Speaker: Dr. Paul Bartley, Assistant Professor, Landscape Environmental Stewardship, Department of Horticulture, Auburn University
Moderator: Dr. Shimat Joseph, Turfgrass Entomologist, UGA
Duration: 55:54
Series: Green & Commercial
Webinar Date: March 12, 2026
Introduction
Shimat Joseph: Okay, welcome back. Let’s have our second speaker. So our second speaker is Dr. Paul Bartley. So Dr. Paul Bartley is an assistant professor of landscape environmental stewardship in the Department of Horticulture at Auburn University. His research and extension program focused on helping the horticulture and landscape industries navigate emerging environmental and regulatory challenges while maintaining functional and economically viable landscapes. His work examines sustainable landscape maintenance practices, outdoor power equipment technologies, and the role of policy in shaping landscape management. Dr. Bartley also leads collaborative research initiatives with industry partners through Auburn University Outdoor Power Equipment Consortium, working to evaluate technologies and strategies that support more sustainable landscape operations. Hey Paul, the floor is yours, okay?
Paul Bartley: Thanks, Shimat. Appreciate that introduction. Sure. Go ahead and share. All right, is that coming through okay? Yes. One second. Let me re-share a little bit. All right. Let’s ship it. All right. Is that okay? Perfect. Yeah. All right.
Do More with LESS — Framing Sustainability
Paul Bartley: Thanks again for the introduction. Normally I’m giving this talk to a room full of landscapers or golf superintendents, but often just a lot of normal people. So I’m not really sure where that distribution lies in today’s audience.
The today’s title is landscape equipment sustainability strategies. And so every presentation has to have a cute title. So this is do more with LESS. And what we’re really trying to do or capture here with our work is how can we promote sustainability? And that’s energy efficiency, that’s labor allocation, that’s cost, that’s emissions, noise, or — and so that’s kind of the primary focus on this. I do want to caveat all of this with I am completely pro-gas and pro-battery. We love all kinds of technology. What we really are seeking to do with this work is identify the best practices or where some of those gaps are in landscape maintenance.
One of the things that I learned early on in research was, you know, we don’t need any chicken little type of research. Or at least we need to do a good job of avoiding those hyperboles. And if you remember chicken little better than I did, because it took me a while to realize what he was saying. I you know he was famous for the quote the sky is falling the sky is falling right and a lot of times we use hyperbole like that in research to bring about justification or stress the importance of a work like this and I think this is a great example of this we often see graphs like this or information like it where these urban areas are rapidly expanding and in the state of Georgia the prime example is Atlanta and the urbanization around that metropolitan space. And the question that usually comes up or the fear that is being driven is how are we going to feed everybody? But I think what this trend actually amplifies is the importance of green spaces. And the question that we should be asking is how are we going to sustain everybody?
And so in that sustenance, you know, it’s more holistic than just food. It’s about our quality of life. And that brings into that conversation parks, gardens, and lawns, which the vast majority of people have. If you are in the landscape industry, or if you do have a lawn, I don’t really have to stress the importance of this. Really, what this slide should say is thank you. Thank you to all of those who assist in landscape maintenance practices. Thank you for creating beautiful spaces. Thank you for creating opportunities to get my kids away from screens and to have physical exercise and play. Thank you for the beauty that you bring to the world. There are so many advantages of a well-maintained landscape space in these urban environments that I think for the vast majority of people have gone unrecognized, you know, because most people don’t think about it. But I have the unique opportunity of spending a lot of time on a very beautiful campus and watching a lot of young people, you know, really achieve some of life’s greatest milestones, like graduating with their degrees, hopefully, and occasionally getting married and having receptions and ceremonies on campus. And I know that moments like this are really only captured because of moments like this. And there’s a lot of tremendous hardworking staff on campus that works tirelessly to maintain these spaces and provide those memorable opportunities for people to capture some of life’s greatest moments.
Industry Scale and Economic Impact
Paul Bartley: It’s a tremendous and huge staff that is responsible for maintaining this globally. And even in the Southeast, especially this is a giant. The green industry, which does encapsulate landscape architecture and ornamental production as well. But landscape maintenance in particular is the largest group within the green industry. It has a huge economic impact on the US. Just in the southeast alone, so that includes the states of Florida, Georgia, Alabama, Mississippi, South Carolina, I think. There’s about 235,000 landscapers employed, and nationwide over 100,000 businesses. Just in Alabama, it’s a $1.5 billion economic impact. And that economic impact usually tracks with population. And so if you weren’t aware, the metropolitan of Atlanta has a larger population in the state of Alabama. So that economic contribution in Georgia’s state is tremendous. But really the juggernaut in the southeast is Florida with their industry. It is phenomenal.
COVID-19 Impact and the Legislative Landscape
Paul Bartley: What happened during the last few years that’s driving some of these changes in perception, I think, in the public, which is resulting in different legislation, we’re going to kind of walk through this, is that COVID-19 impact. And I asked ChatGPT to give me an image that I thought best encapsulated what the average, let’s say, middle class employee went to, during that time and how this drove these changes in public perception about how landscapers are performing their tasks.
So if you look at the guy on the right, it was perfect. You know, it’s business up top, leisure down below, but he’s got no pants on, but still in those business socks. It’s hilarious. His son is shooting him with a Nerf gun. So he’s working under a high stress environment. Normally, he’s — kid would be at school learning and he would be in an office generally working. But that changed very drastically. And what that resulted in is a huge intersection with landscape maintenance practices under high stress environments. And what we see then is a dramatic increase in legislation that is trying to restrict what equipment is being used and how that equipment is being used. And that in different ways.
But at the same time, you know, we have several other trends coming about mostly in sustainable mindsets. So we got more gardeners, more people spending time outside, more people buying electric equipment during that time. And so the perception is battery is great. Gas landscape maintenance is terrible. And it’s driving me nuts. And the result of that was legislation.
California AB 1346 and Noise-Based Bans
Some of that legislation was trying to particularly carve the California Air Resources Board was trying to target emissions. And a lot of the equipment, at least the handheld equipment and leaf blowers or two-stroke engines, they’re dirty emissions. Okay. There’s no two ways around it, but that’s one of the catalysts. It wasn’t the primary catalyst. In fact, most of the legislation around the U.S. right now, which really was following in the footsteps of the California bill 1346, is citing noise. So most of it is about noise complaints, not about pollution. There’s just a couple of bands of restrictions. But you can see nationwide, particularly on the East Coast and then along the West Coast, a tremendous amount of legislation.
Georgia’s Preemption Bill
Now, Georgia curbed that legislation by passing what is known as a preemption bill. And so if you’re unaware, Georgia, in Georgia, smaller bodies of government are not allowed to pass more restrictive legislation than the state. And the state said you can’t ban landscape equipment. Therefore, no municipalities, cities or counties can pass more restrictive legislation. That’s a great thing. In the Deep South, we’re pretty much sheltered from a lot of this. But in pockets, it is showing up. And it might not show up in your area as a municipality or county or state ban on equipment, how you use it. But it can show up in communities still, in HOAs.
Equipment Transitions as Market Opportunities
And so the way we like to think about these things is it’s giving landscape maintenance operators the opportunity to change or appeal to different clientele, change their practices. And we love opportunities. We love opportunities. It’s just like organic food. No knocking organic food or traditional production. What I believe it does is it creates an opportunity for a producer to sell and promote his products to a different audience and market. So that’s why we’re kind of looking at this. I hope that you do the same.
Auburn Outdoor Power Equipment Consortium
Paul Bartley: How are we going to address this, though? What we did is formed the Auburn Outdoor Power Equipment Consortium. You know, how could we in academia help inform the industry on the differences in these different tools and technologies that are advancing at a rapid pace in the industry? We wanted to look at things like run time and energy consumption, force output. You know, how could we compare these tools apples to apples, gas against battery? to determine what these operational differences were. We’re also looking at things like cost and durability and industry perceptions with other partners. We’re looking at environmental impact as well, since some of the legislation is heavily focused on those concerns and the public is as well. But there are also other nuances to these tools like noise and vibration and safety that are a little more challenging to capture but could be very influential in differences between the technology. Autonomy is a big one for us too. There’s our autonomous mower and a big soft form. We do most of our testing, especially on the mowers and big sod farms. So that’s why we did what we did, why I created what we created and have some phenomenal partners contributing to that consortium.
Industry Survey — Equipment Purchasing Priorities
Paul Bartley: One thing we wanted to do that I’ll go over with you now is try to figure out what the industry’s perceptions were when it comes to landscape equipment. So we asked roughly 200 business owners, completed the survey and responded nationwide. And these were people that were self-employed up to 2,500 employees, maybe even more. Really large operations to one-truck operations, to rate their concerns when purchasing equipment.
And really, it was as expected. The equipment, in the eyes of the industry, must be reliable. It must complete the job. It must be available and easily maintained, because no one abuses equipment more than a landscaper. You’ll work them hard. And the least influential when y’all are making equipment purchasing decisions were things like power source and noise pollution, air pollution, and just really didn’t care at all. Very few instances where landscapers cared about any of those three bottom choices.
Principal Component Analysis
And really, those are operational efficiency factors. This is a principle component analysis. That is really confusing. This is a confusing graph. I’m going to simplify this. The things that are grouped together are the things that most landscapers responded to the questions similarly. So you care about air pollution and noise pollution and power source the same. You care about things on the right side, reliability, maintenance, customer service, availability, work capacity. Those are all treated the same. And things like ergonomics, safety features, and costs were really not that important. They were in between those things.
So those are kind of grouping those. I was kind of shocked about cost, but really what we took away from that, and it’s had confirmed, it doesn’t really matter how much it costs as long as the equipment performs as expected. So you get what you pay for. At least that’s what you’re looking at.
Company Size Analysis
We also tried to break this down. Okay, are smaller landscape operations more impacted by changes in legislation or battery powered versus gas powered equipment than big companies? You know, is that capital difference? Is that overhead difference a factor? And the cluster analysis that you see here told us no. And so again, don’t look at all the details. I’ll explain it to you right now. Landscapers are just normal people and we all have different personalities. And regardless of the size of our company, we’re all facing similar struggles and challenges. And we’re responding to those differently, just like we all have different personalities. So some of the largest landscapers and some of the smallest landscapers had the exact same concerns. But they just had the same personality. So there isn’t a particular demographic of landscape maintenance companies or operators that are affected by these challenges.
Battery Adoption Factors
Battery powered versus gas powered kind of equations. We asked the battery powered users to rate the factors that led to their adoption. Primarily it was noise pollution, but some of those same operational efficiency factors popped back up again. Things like reliability, work capacity, maintenance. Again, things at the very bottom were competitive advantage and cost. Competitive advantage was something I was hoping to see much higher on this list, but landscapers in general thought there was no advantage in to operating with gas-powered equipment over their competitors in terms of them offering that as a service. And it’s well-documented that the cost of battery-powered tools is significantly higher than gas, at least the capital cost. We’ll talk more about cost later in the presentation.
Then we asked the gas-powered users what discouraged them from adopting battery-powered equipment. Almost a perfect five out of five is work capacity. They also believed that they didn’t have the power, that the equipment was not manufactured with the same standards in terms of quality. I do think that some of these answers are probably some early adopter hangovers. Some of the early equipment had its struggles. I think most companies would admit that. I will say almost all the equipment that we have used has been exceptional. And we’ve tested a whole bunch. We then asked all those gas-powered users, that if their concerns with battery-powered equipment were addressed, so those things like work capacity, power, run time, stuff like that, if they were addressed, would they consider adopting battery-powered equipment? And the vast majority of people said yes, and what we want is superior technology to win, and I think the industry wants that as well. There was 15% that said no, and their comments were China, things like that. I can’t really do anything about where lithium ion is sourced, but it’s not just China. But you’re always going to have about 15% that don’t want to do it.
Runtime vs. Work Capacity — String Trimmers
Paul Bartley: All right, let’s talk about runtime and work capacity. What I want you to take away from this is that there is a difference. There is a difference in runtime and work capacity. Everybody I talk to says, “What’s the runtime?” I don’t think that’s the question you should be asking. And I hope this explains why.
I’ve got generic battery one, two, three through five, and three gas equivalents. These are string trimmers. And so if you look at the on these, we’ll go to setting two here, 45, 35, 36. Not bad, not too bad at all. If you look at high 55 even with some of these battery power tools. And so they meet or sometimes exceed some of their gas counterparts in terms of trigger time. So that’s full trigger presses and the run times are excellent.
Field Work Capacity Under Load
But if you look at field times, how much work are you going to be able to accomplish compared to their gas-powered equivalent? Those can be very different. And so we’ve got what we’re doing here is we’re simulating a work event. And we are string trimming around a chain link fence. It’s about a mile long. No one enjoys doing this test, but it’s very necessary. In the distance, look at the distance that you were able to cover on a tank or a battery with the gas power tools and battery power tools. So the run times were equivalent in the lab. But when we’re actually putting load on the tools, the gas power tools go in six to 7,000 feet, and the battery ones are trying to keep up. They’re doing their best, but sometimes a quarter of the output. And that’s a big factor. That’s a big factor.
String Guard and Line Effects
So not necessarily a runtime is most important, but it’s also how these tools are used or how they’re retrofitted. Most of the time, if you’re going to get a string trimmer and you’re a commercial landscaper, you’re going to pop that weed guard right off. So you’ve got a swath about 36 inches wide. You know, great efficiency, you know, is usually the thought behind it. There are also a lot of problems with removing that weed guard. One of those things is, especially if you’re operating with battery power tools, these tools are designed and engineered with motors and stream that is expected to perform within a certain range. And if you go outside of that range and the companies are not really happy with me for doing these tests, you’re going to potentially destroy your equipment. So I would encourage you to operate them as intended at all times. And that’s typically with the string guard on. And that string guard limits the line length. As you extend the line length, you’re going to decrease your runtime by about 30%. And also, if you change the diameter of the string, so if you go really thick line, you can decrease your run time by up to 20%. So line diameter is important. Twisted fine line is the best line. If you go anything other than twisted, you’re actually much, much louder. The line has a big influence on the aerodynamics off of that line. So fun work that’s being done there with string trimmers that we kind of didn’t really think about until we started comparing some of these tools.
Fuel Breakeven Analysis
Paul Bartley: If we look at some of these tools, the companies will tell you that the battery that you’re buying is your fuel up front. And we wanted to put that to the test. Exactly how much fuel would it take? How much run time on these tools would it take to pay for that battery with that tool? And it’s all over the board, right? So the yellow line here, and don’t worry about the colors of the line, they’re just to distinguish, it’s not identifying a particular brand. You know, it could be as much as 31 hours of runtime, it could be, or as little as 31 hours of runtime, or as much as 385 hours of runtime. And so that is a huge, huge spread. I’m just going to go ahead and say that not every tool is created equal and you will see big differences in ROI. If you’re going to talk about your return on investment, you’re buying your fuel up front with that kind of slogan, depending on the brand that you buy, depending on the brand. So, you know, do your homework well. I’m happy to tell you what’s a good deal or not a good deal, but I won’t tell you which brands to buy.
Backpack Blowers — Runtime, Output, and Recharge Cycles
Paul Bartley: Batpack blowers are a little bit worse than string trimmers. You know, minimum 255 hours, maximum 620 hours. But what’s different about these tools, again, these are lab tested trigger times. If you’re actually looking at at output. So these are the full trigger times. You know, we’re looking at on gas or better backpack leaf blowers. 89 minutes, 69, 25 on one, 100 on another. That’s a long time, an hour and a half. And our gas ones were roughly around an hour. You would be pretty impressed by those numbers. But again, it’s not how much runtime the tool has. It’s how much work the tool is putting out.
Force Plate Analysis
And so we do tests like these where we take a rubberized mulch. You know, it’s repeatable. We take a known weight. We distribute it along a test path, and we take multiple operators with different experience levels and we see how much time it takes for you to clear the debris off of the concrete slab. And so you looked at run times and you said, wow, these battery tools are keeping up or exceeding gas, but it actually will reduce your efficiency, you know, 2x, best case scenario, 1.4x. So you’re going to do much less work within a certain amount of time with these tools. And that’s really due to the output of the tools.
The battery powered, let me caveat this graph as well and what I’m about to say next. These are force plate analysis. So what we’re doing is we’re measuring the output of air out of the nozzle of these leaf blowers to determine, you know, does this meet up with what the marketing claims are of the tool? And gas-powered and battery-powered equipment is not matching the force that’s being advertised. In fact, some of the gas-powered leaf blowers were the worst offenders. Our handheld blowers are pretty equivalent to the battery-powered blowers in terms of the force that’s output, our backpack blowers are much less. And the truth is, it takes a tremendous amount of energy to force air, to collect air, compress air, and blow air. It takes a lot of energy. So these tools are working in overtime to try to accomplish this. And right now, the battery technology is really struggling to keep up.
Task Count Comparison
So the if we were to put this in terms of the amount of work that you could do with these individual tools compared to what’s traditionally used. So the gas number two blower is the most popular leaf blower on the market. You’re probably using it if you’re a commercial operator. The number of tasks in our simulation, not simulations, but in our protocols that you would be able to complete with the gas powered leaf blower is like 497 tasks. The leaf blower, the battery-powered leaf blower that had the best, let’s say, quote-unquote performance, would give you just shy of 300. The one that performed the task the fastest, you know, decreased efficiency by only 40% compared to… It’s only able to accomplish roughly 175 tasks. So the output on these tools is completely different. Even though the run times look great, the amount of work that you’re going to be able to accomplish is not comparable. It is not comparable.
It doesn’t mean that these tools are not useful. It means that under certain conditions where a tremendous amount of work is expected of these tools, some tools are adequate at meeting those expectations. And right now, most of the battery-powered tools are probably not capable of meeting those expectations. It doesn’t mean they’re not useful. It doesn’t mean that they can’t do the job. There’s just a change in expectations when you go from gas-powered leaf blowers to battery-powered leaf blowers.
Recharge Cycles and Battery Degradation
So I would really challenge you to think about these differently. This is back to the breakeven points on fuel. It’s not really about how much trigger time you’re going to get. It’s about how much work you’re going to output in these tools. And another important thing to consider is the recharge cycles on this. So this is the work output equivalent for a gas-powered to battery-powered leaf blower. Some of these are going to take over 5,000 recharges to do the equivalent amount of work per hour as the gas-powered leaf blower. And most batteries are sub-2,000 recharges. Recharge Cycles. You know, on your phones, your phones are a great example of this. When you get your phone, you’re using it all day and the battery life is still at like 75% at the end of the day. And you’re like, this is incredible. By year two, you know, you’re plugging it in at three o’clock in the afternoon. Batteries degrade over time and they degrade as we use them, as we deplete the energy within those cells and then recharge them. They recharge a little less every time. And so these recharge cycles are an important factor to consider. And at these recharge cycles, you’re going to be replacing batteries before you ever exceed the output of a gas-powered leaf blower.
So I point this out. This is the tool by far with the greatest distance between the output of the battery-powered tools versus the gas-powered tools debate. And unfortunately, most of the legislation is targeting gas-powered leaf blowers. And so I think it’s important that the public and that the industry understand these differences so that they can communicate those clearly with those expecting them to work differently. It doesn’t have to be a fight if we can just talk about these in terms of expectations and operational differences.
Decibel Dynamics
Paul Bartley: Leaf blowers again taking center stage in the noise debate. So let’s talk about decibel dynamics now. And really what I want to try to emphasize is noise isn’t loudness. Okay, so decibels are a measure of pressure, pressure and those waves of pressure or how we perceive sound. It functions differently than most people perceive. So, you know, an important thing to consider is that 85 dBA, which is our perceived pressure level over an 85 day. [VERIFY: “over an 85 day”] That’s when the National Institute for Occupational Safety and Health would consider that to be detrimental. But it’s a little bit more than that.
Real-World Decibel Measurements
So if we’re looking at the scale, these are things that I actually measured. My wife took out our three kids one day and I had the house by myself, no noise machines, no nothing. And she asked me how it was going. And I said, I think I hear worms digging outside. And so the ambient noise in my house was about 34 decibels. 34 decibels. If you’re having a whisper fight, if your child is sleeping or napping, that’s about 50 decibels. Mom on speakerphone is about 60. My five-month-old crying, I thought it was probably damaging, exceeding 85. It was actually in the high 70s. We shouldn’t say things like roll tide and go dogs. That’s very damaging to people, actually. And where we get into the landscape tools is typically above 90, and especially in leaf blowers above 100. So that’s in our leaf war zone in the fall time when all of our deciduous beautiful trees are dropping those leaves. If you enjoy football as much as I do, you know, stadium dBAs are definitely getting over 110. You know, that’s just to try to put some things in perspective.
Noise Is Contextual
But it’s not always about the dBA is what I want to emphasize. Noise is contextual. And it changes from person to person how you perceive that noise. It’s the combination of the environment you’re in and your tolerance of that noise. Some people love metal music. Some people love opera. Some people love country, right? Those that don’t love those other genres of music would consider some of that painful to listen to. And some people don’t enjoy the sound of a leaf blower as much as I do or the setting that most of the time leaf blowers are used in. So just kind of consider those things. It’s a very complex issue.
Noise Comparison Data
But actually, overall, yeah, the cumulative exposure of noise is greatest on mowers and trimmers than even leaf blowers. So let’s talk about these noise differences. Real quick, the output on a backpack blower like our Echo here is about 102 decibels to the operator at about three feet, 50 feet. So this is, you know, a bystander in the public space about 80. So pretty close to that 85 threshold. The operator on our Husqvarna backpack blower is about 82. So you don’t have to wear hearing protection. If you’re the operator, that is a phenomenal thing. That’s amazing. The comfort level of using these tools. For me to be able to teach tool safety to students and things like that, I have to teach with battery because I can instruct them while they’re using the equipment. At 50 feet, there’s a huge significance in the depletion of noise with battery compared to gas, and it’s 60. So it’s quite comfortable at that level.
The Logarithmic Scale
To put this in perspective, so dBA is measured on a log scale. So every change in 10, so from 60 to 70, is a doubling of the noise. So from 60 to 80, it’s four times the amount of noise produced by a gas-powered leaf blower than a battery-powered leaf blower at 50 feet. That’s significant.
We don’t see as big of an advantage in leaf blowers because it is extremely loud to spin a blade 18,000 RPM. Those hum, create a lot of noise. It’s slightly above the 85 threshold for the battery-powered mowers. But a significant reduction can be obtained.
Auburn Campus Case Study
Paul Bartley: And that’s really what we’re getting at. I want to go over this really quickly and focus on some of the more autonomous work that we’ve done, and to save time for questions. But we did do a case study on Auburn University’s campus. UGA did the same or something kind of similar. We have a beautiful campus maintained by Justin Sutton, who directs the landscape staff of about 85 people. This zone one here, we call that the face of campus. So that includes things like Sanford Lawn, the library, some of the ag buildings and things like that. This is amazing is where we’re at.
Battery Cost by Performance Tier
So we did some takeoffs on those. We understood how much is being maintained on about a weekly or biweekly basis. We tracked fuel consumption, time allocation. And what we did is we took that amount of energy, either that fuel in milliliters. I’m sorry, I went to milliliters. I promise there’s a reason we did that per unit maintained and whether or not, that stacked up really well with our lab test. And so what we were able to do was to say, okay, if this is what’s being used for the gas-powered tools, here is the battery-powered equivalent within three brands. And I’m going to call these brands high-performance, mid-performance, and low-performance, okay? And that’s somewhat of a judgment. I don’t mean to be judgmental about these. I love all the equipment. But some of them just perform differently. So we’ll just say the output was differently with these tools.
And the cost factor. So the number of batteries that you would need for each tool to maintain that space each time that it was serviced. And so this is capital cost, roughly 45 grand. We go to our medium performance. We see a slight increase in the number of batteries that we’re going to need in order to maintain that space. The cost goes up just barely about 46 grand. These batteries are actually cheaper per unit than the high performance. The low performance is the most budget friendly per unit. But in order to complete the maintaining that space, we need a significant number of batteries, 60 something batteries. And the cost was about the same then. So the cost of acquisition was roughly the same. And the cost of acquisition does everything to factor in the cost of ownership and the return on investment on these tools.
Return on Investment
So if we were to compare brand new gas powered equipment and these three battery brands to maintain this space, you would finally get an ROI after about eight years. And this is no deals, no package deals, no incentives, no tax, because we were tax exempt on campus. So we’re not shopping deals. You know, everything is an independent unit that’s being purchased. So it’s not a string trimmer with five batteries, not a string trimmer and a blower, that kind of stuff.
But this graph is really important to explain a couple of things. One is if you do an equipment ban, you’re going to have a lot of equipment. You’re not starting the gas-powered graph at $18,000. You’re starting it at zero. And so that’s going to significantly change your ROI for any landscaper that’s forced to purchase all new gas-powered equipment in order to provide services to the community. That’s not good. We’re very against bans. We’re definitely for incentives if that’s the direction that the legislation is going. But we prefer no legislation at all. Again, the best tool will win. And the technology being integrated into these tools is improving rapidly.
But also, I’d like to point out, when you reach that ROI, you’re going to be a good tool. Look at how much money you’re saving very quickly. And so when you reach that tool, that ROI is the most important factor. So get the best equipment available for you that you want at the cheapest price, because the lower that cost of capital is, the lower that cost of capital is. The faster you’re going to get that ROI, the faster you’re going to see the potential benefit of battery-powered equipment. It’s critical, critically important.
Autonomous Mowers — Efficiency and Energy
Paul Bartley: All right, now I want to take some stuff that’s more or less hot off the press and really all we do is cut grass. There’s a lot in autonomy right now. We’re trying to. We’ve done a lot of a significant amount of work. We’ve mowed about 300 acres this summer, collecting data on every acre. You know it. This is really the backbone. This tool is anyway of landscape maintenance practices. It’s about 70% of the cost of landscape maintenance in terms of energy consumption and labor time. And typically, you know, it’s your high skilled employee is operating this tool.
These autonomous tools are designed to function pretty much without an operator as soon as there’s some manual inputs provided. We’re not talking about the, I call them robo mowers down at the bottom. These are commercial mowers that can function autonomously. So they can operate manually just as your typical commercial mower, 60-inch deck. But then, you know, you can open up an app in your phone and select a work plan and tell it to, you know, maintain that space as long as an operator is, let’s say, babysitting it. Okay?
Partners and Testing Protocol
And the apps are cool. These are great. The only reason that I’m able to share some of this work with you is some — the phenomenal support that we’ve gotten from Greenzie there in Atlanta, who retrofits some of the equipment that you’ll see. And Doosan Bobcat, who has allowed us to work on the prototype. Some of the claims, though, that we were investigating or potential benefits were things like less time, reallocation of labor, precise mowing patterns, things like that, increased efficiency and higher fuel efficiency. And some of the limitations that we were aware of are sensor reliability, you know, landscapes can be complex. Obstacle detection, safety of these things is a huge factor and cost we know is very important when considering adoption in the industry. So we took those two research objectives to evaluate the energy demands and efficiency and ROI for these tools. And we also looked at safety.
So let’s talk about the efficiency on this. This is kind of our overview of our protocol here. We looked at two different landscape designs. One, plot one is just a square acre that our mower is going to maintain. And plot two there has some tree rings, which you see the autonomous mower going around, and then a really large T in the bottom. And we realized we made a huge mistake when we did the study that we are now advertising for the University of Tennessee. So we should have done a big AU in it, my mistake. But we’re evaluating how much energy is consumed in maintaining those two plots between gas-powered, gas-powered manual, gas-powered autonomous, battery-powered manual, battery-powered autonomous. All trying to figure out this efficiency and ROI factor. That’s really important. Again, with the largest, most expensive tool, most time consuming tool, most energy intensive tool and landscape maintenance.
Industry Partners
But here they are. The only reason I’m sharing these names now is that they’ve allowed us to do so. And I think that speaks volumes to these companies and the services and products that they’re providing, they perform great. And these are great people, great companies. I have nothing but praise for them. There are differences in the tools. And I also want to caveat that from the beginning of our testing of autonomous mowers to the end, there was a tremendous amount of improvement that we saw. In fact, I was begging them to stop improving the mowers because it was changing the data that we got while we were collecting it over the summer. So, you know, the data that you see here now may not be what you experience in the field. So please understand it’s just a comparison here to really, I think, to encourage conversation about how these tools operate.
Energy and Time Comparison
Energy consumption, you know, if we look at it in watt hours, which is not typical language, but we can compare gas or transform gas units to watt hours of energy. Look, our battery powered tools are a more refined source of energy. So it’s not really a fair comparison. The reason why I showed you it in milliliters is if we compare watt hours to milliliters of fuel, it’s actually really similar.
One of the biggest questions that we get asked is, “Well, how many batteries do I get?” It’s as simple as this. If you track the amount of fuel that you consume, you don’t even have to do it by tool. Mowers are going to consume about 75% of your energy. Blowers about 20% and handhelds five to 10, somewhere in there. If you can track those, it’s almost a one-to-one comparison of fuel that you can use to watt-hours of energy that you would need to maintain it. It’s almost a one-to-one comparison. So that’s what we’re looking at here. It’s not as hard of a conversion as you might think.
Energy consumption for all autonomous gas-powered mowers is much higher than all of our manual mowers. Our manual mowers, you know, the guys operating these are extremely efficient. The autonomous mowers are not as efficient. And they take much longer. So the time to cut is much greater. The autonomous tools just take much slower to turn. They overlap more. They operate at a slower speed. Those are all settings that can be tweaked to more efficiently maintain those. Those are things that were improving as we were testing them. Those were important considerations.
Autonomous Mower Cost and the Dual-Mower Strategy
Paul Bartley: We calculated the lifetime cost estimates for these tools. That’s what I’m going to share with you right now.
All right. So our ROI on the battery-powered mowers, the energy cost per acre is pennies. It barely keeps up with inflation, the operational costs on the electric equipment. But the lifetime cost, because the tool is much more expensive, that increased capital costs, is roughly equivalent to the gas powered mowers. So over the lifespan of the tool, you’re going to spend roughly the same amount of money for a manually operated mower, whether it’s battery or gas. How they figured that out when they were pricing these tools, I don’t know. I don’t believe that they were doing these calculations. But that’s what our data showed. Very similar results. Eventually, over time, yes, you are going to recuperate that increased capital cost to buy a battery-powered mower.
Now, comparing the manual mowers to the autonomous mowers, quite a bit different. So a huge increase in capital costs, 15,000 compared to 45,000. The lifecycle cost, if you look at that, there’s no manual operator included in that lifecycle cost. So it’s much lower. But look at the production of the autonomous tool compared to the manual. It’s almost half. And so over the lifetime of that tool, we’re assuming about 3000 hours, 500 hours per year, so six years. It’s actually cheaper per acre for a manual power mower than an autonomous mower. But that’s not the only way that you can potentially use these.
You know, the dual mower strategy is having one guy on a mower while supervising an autonomous mower. You can be 55% more efficient with that. Your labor costs will go down about 40% with that strategy. So there are different ways to implement these technologies than just an apples to apples comparison. That’s kind of what we were hoping these numbers would reflect. There’s different ways to use these. There’s different applications. There’s settings where they’re more efficient, settings where they’re less efficient. But what is true is they’re rapidly improving.
Safety Testing — Obstacle Detection
Paul Bartley: This is our safety protocol. So we’re putting obstacles in front of these mowers. And when people approach me with safety concerns about our autonomous mowers, like you don’t complain when you see a Tesla driving autonomously down the road at 70 miles an hour. Why are you complaining about the autonomous mower traveling three miles an hour? You know, it’s, there are things and settings that we’re comfortable with these things and there are also things that we’re not comfortable with these things.
Let me tell you, after running over a lot of baby mannequins, I’m concerned. Okay. But our tools, our tests were designed to expose weaknesses. Okay, so we’re putting them in extreme situations that they should not be in to try to expose some of these weaknesses.
Detection Rates and the Speed Trade-Off
Okay, overall, this is a radar based system and a camera based system. Our detection probability is about 93% with our camera based system and much lower with our prototype. It’s a prototype radar based system. Again, these are things that are going to rapidly improve. But as we talked about the technology improving, as you increase the efficiency of these autonomous mowers, what you see is this ring expanding and contracting. And that’s its range of detection for these obstacles. And so the faster it moves, the faster that ring is, or the larger that ring is, of detection. But when you do that, you start increasing things like shaking and bouncing and the ability to identify an object then actually degrades. The slower the mower moves, the smaller that ring is. And so things like turns, very quick turns into the mowers, stuff like that, that’s where we’re potentially seeing a lot of problems running over small objects and objects lying down as well.
And what is a kid gonna do? You saw that little squirrel that was actually my kid’s Halloween costume. You know, just like a squirrel, my kid, second after being released from our house, ran out into the road. That’s what kids are gonna do. They’re going to run straight into hazards. And so it’s really important. You know, I think we’re one tragedy away from some of this technology being set back to use these tools safely. Okay. Do not operate them outside of their intended use. Follow the instructions and guidelines of the companies to a T. That is the most important thing. Safety is the most important thing. Okay.
Data to Decisions
Paul Bartley: From data to decisions, let’s just go overall. Know your equipment usage. If you want to make wise decisions, right? and what tools you use and what’s best for your companies and clientele, you have to understand how you’re using them currently. And so the more data you have, the more equipped you are to make those decisions.
You need to understand energy equivalent requirements. I’m happy to help you understand that. We’ve tested about five or six different brands. Very gracious to all of those who have participated.
Capital Cost is the most critical factor. Get the best tool you can at the cheapest price. But that is not without saying. Beware of unforeseen costs with cheaper batteries. You’re generally going to get what you pay for. Good friend of mine operates with Makita batteries. Very happy with all the Makita equipment that we’ve tested. He bought some that were cheap from a reliable source. And they ended up being fake batteries and caught on fire. And, you know, that was a big problem. So be aware of that. Be skeptical. You should be. You also need to be aware of the capacity of those batteries. You know, I said charging infrastructure for 65 batteries. Are you going to be able to safely deploy those in the field in a trailer in order to complete your work? You know, you need to be very conscientious about those decisions. Not every cheap battery is a good battery, and get the best deal for your infrastructure capacity.
Acknowledgments
We’ve kind of gone over that. All of this work has been a lot of fun. I love cutting grass. I love testing blowers and thinking about how we can answer some of these questions for the industry. But really, it’s all been an excuse to work with great people. And a special shout out to our collaborators within OPEC, the graduate students that have participated, the companies that have allowed us to do this work and associations, as well as the support that we’ve received through the USDA, AMS, and some of the companies that have participated in this. So there’s just a few minutes left. I really appreciate y’all’s time. And I’m happy to answer any questions you have except for what brand should you buy. Not going to do it.
Questions and Answers
Shimat Joseph: Thank you so much, Paul. It was an excellent talk. Let’s wait for a few minutes again to see whether there’s any questions there. We have about six minutes left to five. So, you know, please ask any question you may have on this topic that Dr. Bartley kind of went over.
Paul Bartley: Yeah, I’m happy to hear what tools you’re using, if you love them, if it’s autonomous, battery, gas, if you’ve got any inputs to share. I love that.
Shimat Joseph: Any questions?
Autonomous Mowers and Pollinators
Shimat Joseph: So let me ask you this question since we’re waiting for her. So Paul, when you tested all these automated systems, have you looked at coordinators? Because I was interested in coordinators and there’s a lot of bees, activities in the long run. So is those things, you know, you showed another image of, I want to say, a model there and that you went over kind of thing. So is there any observations or any thoughts about that?
Paul Bartley: What a mower’s impact would be on pollinators? Because I think one of the questions was, if you have one of these robo mowers, which are extremely quiet, you know, they’re sub 50 decibel outputs, they’re extremely quiet. Would the bees not be able to know that they’re coming? You know, is it going to surprise the cacom [VERIFY: “surprise the cacom”] and we’re starting to, you know, going to reduce our pollinators, especially with a lot of research on alternative lawns? I think it’s taken off a lot of places. I believe some preliminary work was conducted in my conversations about that. If I’m remembering right, there were no differences. But I would not be surprised if someone saw more or less pollinators in a gas-powered mowing scenario versus these autonomous robots. That’s come up a couple of times. Appreciate you asking.
Hedge Trimmers
Shimat Joseph: Do you have any questions, too, Paul? It’s like our audience is very silent today.
Paul Bartley: Yeah, they’re here to hardworking people cashing in their CEUs.
Shimat Joseph: Yeah, I see one question here. Have you done any work with hedge trimmers?
Paul Bartley: Oh yeah, we’ve tested all the hedge trimmers. There are differences across brands. There are a handful of brands that produce hedge trimmers that are the Rolls Royce of landscape equipment. I mean, it is the most phenomenal battery power tool of the whole lineup. They are whisper quiet. They are extremely efficient. That is the one tool that far exceeds the efficiency of their gas powered equivalent. That’s the first one that I recommend landscapers try. Because I haven’t met one yet that’s been disappointed. They’re a little bit heavier. You do have some increased fatigue with that. But battery-powered hedge trimmers are a 10 out of 10. And again, there are some differences across brands, but find one, test one out. What I tell everyone is if a company will not allow you to try a tool, try some of theirs, trial them out, don’t buy it. I think that’s really important for your employees to get their hands on it, to get an opinion. I’ve also seen opinions change huge from week one of using the equipment to month three. You know, it’s night and day. They all of a sudden love this about it that they didn’t realize and they’ve had a lot of fun with it.
Chainsaws and Additional Tool Recommendations
Shimat Joseph: And there is one comment, maybe you can read that.
Paul Bartley: Chainsaws. Chainsaws are great. Very good. I’ve tested some, three or four of them, different brands. They were great again. That’s actually chainsaw produced the loudest decibels of all landscape equipment. So the battery powered ones are amazing comparatively. Chainsaws are great. Hedge trimmers are great. String trimmers are often used a lot. We recommend battery powered blowers for what we call janitorial blowing. You know, clearing off sidewalks, curbs, things like that. You’re going to notice a big difference in gas and leaf and battery powered blowers when it comes to heavy leaf drop season and wet leaves.
We do test a few of those. We’re collecting data on them now. We spent last year operating with some of them. I can’t tell you that they’re going to be more efficient. The efficiency of a commercial lawn mower is really high. We haven’t looked at ROI yet. That’ll be this year. I will say this. My kids love them. Kids in my neighborhood love my robotic mower. We’ve got them deployed at arboretums. You know, I think there are settings that are amazing for those tools. And the business models are kind of being worked out around them and how much you need to service them. Because the one in the arboretum, I have to go visit every two or three days because someone’s picked it up, and they have to be manually reset when that happens. So those tools, autonomous mowers are great, but they do. It’s an absolute necessary to evaluate the property first and remove any obstacles or hazards that might reduce the efficiency of that tool or create problems down the road.
Closing
Shimat Joseph: Thank you so much, Paul. Thank you so much for your talk and we all enjoyed it. And I am pretty sure we all learned a lot. Okay.
Paul Bartley: Thank you. Great questions. Thanks, everyone, for participating. Thanks, Shimat, for the opportunity and all those others with this webinar.
Shimat Joseph: Sure. So this basically concludes our webinar for today. And if you, Richie, if you have any thoughts about the CEUs and things like that.
Rich Braman: Sure do. I sure do. Let me just pull this up real quick. And Paul, that was really interesting.
Paul Bartley: I’m glad you enjoyed it. Like I said, usually all of us at some point have a mower, blower, string trimmer in our hands. So maybe we can all take away something from that.
Rich Braman: Very much so. I was going to say, some of those emails you get might just be from me.
Paul Bartley: I’m happy they’ll. [VERIFY: sentence cut off at recording end]
Transcript processed for UGA Center for Urban Agriculture / GTBOP Archives
Source: Corrected SRT (Stage 1) — GTBOP_Transcript_2026-03-12_LandscapeEquipment.srt (948 blocks)