been instrumental in enabling desalination in that part of the state.

And as you're aware, through your work with sea salts, there's been consideration of the idea of brine lines in other parts of the state to take advantage of the idea that once you concentrate the salts, you might be able to move them long distances. And so I think that in addition, we may see opportunities, especially in the populated parts of Southern California, to think about how we can more efficiently use our existing infrastructure for this. For example, here in the San Francisco Bay Area, we have the Livermore Valley where they have a long pipeline which takes their sewage effluent all the way to San Francisco Bay for discharge.

And part of the reason was they didn't want to leave the salts from the sewage effluent in the basin. That is slowly turning into a brine line as more and more desalination happens in the Livermore Valley. So there's another opportunity here to think about some of our infrastructure that lets us use surface water disposal of these brines after appropriate treatment to to enable an even less expensive way of managing brine. I'll just add to that and say that these brine lines are increasingly volume limited though. And so if we're going to make good use of the existing infrastructure we have, it's actually going to require a combination of concentrate technology. So pushing in that brine to higher and higher concentrations and thus reducing its volume, as well as leveraging new infrastructure and potentially building new infrastructure.

As David mentioned. Reza go ahead, yeah. I think you're still muted. You're on mute yourself.

I'm sorry. So regarding that pipeline that delivers the brine in Southern California, I know that the cost of using that is a burden for desalination plants. And also, you know, regarding the disposal of the brine in areas that is far from the course inland desalination, I think development of technologies that, you know, desalinate water to almost, you know, solid zero liquid discharge technologies, they can be very important to extract more water and at the end to reject out that process is a solid that can be repurposed in different applications for energy storage or for construction as an example.

The other topic I wanted to briefly touch on was about the safeness of disposing of brine in the ocean. I know we talked about that. I think this really depends on a variety of reasons because we're talking about the biological ecosystem and the low cost salinity of water and the design of the diffusers may impact the, you know, the outcome of our design in the long run. So if you look at the research, the studies on diffusers, many of them or many advanced advancements are happening in the current decade and this may or may not be enough time for an ecosystem to respond.

It's not. It's outside my expertise, but it kind of bothers me that we don't know enough about this topic. I think there is a I know in Southern California, the two brine lines we call sorry lines are a great asset. They're also either fully or almost fully allocated. So there's not a lot of room for additional new brine sources to be fed in and safely discharged to the ocean. So that does it solve the historical problem, but it's not the solution going forward.

And I saw a map recently of what Southern California looked like when those pipelines were installed and the population was a fraction of what it is now. And it was mostly dirt and undeveloped land, but the pipes were laid through and but now there are neighborhoods and business districts and industry all all surrounding them. And so to do that again would be almost incomprehensibly expensive. It just unbelievably expensive. So but in other places, you know, there may be opportunities, as David said, to to to build new pipelines to help manage. I see.

Jim Holley from Lawrence Berkeley National Lab. Hi, Jim. As I say, can you discuss the potential for small scale modular designs and their applicability to smaller communities? So I think I'm going to ask David to speak first and then again, whoever else wants to jump in, feel free. So one of the really exciting places to think about desal and having an impact is on small communities where which are among the most vulnerable here in California and pretty much around the world. So when you look at California, there are close to a million people who are relying upon wells who are at risk of running out of water during droughts or currently being accessing water that's contaminated with constituents that are hazardous to their health, like nitrate or arsenic. And desalination is a technology that has is inherently modular.

The membranes that are used in a large seawater desalination plant and the membranes used in a brackish water plant are very similar to the ones that are used in a small scale system that could be applied at the level of a cluster of homes, a small community or even an individual. Well, and so the historic challenge in doing that, there have been been a number of them, and I don't know that we have time to go into all of them in detail. We're starting to address some of them now, but being able to make these modular systems autonomous, being able to assure that the maintenance is simple, that they're safe to use, and that they're also not rejecting large quantities of water. So historically that under the sink, reverse osmosis units that people use are operated at at very low water recoveries, which means that in some cases for every liter of water they produce, they're wasting a liter because they're they're not run up near their operating limits because it's hard to add and scale ends. And there's a lot of concerns about possibly fouling the membranes. So there's currently like right now, you could deploy a small scale desalination system that relies upon reverse osmosis or an another technology to a household well or cluster of homes or a small community.

They just happen to be relatively expensive. But by on the best ways of using sensors, changing the materials used in membranes, working on pretreatment, etc., we think that there's a path to lowering that cost and making it the go to option. When we think about protecting communities from from threats of water contamination and also being able to access brackish water resources. And I think there are a lot of people in this panel who probably have things to add to that. Yeah, maybe I'll just jump in and say that the California Department of Water Resources has also been very pivotal in helping to support Maui's efforts to pilot some technologies and small inland communities, especially technologies that aren't necessarily membrane based.

So some of the some of the water contaminate issues in these small communities are not exclusively issues with total dissolved solids. They can be issues with nitrates for instance, or with arsenic. And so now he has been piloting and will begin to pilot some technologies that are really designed to be small scale systems that serve communities and may or may not be membrane based.

So you're not generating the same degree of concentrate that needs to be managed in those inland communities, but are really focused in separating the ions of concern and doing so through an either sorbent or electrochemical based processes. But really good points. I see Sunny has her hand up, go ahead. Yeah, I see. The question becomes a question also not only for the small packaging system, also asking about renewable energy, how the renewable energy can be integrated into the small plants and packaging plants. I think actually that is a really great question and great addition to the small package plants.

And so you reduce the transport of energy and I don't know if there are any studies have done if there is renewable energy for small package plans or household plans. Virgin Islands has a lot of a small desalination plants and they they none of them are around renewable energy. But I know very large desalination at these desalination plants in Perth, Australia, they are fully a lot of them are run on the wind power or renewable energy.

So so I would say definitely combining renewable energy with a small plants and definitely is a is an interesting area. I don't know how much exploration we have done. So yeah, those are also good points. So I think I'm going to go to the next question and apologies if I get the pronunciation wrong, but Chris TRANEL from the California Department of Water Resources says the governor's recent water supply strategy directs state agencies, Among them, the Department of Water Resources, to consider avenues for improving coastal desalination permitting processes by I think we mean making it take less time and be less expensive to obtain a permit. Any thoughts on how the technologies you're all working on could help shape that conversation? What technology is coming online that we should be considering as part of these conversations? Yeah, go ahead. So I just just kind of continues with what Sunny discussed about the importance of renewable energy for the future power supply.

So as we know, California 2045 to run fully on renewable energy around the power grid, on very doable energy, and that will impose a significant amount of demand and on energy storage technologies because of the intermittent nature of renewables into power grid. This I think, has a huge potential that can be tied in to water desalination because we can consume the energy at the times that is not really needed by other sectors so that we can generate the water for for our applications. Hey David, yeah, please go ahead. I think that the question of how to streamlining the permitting process is an important one.

But I also think that getting getting it right in these early desalination projects is really important as well. You know, I don't work directly in the permitting process for ocean desal plants, but as an observer from the outside, it feels me a lot like the early days of potable water recycling, where every single project is quite different from one another and undergoes a lot of scrutiny almost at the level of National Academies panel study, and that those take long times. And there are differences of opinions and it does delay the process. And so one of the things that CCST and the state might want to consider is actually asking some outside scientists for advice on some of that technical issues that seem to be tripping people up, because it does seem like every project feels like a PhD dissertation or even more than that. And it seems that once the state is permitted a half dozen or a dozen projects, that the permitting process is likely to go a lot faster.

And so there needs to be perhaps a strategy that sees additional resources coming in to the the science and technology discussions with the promise that once we've resolved some of these key permitting questions, that applicants will have a better idea of how California views safe and acceptable seawater desalination. Yeah, Thank you. So there's a question from Keith Cialino from the State Assembly's Water and Wildlife Committee. Will the cost per acre foot come down with technology advancements and the use of renewable energy technologies? In the short term, what cost per acre foot might be achievable? And a related question from Sean and I from the California Energy Commission. Commission.

Is there a preference for solar, solar thermal, geothermal, offshore wind in terms of integration with renewable energy technologies? So how do how does the cost curve look near-term long term? And and how does integration with renewable technologies influence the cost curve and which which might be preferred? Yes. Like Meagan wants to to jump in here. Go ahead.

I have a couple of thoughts on that. You know, we've actually tended to see desal get more expensive in California and less expensive in California. And a lot of that is permitting. Very little of that is actually energy costs, even though energy costs are going up. The the cost of energy relative to the capital costs are de minimis. You know, we're talking somewhere between 25 and 35% of your costs of running a desal plant.

And even that depends a lot on, you know, what is your source and what are the overall kind of intake, permitting, piping, etc., costs that just are part and parcel of a lot of these big projects? I think that you're going to see costs come down when a couple of things happen. The first is when these especially small scale plants become really basically like, you know, very modular in their technology and and very uniform in their deployment schema. I think there's a possibility of really moving towards package systems that all look the same and kind of get dropped in to work for a whole host of different water supply systems. So cutting out a lot of the design costs and also seeing the economies of scale in manufacturing and deployment is going to really help drop some of those costs. I think that for the the large scale package systems, a transition to renewable energy is actually an opportunity.

What we're seeing is that a lot of these existing facilities are signing contracts with demand response providers to ensure grid stability by curtailing plant operations. And so they're deriving pretty substantial revenue on a yearly basis, usually equivalent to about a month or two months of their total energy costs to provide demand response services in the times in which the California grid is really stressed. So that might be six or eight times a year. It's not every day.

But the truth is we're not really designing for that right now at our plants. And I think there's an enormous opportunity to think about ways in which we are actually building flexibility into these desalination plant designs, potentially allowing them to flex their operation much more than 6 to 8 times a year, and instead really flex their operation, if not on a daily basis, then then several times a week, the value add to the grid, especially in displacing the need for things like battery storage, is tremendous. And I think there's an opportunity in the research arena to better articulate what that value is and then also better design plants and standardize the design of plants that really allows for high intermittency operation. So smart integration with the grid and the water systems working with the power systems in concert seems like a win.

I'm going to ask maybe Sunny and Razor if they see any new technologies on the horizon, either new water desalination technologies or energy technologies that can further help bring down the costs. Should I go first, Reza? Yes. Well, yeah, well, you know, my expertise is mostly ocean desalination, so I will speak in that friend about future technology to potentially cut down on the cost. Well, if I focus on the technology part, I do feel that membrane technology have changed our desalination dramatically thanks to people like Eric who your your your moderator here and his membrane technology has dramatically reduced the energy costs of separation of the water. And over the past ten years, we are almost reaching the thermodynamic limit of separating salt and from water and then so that technology innovation can dramatically cut down the cost because of the energy of the current system, I would say not the membrane technology, because we are reaching that limit.

But there is other area that we can looking into. So the desalination costs increase. Bad desalination plan is about five times as high as in the plan in Israel. And there is many, many factors in there. You heard from Megan from the very beginning about desalination. There are a lot of those and nitty gritty details about location, about transport.

And then in that technology, friend, I do feel like pretreatment to protect those membranes, to enhance the operation and that helps and the permitting process that in the sense of what Megan just talked about, making those small package planned and dropping into the location that need water, that really the optimize the process, the cut down the permitting and all the other paperwork ahead of time, cut down the cost. And then can that same process be the similar process being applied into the larger ocean desalination permitting process that's also potentially cut on the cost? So cause is a very complex structure, not only technology, but for the technology of brand. I do feel like the membrane technology maybe have a little bit room for improvement, but maybe the pretreatment or post-treatment resource recovery potentially offset the costs of desalination. With that, it back to you. Right.

Reza, any final words on this subject? Yes. So I am personally excited about zero liquid discharge technologies that I see becoming more and more available and using different technologies, mostly thermal driven. So thermal energy to use for that final desalination, a step to convert the stream of the dispose the brine into a solid stream and a liquid stream. And there are a bunch of applications currently being identified for the solid salt, including for construction, for extracting minerals and all that. The other technology which I see not very growing in the US but internationally it's seem to be picking up is solar thermal desalination in which the solar energy is harvested in the form of heat and is used for thermal desalination.

So that technology in the US I don't think is picking up. But worldwide it is a subject of new advancements. David, go ahead. Yeah, I wanted to maybe challenge the questioner a little with the concept of thinking about water in its cost per cubic meter, acre foot, the the true value of seawater desalination and brackish water desalination in some degree is its reliability. So during periods of extended drought, that water is much more valuable to you than water that you're storing in a surface reservoir or stormwater that you're harvesting from from a river or something like that.

And then the other advantage of desalination is comes with the potential of blending. So you're producing water that's extremely clean in some cases by blending it with water that is already slightly salty or has slightly elevated concentrations of organic matter which would form disinfection byproducts in the water system, you can actually access water that is currently off limits without any additional treatment. So there are opportunities when you have desalination works, increased drought resilience and also using that extremely clean water to improve the overall quality of water in in a larger water system. And here in California, many of our existing water systems need that low salinity water to improve their quality and esthetics and and overall composition.

I'm going to add that in some places like in the Middle East, for example, where they have a lot of sea water and sanitation plants that folks are already exploring the idea of product sizing the brine or something which can be selectively removed from the brine of a much higher value like magnesium or a bromide for industrial applications, or even selling a clean sodium chloride brine for the production of chlorine and caustic soda or things like that. And in many cases, not every case, but in but in many cases, you can actually make more money from selling those harvested products that you harvest from the brine and pay for the whole water treatment operation and and with profit on top. So I think some of the future direction is going to involve what some people refer to as valorize ing what is traditionally viewed as a waste. Squeezing as much clean, fresh water out as we can and trying to extract value from high value constituents that may exist in that concentrated brine stream. I think we're we're pretty close to at a time. And I think, you know, one last question for each panelist.

Is there like a technology that you're just absolutely excited about or do you have a recommendation for the state specific recommendation about desalination? Razer, why don't you go first? Yes, I think as we discussed offline, we definitely need more research on the effect of coastal brine disposal on long term studies to look at the effect of this in in longer times. So my advice for the state is allocating funds toward this good. And I also suggest it's like a lightning rod. Just 20, 30 seconds, Sunny, go. I had to find my button to unmute. Well, if I have to recommend to the state, I will say, well, you wanted to you don't want a desalination going to come because you're going to run out of water.

And then so I would ask California to seriously consider that streamline the permitting process and a building the expert rather than making you know Dave mentioned that this is of became a argument or wisdom became a dissertation and we don't have time and to California need to put their effort and that and have streamlined that process to make things happen. Meagan Um yeah, I guess I would just encourage us to think about desalination more broadly than just seawater desalination. There are lots of impacted water supplies that are not available to us for consumption and are productive agricultural or industrial use because of some specific contaminants of concern or because of some specific ions that are at concentrations that don't really allow for their use.

So I think we need to be thinking about desalination as serving a broad set of nontraditional waters, and we need to be thinking about those nontraditional waters that's really helping to provide California a resilient water supply portfolio. Thanks, Ben. All right, David, last word. Yeah, California need to take this issue of legitimization more seriously on one end of the legitimization spectrum where the critics were.

Listen to where the science was done and the regulation was built in a way that address those issues. We have potable water reuse, which is going gangbusters in the state. And on the other end we have nuclear power, which is shutting down at a time when the state might have been well-served by having it, and those can be traced to a lack of good stewardship by by the legitimization process. And so we're at a critical point for desalination. And if we get it right, this could be something in our portfolio going into the future. That's great.

Thank you, David. So we've come to the end of our time and. I'd really I'd like to thank the panel for such a great conversation and the audience for for a great questions and CCST for putting this event on and now I'm going to hand it back to Sarah to to close up. Thank you.

Thank you, Eric. And thank you very much to our panelists today for sharing your time and your expertise. You covered a lot of cutting edge information.

I learned a lot. Thank you to our team at CCST for coordinating this briefing and for Brie for jumping in to finish my introduction today. And of course, thank you to everyone who joined us for any part of our Science and Technology Week. This week, in addition to this briefing, you all provided. Some excellent question. If you'd like to watch Briefing again or have a colleague who was interested but couldn't make it, it will be posted on our website along with the one pager and contact information for experts you heard from today.

Thank you. Have a really good day.

2023-02-24 11:14

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