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September 24, 2024
The Gila River, which flows through New Mexico and Arizona, is the site of the first operational solar covered-canal in the United States, and will provide renewable energy to the people of the Pima and Maricopa tribes. This pilot project, also called the Casa Blanca Canal solar project, received nearly $6 million in funding from the Inflation Reduction Act. For this week’s episode, EESI Policy Associate Molly Brind'Amour joins President Daniel Bresette to speak with George Cairo, the head engineer for the Casa Blanca Canal solar project, about the benefits and challenges of canal-based energy systems.
Show notes:
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Episode Transcript:
Daniel Bresette: Hello and welcome to The Climate Conversation. I'm Dan Bresette, president of the Environmental and Energy Study Institute.
Molly Brind'Amour: And I'm Molly Brind'Amour, Policy Associate here at EESI, and I'm filling in for Alison Davis, who's away from the mic this week.
Dan: Thanks for stepping in, Molly. We're gonna have fun. Great to have you here. How have you been doing?
Molly: I'm doing great, and I'm really excited today because I get to join the podcast for this episode. In particular, we're going to be discussing the Gila River, which is also the topic of one of my favorite articles that I've written at EESI so far, and also one of my first articles so kind of nostalgic and really reminds me of the really great stuff that's happening out there. The link to that article will be included in the show notes for anyone who wants to give it a read. But the TLDR is that many people support protecting parts of the Gila River, which flows through New Mexico and Arizona, under the National Wild and Scenic River system. A designation like that would not only help defend the river's wildlife and ecosystems, but it would also uplift the surrounding Hispanic and Latino communities that hold the Gila River in really high regards for cultural and historical reasons.
Dan: The Wild and Scenic Gila River is still awaiting its official designation, but that's actually not why we're talking about it today. The Gila River is back on our radar screen because it is the site of the first operational solar covered canal in the United States, and it will provide renewable energy to the people of the Pima and Maricopa tribes. This pilot project, also called the Casa Blanca canal solar project, received nearly $6 million in funding from the Inflation Reduction Act, which was awarded to the Gila River Indian Community in December of 2023. It's always so great to hear stories about how the IRA is improving the lives of people across the country, and solar canals are a really exciting and innovative technological solution, because they offer a lot of advantages over land based solar power, like slowing down water evaporation, which could help alleviate some of the water shortages we often see in the American Southwest, but these canals haven't really taken off in the United States yet because they're more expensive and difficult to install than traditional solar farms.
Molly: Our guest today is George Cairo, the head engineer for the Casa Blanca canal solar project. He's the principal engineer and founder of George Cairo Engineering, and he has more than 32 years of experience in agricultural engineering, water resources engineering, and conveyance planning, design, and construction. George is also the president and founder of Cairo Canal Solutions, Water Xience, Zanjero On-Farm Irrigation Design and Supply, and several other water business ventures. He's the District Engineer of record for several irrigation water and power districts in Arizona and California, and is recognized as an expert and leader in the protection and transition of irrigation districts, agricultural to urban land conversion. George, Welcome to The Climate Conversation. Thank you for joining us today.
George Cairo: Thank you for having me. I appreciate it.
Molly: So my first question, what is a canal energy system?
George: A canal energy system is a concept that was hatched and thought of by Water Xience. Water Xience’s objective was to bring solutions to the water and energy nexus and look at a sustainable, circular bio economy, and how we could reuse something that we already have, so that we have multi use and still answer the question of water and energy and the issues and challenges that we face there. My background involves working in agriculture, and I've designed literally thousands of miles of canals in my career, and if you looked at a canal corridor, in other words, these canals have already taken a strip of land, and they're utilizing it at the moment to convey water, and that water is vital to everything here, especially in the desert Southwest. So when we looked at that, I got the idea that instead of just a canal, we should look at that corridor and look at it as a canal energy system, not just water conveyance. And so by an energy system, we look at, what can we harvest from that corridor? And that could include solar energy that's over the canal. It could also include terrestrial based solar, that, you know, you might have a wide strip of land, not such a narrow land, so you could take advantage of both the canal and the land adjacent to it that's already been disturbed. We also look at hydrokinetic, in other words, could we put turbines in the water? We look at the possibility of wind energy and even bioenergy. And when we look at a corridor, we look at it as a canal energy system, and see what can we harvest from there?
Molly: That's amazing. I really love that idea of a canal energy system. So with thousands of miles of canals, my question is, what are some of the technical and structural complexities that come with installing solar panels over canals compared to, say, over land?
George: So one of the main things is, you have to remember that a canal is an active system. In other words, whatever you do along that canal, you cannot interrupt its intent, its purpose, which is to serve irrigation water. One of the challenges is that aspect that you're typically going to be working around a system that we call in service. It's going to be delivering water. So any design and any construction has to be done while the canal has water in it. And that's kind of a unique challenge. And you also have your roads are generally not that wide, and you have to have a unique approach. And you really have to look at how you're going to construct that system. So those are a couple of the things that happen there. And then you also have to look at your region and where you're looking at installing this. And what I mean by that is, for example, in Arizona, our main design factor that affects the design of the structure is wind. We get what they call the monsoon, and you get these wind blasts. And so our design criteria here in the desert is, for example, 90-mile plus wind. And so you have to design structures to withstand high winds. If we're doing something in California, for example, you have seismic challenges, you have to worry about earthquakes. And really you're going to have different challenges depending on where you are. But mostly the complexities have to do with engineering something and designing taking in mind that the irrigation district has to maintain service, you have to service your crops. You have to service your deliveries while you build this facility and maintain it in the future.
Dan: This is so cool, George, this feels to me like something that was always a good idea, and I'm glad it's being done now. So for the renewable energy, obviously there's benefits of that, but what are some of the other benefits of solar canals?
George: You know, you're going to hear the argument of A versus B, terrestrial versus what we're doing here, and when you start the ledger, you start with cost, and these projects, when you start from a capital cost standpoint, are going to be more expensive than a terrestrial. But then you start to look at all the benefits. So you start to tally things up, to answer your question about, you know, what other benefits come from spanning canals with solar. So one is the multi-use of that existing easement. In other words, you're getting to multi-use that land. I don't have to lease any land or disturb any land that could be used for any other purpose. So it protects land interest. For a point of reference, for example, if I cover one acre of canal with solar panels to accomplish the same amount of coverage on a terrestrial system, it takes two and a half acres, so I need to disturb two and a half times the land to accomplish the same power generation. Some of the other benefits is, the canals are linear, and so you can distribute power on the shading of the canal, the solar panel shades the canal. And so what it does is it doesn't allow solar radiation into the water, and so it reduces the growth of algae. So algae is a big operation and maintenance cost for a water organization. So by reducing that, you have this reduction in O and M, cost and activity. To give you an idea, some of the tests that have been done currently are showing at least an 80% reduction in algae growth. So that's very important, algae growth is also tied to pre-treatment cost. If you're delivering to a water treatment plant, the big cost is pre treatment of algae before it goes into their filtration system. So there could be a big benefit there. And there's also food safety, which is really important. Another thing is it obviously is going to shade the canal, so there is water conservation through evaporation reduction. And, you're looking at numbers that could be 50% and higher. And to give you an idea what that means here in the desert southwest, depending on where you are, you could evaporate anywhere from seven to ten feet. So for you to understand, if you have a swimming pool that's ten feet deep, it would evaporate dry in one year. So I can save half of that or more and reduce that evaporation. So when you look at that across the length of a canal or an installation, it starts to add up, so it's a huge savings. There's also what we call the thermoelectric offset. That's something that people forget. In other words, if I replace another source of energy with this green energy, these other sources of energy all consume water, so by offsetting that generation with this type of green renewable energy, not only do I have water savings from evaporation, you then add the water savings from the thermoelectric offset, and so it's a gain-gain. Another benefit is normally because our canals are near power lines, most water districts tend to be water and power, so your connectivity tends to be close. And the benefit there is that if you think about where terrestrial solar projects are installed, they're generally where people can't see them, they're out at a distance, some open land, and then I have to transmit that power to where I'm using it. And so there's what you call transmission losses, and those losses could be in the neighborhood of, say, seven percent, so now you have more power being generated because you don't have those losses getting to where you're going to use it. Another thing that's beneficial is, because you're shading the canal, you end up creating a micro climate, right? And so you have this micro climate of humidity under the panels, and you also are reducing reflective energy. What that means is the panel is operating at a lower temperature, and so it improves its efficiency. You can gain two to three percent depending on the installation and other factors, but your panel will be a couple percentage points more efficient every minute of every day that you're collecting solar radiation. One of the things that we find as a benefit, and is driving some of our projects, is that a lot of these irrigation projects have to pump water out of the ground, and that's energy consumption, and we're able to offset and use renewable energy with these systems to offset groundwater pumping. In some cases, it could become a secondary source of income for the district. There's also good public relations, it really helps when a water district or a solar power developer can say, look, we aren't taking land out of production. We're not affecting agricultural lands. And so there really is a lot of value with the agricultural community in these rural areas that tend to maybe resist. And one of the other benefits is, you know, it's tied to the future of what happens with these systems. In other words, what other things are out there that you can do with some of this energy that's ancillary to what we just discussed? When you really start to add all these components up, and you compare terrestrial versus this concept, I think you'll be surprised at the outcome, not only economically, but also when you talk about sustainability and water scarcity and all these other things that are important to us.
Dan: That's incredible. George. I mean, I think like evaporation, yes, that seems like it makes sense, but so many other really good points, seems like it would be great if we could do more of this. So I'm curious about how systems like these canal based solar power installations, how could they benefit the electric grid, and are those benefits, benefits that would scale as these types of installations are scaled?
George: Yes, I think that when you look back at the development of the West, and I'm focusing here in the desert southwest, but this story repeats itself with any other water development in America. So most of our water districts, they're tied to dams. They're tied to water supply, and there's also an energy component, and so these canals really can favor that, because they're distributed, you're able to develop energy all along the way and use it where you need it. And so that really helps the distributed energy challenge that currently exists with the current distribution system that we have, as far as power out there.
Molly: You're really selling me, George, I think these canals sound amazing, and I think that they could be a great fit for a lot of areas. But I guess I'm curious, you know, what is it about these solar canals that make them a really great fit for this Gila River Indian Community?
George: So when we talk about the Gila River Indian Community. I think that there's a couple things that really stand out why they're a really good fit. One of them is that the Gila River Indian Community is really connected to the municipalities here in central Arizona and to the Colorado River. And so anything that we do that benefits Arizona actually benefits the lower Colorado River region. I think, on top of that, Gila River is a client that has always been kind of a leader, and they've passed a resolution, and they've decided to be blue-green. They want to have a blue green economy, a circular bioeconomy. And they want to be carbon neutral, and they mean it. And so that's wonderful to have a client like that. It's a large reservation, to give you an idea, they're about 212 square miles. So it's a big geographic area. And across this expansive area, there are many, many miles of open channel canals, right? You're also in a geographic area that's in a high solar radiation area, here in the desert, and so you got all the variables there to be able to develop these types of projects. It's a rural area, and so to be able to distribute power for the different areas of the community is important for these types of systems. And we also border the big cities, so we're able to connect. And so to give you an idea, we have a lot of interest in some of these projects, and we have players like Intel and others that need a lot of energy, that are looking for green energy and partnerships. And because of that, because of the water, the land, the energy, and really the Gila River and their mission, I think it makes it a win win for everybody and ideal.
Molly: That's really incredible. And I think that's just a perfect example of seeing these in action, benefiting everyone. And so I guess thinking about your work on this, I wanted to know if you have any lessons learned that you could offer to the other engineers who might be working on solar canal projects in the future.
George: There's a couple things. First, anybody that is looking at this, I suggest that you have someone that really understands the canal environment, and so you want to have engineers involved that understand canals, and it goes a little beyond that, because every water district kind of has their own culture, right, and so they like to do things their way. And so an engineer needs to understand, not only is it a canal, but this canal is operated and maintained by a certain organization the way they like to do it, and with the type of equipment that they currently own. So we engineer to that agency's equipment. I engineer the weights and in the physicality of the system to match their equipment. You gotta get buy in, because now someone has to operate and maintain something, and it's changed. It's different. So you’ve got to kind of never forget the end user, and the purpose of the facility is to convey water, not generate energy. And so I would advise anybody that's looking at this concept or designing this concept to not lose sight of that. The other thing is, these systems are very exacting. The system that we designed, which is patented, and it's been engineered by George Cairo Engineering Tectonicus, and it's developed by Water Xience out there. This system, it has pins and it pivots. So, in other words, we can unhook it and we can articulate it. We can lift it up from one side and give you access into the canal. Or we could disconnect it and take a whole frame and just set it aside. So if somebody else is engineering the system they have to understand to build it, you're talking about very tight tolerances. And there's an art to being able to engineer it so that it can be constructed. That's an engineering challenge, right? I can have all kinds of ideas, but if it can't be built or built efficiently, it's not a very good idea. So we've learned in the process through the design of several systems that you need to really consider the equipment that the water agency has, and also the constructability, because you're talking about putting foundations in at exact dimensions, and you’ve got to do them while there's water in the canal. So you can't measure across, and so, so there's some unique challenges there. And then the last thing would also be, remember the region where you're designing, because if you're up in Colorado, I've got to deal with snow and cold factors. If I'm in the desert, I've got the windstorms. If I'm in California, you've got earthquakes. So these things may sound basic, but they are little cliffs that people that are not experienced could fall off.
Molly: Absolutely and I really like what you said about buy in. At EESI, we're always thinking about community buy-in. It's essential. And another really important aspect of buy-in is actually government buy-in. And so we were wondering, how did funding from the Inflation Reduction Act fit into this project? What was its impact?
George: I think the bottom line is, the impact was that the Inflation Reduction Act funds actually allowed the project to move forward. It really was the last push that allowed us to go forward. You know, we had this vision. The governor of the community wanted to be the first in America. He wanted to lead, he wanted to set the standard in Indian Country and give people something to believe in. And so me and Governor Lewis, worked together, and were committed to making sure that this would be the first project that was designed and constructed for a solar over canal, the first canal energy system in America. And in fact, it became the first in the Western Hemisphere. And the money that we received through the Inflation Reduction Act was critical in making this happen. So anything that can be done to provide more support for this concept and to develop more canal energy systems, is just the right thing to do.
Dan: This is great. George, this is so interesting, and it comes through so loudly and clearly that you're very proud of the innovation and your work on this and the project itself. But I'm curious, we never met in person, but you strike me as the kind of person that always has a lot going on. So what other solar over canal projects are you currently working on?
George: So right now, we're doing a number of things. You know, we, along with Tectonicus—Tectonicus was able to obtain Department of Energy grants, competitive grants, and that's how the patent was developed. And we also have another tool that's being developed and will be patented, and that is a GIS-based tool to do feasibility studies. In other words, we have a tool where we're able to come out and quickly evaluate a canal alignment, look at its physical location, elevation, solar radiation, geometry, all these factors, all these variables, and we're able to quickly determine and optimize the system for that canal corridor, if you will. So we're doing a lot of feasibility work, and we're also doing some other design work. There at Gila River, there's a second project that's called the Level Top Canal. So the Level Top Canal is larger in span than the Casa Blanca Canal, and so what's good about that is we now will have two systems, a smaller and a larger that can transfer to other canals in the community. And so there is one project that's been engineered. It's called the Level Top Solar over Canal project, and that project is going to start construction in probably 60 days. That project also received money from the Inflation Reduction Act, but that money was funneled through the U.S. Army Corps of Engineers. So those two projects are there at Gila River. We're also designing another system in Buckeye, for the Buckeye water conservation and drainage district. That project is unique, because that is going to be the first canal energy system in the world that's a dual energy producer. And what I mean by that is, that project will have solar over the canal, and it will also have hydrokinetic turbines in the water. So we're going to have two sources of energy, and we actually recently added a third because we have some land adjacent to it, and we're going to combine some terrestrial with the solar over the canal and the hydrokinetic and so that's being done by Buckeye. And going back to the Inflation Reduction Act, that received money also from a grant from the U.S. Bureau of Reclamation that's funded by that act. So that project is moving forward. We're looking at a feasibility study, hopefully with the Imperial Irrigation District. We're working through some ideas there, and hopefully they will engage. We're looking at a pilot project with the Salt River Project here in Phoenix. Salt River Project is looking at the concept, and we're wrapping up a thirty percent design so that can be considered, and they'll make a decision if they want to move forward with full design and construction. And we have several others that we're looking at. And so we're really happy that the interest and the concept is gaining traction, and we think that it really has a place here in sustaining a circular bioeconomy here in the southwest and abroad.
Dan: George, before we let you go, and you've been extremely generous with your time today. You've sold Molly on solar over canals. If I'm her secret Santa this year, I know what I'm going to get her, but I would like to come back to something you mentioned a little bit earlier, and that's the concept of a circular bioeconomy. I think most of our listeners are familiar with the idea of a circular economy, and I would say they're probably all very interested in the concept of a circular economy. But could you tell us a little bit more about a circular bioeconomy and how Water Xience is working to promote that?
George: Yes, so the circular bioeconomy is one where we look at bioeconomics, bioscience, bioengineering, and we really put the bio into that circle. In other words, we want to look at waste streams. We are kind of tied in agriculture and other things, and so we always want to look at waste streams and see how we can reuse them and be cleaner and more socially responsible, if you will. And so to give you an idea how that would work in what we're speaking about here, with respect to the solar over canal. So right now, the frames that support these panels are made out of steel. And you know, we're talking, U.S. steel, because we want to help the American economy. But when you look forward at how we can look at being circular, to give you an example, Bridgestone, which is a tire manufacturer here in America, they are now looking at what's called a guayule plant. A guayule plant is a plant that grows in the desert and it grows a bean, and so it's a low water user, it grows a bean. And this bean, you can extract and make rubber out of it. And so this is a bio-rubber. So now you have a natural rubber. And this natural rubber will be good. It may not last as long as another type of manufactured rubber. So what's going to happen is we're going to have a waste stream of this rubber. So we are approaching Bridgestone with the idea—I have the idea that we can take this rubber and we can blend it with Kevlar, and by doing that, you end up creating, with this waste stream, a structural member. So now I can take the waste from these tires, blend it with Kevlar, make a structural member and use that to support the panels over the canal. So now you see, I've created a biological circle, and so I've used that waste stream, and I've helped the whole thing economically, and everybody wins, including Mother Earth.
Dan: This has been such a cool conversation. Really, really appreciate your time today, hearing all about your projects and hearing all about what you've got coming up. I hope we can stay in touch. And I just like to say thank you, big, big, thank you for joining us on the podcast this week.
George: Absolutely, absolutely, you know, one last thing that comes to mind is when you ask me about why Gila River and why they're a good candidate, what's nice about that water district is that the system is brand new. So I have brand new canals, right? And so when you look at the economics, it's really favorable, because these canals are designed for a 50 year life, and now I'm going to put a structure over it that's going to last 50 years. So it kind of fits A plus B. The other part of it is, these solar projects are designed for a 25 year life. So once I build this frame over this canal, I'm actually going to get two life cycles of solar panels. And so when you're thinking down the road and the future and the next generation of solar panels, and how much they're going to produce versus the panels today, it's another reason why I think that, you know, Gila River’s so good, right? Because it's a new system. And so the economics in this day and age, that's the first thing everybody looks at, so the economics play out a lot better.
Dan: Well, Molly, I'm glad you were here today, because you were the perfect co host to talk about this project. Your article, super cool. We also have the other article that's in the show notes, about solar canals. This solution is a solution. It feels like something that is exactly the kind of thing we like to do, like my question to George about the benefits. We could have just done a podcast on that question because of the number of different kinds of benefits. Some of those benefits are easier to monetize than others, but they're benefits, and they're the kinds of things that will make these kinds of projects more enticing to more communities. One thing that I thought was really interesting was, you know, something we talk about a lot is the idea of replicability, like, what's being done in one place, can it be done in another? In this case, yes, it can. And George talked a little bit about the different sized pilots and projects that they're working on, but I really like the question about why the Gila River was the right place for this, and it really does seem like kind of a match made in heaven, the needs of the community, the needs of the environment and this technological solution that delivers so many benefits. So I think that was my key takeaway from today. I found that to be a really interesting part of the conversation.
Molly: Yeah, I really agree. It's just incredible to see the alignment with this community and this project that is basically tailor made for it. I really also liked when George was kind of describing all these co benefits in the way these canals work. I thought it was super interesting, because it's almost like it's its own ecosystem, where there's different factors, and you're ultimately creating solutions and co benefits, not just for one problem, but for several problems. And I think it's like you said, it really is a solution. And we could sit here and talk all day about how difficult and challenging it is to have water shortages and drought in the Colorado River Valley and out west. But what we really should be talking about is solutions like this that are community driven, and they're creating a lot of benefits. So I love it when we get to really highlight the name of our newsletter Climate Change Solutions. So like Dan said, you should definitely check out our article on the promise and potential of solar canals and get a deep dive into what these canals do and all the benefits they have. Otherwise, if you want to learn more about EESI’s work on renewable energy, head to our website at eesi.org and don't be afraid to follow us on social media @eesionline for all of our recent updates. The Climate Conversation is published as a supplement to our bi weekly newsletter Climate Change Solutions, which I'm always plugging. So check out eesi.org/signup to subscribe, and thanks so much for joining us and George, we had a great time, and we'll see you next time.
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