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Community and Q&A

Small Engine Equipment

AugieMarsh | Posted in Green Products and Materials on

When replacing a gas lawn mower with an electric model, does it make more environmental sense to destroy and recycle the working gas unit or sell it and allow it to complete its useful life (lets say 10 seasons of moderate use). Intuitively, it seems that continued use would quickly make less sense than destroying it, but maybe I’m missing something.

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  1. Expert Member
    BILL WICHERS | | #1

    I am nearly always opposed to destroying an otherwise functional unit. My recommendation is to keep the gasoline fueled unit until it's no longer serviceable (typically when maintenance costs exceed the replacement cost of the unit). If you want to replace it now, I'd sell it through one of the used equipment channels (Craig's list, Ebay, garage sales, etc.) so that someone else can use the remainder of the useful life of the machine, then put the money you make towards the purchase of the new unit.

    New electric mowers are not without their own impact enviornmentally. I have my doubts actually if the entire manufacturing impact for the electrical lawn equipment is really worth it overall compared to the impact of a fuel-powered unit. With an existing fuel-powered unit, I hightly doubt an electric unit will be less overall impact than continuing to use the existing machine that has already been manufactured. If you only compare emissions from fuel, you'll miss the big picture of the manufacturing impact (which is worse for the electric unit), and the fact that charging the electric unit in many cases will also have some associated emissions, although likely much lower than what you get out of the small engine as exhaust.

    Nothing works out perfectly, unfortunately.


  2. Tim_O | | #2

    Small engines are some of the most harmful environmentally, as they do not have catalytic converters. CO2 is of course just a function of fuel used, but the other harmful emissions in a little Briggs engine will far exceed that of a car (with functioning catalyst).

    With that said - if it works, it's not great to destroy. Just put it at the curb, I'm sure there is someone who could use it.

  3. AugieMarsh | | #3

    Thanks for the feedback. I will see to selling the equipment. Bill, overall non-combusting lawn equipment (and all equipment) would have to be the answer to severing ties with fossil fuels in a lasting way....or do you see a hybrid blend creating this necessary reduction?

    1. Expert Member
      DCcontrarian | | #4

      If we're able to stop dumping carbon into the atmosphere, this is how I think it will go:

      Burning fossil fuels on an individual level -- heating, transportation, cooking, lawn equipment and the like -- will stop. That will all go electric. At the same time, we just don't have the capacity in renewables to stop burning fossil fuels completely. It will be limited to large plants where we can control and capture the emissions. The carbon that is captured will be sequestered, or used as feedstock for plastics and synthetic hydrocarbons for applications where electric is never going to have the energy density --aviation, for example. Since these hydrocarbons will use captured carbon they will be net-zero-carbon.

      By powering everything off of the electric grid our energy usage will be more flexible and adaptable. Switching to a different fuel becomes a matter of retrofitting a few power plants rather than retooling the entire economy.

      The changeover to all-electric will take years if not decades, and mostly will happen through regular attrition and replacement. The rumors of jack-booted thugs coming to tear out your gas stove are unfounded. Right now electric devices are being subsidized, but I could see a switch instead to personal use of fossil fuel getting expensive to encourage people to replace older equipment.

      So the short answer is that gas mower will probably die from throwing a rod before it becomes impossible to get fuel for it.

    2. Expert Member
      BILL WICHERS | | #6

      A hybrid won't really do anything to help with a lawnmower. Hybrids help in cars because cars run at varying speeds, which means varying loads on the engine, and cars stop and sit idle at times too. Hybrids increase fuel efficiency by capturing some of the energy during braking that would otherwise be entirely lost as heat, by making the engine run at more constant loads during driving, and by letting the engine shut off altogether instead of idling.

      Lawn equipment tends to run the small engine at or near full load for near the entire time the machine is operating. There isn't any lost energy that a hybrid system could recover in this case.

      What I think will happen is electric machines will get used by people with smaller urban/suburban lots, where there are some other advantages to electric equipment (quieter, no need to keep fuel on hand, etc.), but people with larger lots can't really use them because battery powered equipment is currently too underpowered. I can mow my several acres worth of grass with my riding mower, for example, but there aren't any suitable electric replacements for it. The same goes for chainsaws -- the electric ones just don't have the power (but probably will at some point in the future). I personally would love a decent electric chainsaw to replace my gas ones, since the chainsaws are incredibly noisy for their size. Electric chainsaws are apparently less safe though, since safety equipment like chainsaw chaps have a harder time stalling the chain on electric driven saws (I have tried very hard to avoid testing this though! :-)

      I think going after small engines is more trouble than it's worth in the grand scheme of things, and the manufacture of the electric equipment IS more resource intensive than the manufacturer of the combustion engines. It's not just about steel, it's about all the other materials that go into the things, and dealing with them when they eventually die. It's pretty easy to recycle a combustion engine, for example, but not so easy to reprocess a large rechargeable battery pack. There are always tradeoffs.

      My basic view is that a large scale transition is much further off in the future than people would like to accept. I have no problem working to get there, but it bothers me that people are often interested in artificially accelerating the timeline and ignoring the realities of the hardships this can impose. A good example is the desire to transition to all electric vehicles, but that just isn't possible in the timeframes people propose, based on a combination of manufacturing capacity, resource availability, and electric generation. There is _NO_WAY_ that a transition to all electric for current electric generation, new load from replacing combustion heating devices, and new load from replacing combustion engines is going to run on wind and solar alone. There are certain practical realities here that need to be dealt with, and they're often ignored, which is a problem.


      1. Expert Member
        DCcontrarian | | #9

        I think we should be focusing on electrifying interstates and major highways rather than extending battery ranges. It just seems crazy to have every car carry around a couple thousand pounds of batteries for its entire life just so that it can occasionally be driven all day and 99% of the time it doesn't need that much capacity.

        1. Expert Member
          BILL WICHERS | | #13

          But that leaves all the back roads. If you want an all-electric car, it's all or nothing for electrification if you don't have a battery. A hybrid arrangement might work, something like what the Chevy Volt had, but with electrified major roadways. This way you get power from the grid on the interstate, and switch to battery for the smaller roads. I'm not sure how a roadway could be electrified in a practical and safe way though -- multilane roadways are much more complex in terms of where the traffic can go compared to something like a railway with a very predictable (and thus, easy to wire) pathway.

          It's all these other issues that make me really doubt we are going to be able to electrify a majority of vehicles in the arbitrary timelines that are usually proposed in regulations. Even aside from the generation and capacity issues, there are so many other things that come into play to complicate things.


          1. Expert Member
            DCcontrarian | | #15

            I'm thinking a battery with a 40-50 mile range, how much of the US isn't within 40 miles of a multilane highway?

      2. Expert Member
        Michael Maines | | #18

        I grew up mowing 2+ acres with a 1970 GE Elek-Trac lawn tractor. The tractors are still around and kind of a cult item; a friend of mine runs a store supplying parts and reconditioned machines:

        I've been using chainsaws since I was about 9-10 (don't tell CPS) and I absolutely love my Makita 36V chain saw. It's not as powerful as my Stihls but I've cut down many decent-sized trees with it. One charge on the batteries conveniently lasts about as long as my back holds out, and I have a whole suite of Makita cordless tools so I can always swap out batteries when needed.

        This whole debate reminds me of something that happens on virtually every design project I've ever done: I draw what they want, a contractor prices it, it costs more than they want to spend so they try to find something expensive to cut out that won't affect their lifestyle at all. There is never such a silver bullet; the only way to get the price down is to balance "needs" and "wants," looking at every item and making hard decisions. Every decision matters, and we aren't going to get where we need to be if every time we look at something polluting we say that its impact isn't enough to matter.

        1. Expert Member
          BILL WICHERS | | #19

          I basically agree, it's just not realistic to think that the new electric machines can replace the fueled machines right now, and probably not in the near future. For many on smaller lots, the electric machines are probably fine, and have some advantages (lots quieter, lower maintenance). Where I have an issue is some of the efforts to require people to use the electric machines in areas where the electric machines really don't make sense yet. Replacing perfectly workable fueled machines is really a different issue, and I think it's best to either use those until they would be getting replaced anyway, or sell them to others to use, rather than scrapping them immediately and replacing them.

          It's not just about money, it's practicality too, and the overall impact when considering scrapping and replacing currently workable machines. I wouldn't get overly focused on any one of those issues, I think it's best to try to consider the entierty of things and try to get to the best option in each case rather than overly emphasising any one aspect of either type of machine or issue.


  4. Expert Member
    Michael Maines | | #5

    Small engines are terribly polluting, with more than four times the carbon emissions of burning gas in a car, plus other emissions that are bad for health due to the lack of a catalytic converter. I've seen it compared this way: running a lawn mower for an hour is like driving a typical car 300 miles. There are embodied carbon (aka up-front) carbon emissions in the machine but steel emissions are around 1.5 pounds of carbon for every pound of steel, so scrapping/recycling the machine is likely to be a net positive for the environment since lawnmowers are pretty small and light.

    That said, not everyone wants or can use an electric mower, and the emissions from one machine probably aren't worth worrying too much about on the grand scheme of things. But emissions add up, so if and when a large percentage of the population switches to electric, it will make a difference.

    1. Expert Member
      BILL WICHERS | | #7

      I don't see how you can get any more carbon emissions from a small engine compared to a "large" engine in a car. You have the same carbon content per unit of fuel going into either engine, so the same amount of carbon that can be released in exhaust, regardless of what the engine is doing to burn that fuel. The entire issue with small engines is the "other stuff" that comes out, which is certainly a problem, and anyone's nose can detect that it's happening! Small engine exhaust is way stinkier than automotomile engine exhaust, and it's a combination of the fuel injection system constantly adjusting the fuel/air mix for the engine based on operating conditions and the catalytic converter that deals with a lot of the other stuff.

      I personally much prefer the quiet and smooth operation of the electric machines, but need the energy density provided by combustion engines. I'm quite certain that at some point electric machines will "catch up", but I think it's a least some years off in the future before that will happen. For now, I grab my hearing protection when I go to run the riding mower. I do have come concerns that people overlook the additional complexity of reprocessing the batteries especially from electric machines compared to the relatively easy to reprocess metal content from a combustion engine too. That's something I think really needs to be considered to avoid switching the problem from engine emissions to hazardous solid waste generation. There needs to be a process to deal with the electric machines, especially their batteries, when they reach the ends of their lives.


      1. Expert Member
        DCcontrarian | | #8

        I'd say the chainsaw is a good use case for something that's going to be hard to electrify. You need good energy density, and they're often used for hours at a time. I was using a chainsaw the other day and a thought occurred to me: how much would gas have to cost to make it not worth my while to use a chainsaw? (IE use a hand saw instead) $50 a gallon? More? I mean with a pint of gas and a chainsaw you can cut a lot of wood!

        Applications like that will be the last to electrify. I also think we'll start synthesizing net-zero-carbon fuels pretty soon, I understand aviation fuel is just about at the point where it's cost-competitive with fossil fuels.

        1. Expert Member
          MALCOLM TAYLOR | | #10


          Many of the tree services around here have switched to electric chainsaws when climbing and limbing. I can't see them for falling or bucking though.

          1. Expert Member
            DCcontrarian | | #12

            Are there battery-operated chainsaws with a chain over 16"? I haven't seen one. That would limit the usefulness.

          2. Expert Member
            MALCOLM TAYLOR | | #14


            No, I think the Husky has a 14" bar, which is probably optimized for a saw with that power.

            Last summer I helped clear brush from several acres of land around a lighthouse near us. I brought my small saw, and the two other guys had Milwaukee electric ones. They had a much better day of it. I was torn between letting mine run constantly while gathering piles, or shutting it off all the time and having to pull it. If my small one dies, I'm definitely going to replace it with a battery one. I can keep it in my truck to deal with downed trees on the road too.

          3. Expert Member
            BILL WICHERS | | #17

            The smaller electric chainsaws are handy for some things too. I have an electric pole pruner that works pretty well, but it's a small 8" chain if I remember correctly. The battery goes at the end of the pole near the handle, which helps to balance the saw. The gasoline fueled versions put everything at the end of the pole and are actually more difficult to handle.

            I find a cordless sawzall with a good pruning blade (I usually use the Diablo one, but there are others out there) is great for pruning smaller branches. I often reach for the sawzall over the chainsaw even for larger branches if I have only one or two to deal with, simply because the sawzall is easier to deal with -- but it does cut much more slowly for larger branches.


        2. Expert Member
          Michael Maines | | #20

          My cordless Makita has a 16" bar: I realize that you said "over 16"" and even 16" is somewhat limiting, but works for the vast majority of non-professional tree cutters.

        3. Expert Member
          PETER Engle | | #38

          I think a chainsaw is an excellent use case, in favor of electric. As most people with woodlots do, I currently own three saws: a tiny battery powered Stihl limb saw with about a 5" bar, a 14" Ego battery saw, and a 20" Stihl Farm Boss gas saw. My woodlot has primarily trees less than 50 years old. If a big one needs to come down or get cut up, I get out the Farm Boss. For just about everything else, I use the electrics. With 2 batteries for the Ego, I rarely run out of battery power before I run out of personal energy, and it's got the guts to cut at full saw depth for quite a while. It uses a relatively skinny chain and it is important to keep it super sharp. But the benefits of no noise, no smoke, no idling, etc. far outweigh the downsides.
          Except in winter. For some reason, the Ego batteries totally suck in winter. For winter work, it's the Farm Boss all the way. Still, I'd say I can do 2/3 of my work with electric, and that's with current technology. As batteris and motors get better, we'll see more and more market penetration. There are already battery powered riding mowers that outperform gas in every way, including range. The transition is here, but we're just at the beginning. Rather than being disappointed or doubtful, I'm astonished at the speed of the transition to date, the rate of technology improvement, and even the rate of recognition of electric benefits and adoption by people who wouldn't seem to be the types.

    2. Tim_O | | #16

      While it's correct that small engines are significantly dirtier than car engines due to the lack of catalysts and non-ideal combustion, carbon is where they are efficient. Running an engine at WOT is its most efficient. This is actually why diesels are a few percent more efficient than gas engines, no throttle blade in a diesel!

      CO2 is a direct resultant of the amount of fuel used. Basically, every gallon of gas you use is ~20lbs of CO2 no matter if it's in a car, truck, or lawn mower.

  5. ohioandy | | #11

    Not mentioned yet is the absurdity of the lawnmower in the pantheon of modern carbon squander. In modern America this machine and the work it produces has become integral to the social fabric and seems beyond reproach. The endless seas of mowed lawns and ditches, the mindless repetition. For what? Gas or electric, it seems an alarming waste.
    On a practical level, given that all the machine is doing is chopping blades of grass, I wonder if any other motor, combustion or electric, expends so much energy to accomplish so little. Is it possible that most of the energy of the engine is given to overcoming friction in the engine and wind resistance of the blade? But I've also labored with an old push reel mower in the past; those things are truly exhausting!
    Chainsaws are a little harder to dismiss... their work seems marginally more defensible.

    1. Expert Member
      MALCOLM TAYLOR | | #22


      "Chainsaws are a little harder to dismiss... their work seems marginally more defensible."

      For some of us in rural areas, indispensable.

  6. DennisWood | | #21

    Bill, I have one of the inexpensive corded pole/ 10" saw combinations that works surprisingly well for our needs with 20 odd trees on our urban lot. I've used that same saw to buck up 18" maple tree trunks left over from a removal last year. Not ideal, but for our needs that saw is 100% awesome and keeps me off the ladder doing seasonal trim/clean up. No carbs, no batteries. I had a few gas chainsaws and sold them all. Gas/ignition/carburettors = too much wasted shop time, at least in my book.

    If you're cutting several acres, then I would ask the question, why? Going to a landscape that does not include grass (at least the domesticated variety) means you have more time for other things, no? I just use a Fiskars (person powered) reel mower 95% of the time which is a pretty relaxing, surprisingly efficient, way to cut grass :-) We're on a 150 foot lot which is shaded by about 20 mature trees. Zero water, zero fertiliser. If things are out of control (or for fall leaf mulching), I have an electric mower and 200 feet of cord. We had a landscape architect draw up some landscaping plans for our site, and in the end, there will be even less grass. It will be replaced with low ground cover, shrubs etc.

    The only thing left in my gas powered collection is a snow blower which cannot be replaced yet with an electric variant as I keep our driveway clear, and a back lane which a growing number of seniors need for access. I honestly don't enjoy working on carburettors, recoil mechanisms, or any of the other things that regularly go awry with gas powered things..including cars. The ICE cars in our driveway hardly move, whereas the EV is managing 95% of our family transport needs. Not a cool EV btw, just a boring 2018 LEAF SL we bought for 23K CAD a few years ag0. As a guy who a hoist in his shop, doing my own mechanical work for 35 years or so (including engine conversions) I love, love, love the mechanical simplicity of the EV.

    1. Expert Member
      DCcontrarian | | #23

      "I honestly don't enjoy working on carburettors, recoil mechanisms, or any of the other things that regularly go awry with gas powered things..including cars. "

      Amen brother.

      Although I was thinking the other day that like many men my age I have an immense store of knowledge about how to get internal combustion engines to start by fiddling with chokes, throttles, spark plugs, glow plugs, starting fluid, etc. That vast store of knowledge is rapidly becoming obsolete.

      With electric it's either charged or it isn't.

      1. Expert Member
        Michael Maines | | #24

        My small engine and chainsaw repair person is a woman. Just sayin'. But I know what you mean.

    2. Expert Member
      BILL WICHERS | | #30

      I live on just shy of 24 acres. There is maybe 2 acres of grassy area, the rest is either woods or a small lake. I have zero intention of ever trying to make the woods into grassland -- I love the woods, that's a big reason why I bought this lot :-) What happens though is that there is always deadwood and storm damage coming down, often from the edge of the woods into the grassy areas. On average, I have about one good size (foot or so diameter) tree come down into the grassy area every year. I have had such trees come down during storms and block my driveway before, which I have to clear. The entire community (it's a "semi-rural" area) tends to cooperatively clear fallen trees and branches from the roads after these storms too -- it's not just road crews, utility crews, and fire department (which are volunteer here) crews doing the work.

      Chainsaws are pretty much a requirement to live on heavily wooded land not because you want to clear the land, but because you have to deal with fallen trees and branches after nearly every strong storm that blows through. I've never taken out any tree here except for invasive autumn olives (which are a thorny weed of a tree), but I've had to chop up many fallen trees, some dead from ash borer damage, or one of the pine borers, others just came down in storms.

      I think it's common for people in more urban areas to think chainsaws are used to take down trees, but in wooded areas they are actually much more commonly use to clear trees that come down naturally that would otherwise block roads, or harm other healthy trees (think "big tree falls into smaller tree"). I've cut fallen tree parts out of healthy trees before too, to allow the healthy tree to continue to grow without getting damaged.


      1. Expert Member
        Michael Maines | | #32

        Bill, my situation is surprisingly similar--I live on about 26 acres, 2 acres cleared, with lake frontage and a farm pond. I am working on clearing trails to get around the woods but for every standing tree I cut, I probably have to clear two storm-damaged trees. I just walked down to the lake a couple of weeks ago and once the snow is gone I have about a dozen trees to clear from the trails.

  7. Tim_O | | #25

    One of my thoughts on electric lawn mowers - the robot mowers have really come a long way. And unlike a manually operated mower, it doesn't necessarily matter if it needs to come back to the home base to charge once or even a few times to finish a cut. I also never want to have huge fields of grass to mow. I've always envied the lawns in Arizona, plant a few rocks and a cactus. Trim it once every century and be done with it.

    1. Expert Member
      DCcontrarian | | #26

      If you had a robot mower, it could be a lot smaller and move a lot slower. If you need to mow one acre once a week, that's about four square feet a minute over the entire week. You could have a mower about 2" wide that moved at walking pace and did that - even if it spent two thirds of the time charging. Imagine a little robot the size of a mouse that spends 24/7 out on the lawn, mowing for a bit then coming inside to charge.

      1. Tim_O | | #34

        They have gotten better, but my robot vacuum hits the same spot 10 times before getting the dog hair in the corner.

    2. nickdefabrizio | | #36

      I thought about this alternative, but the set up and limited range (one acre) made me go with a used Greenworks electric riding mower for my 3+ acres of lawn... I am hoping that they will develop an affordable AI self driving module that can be wired into an electric riding mower (they already have them for golf course sized mowers, but they are still too expensive for me)

  8. plumb_bob | | #27

    If you are worried about environmental impact, look to replace your lawn with something more friendly to the birds and the bees. There are non-lawn yard ideas that will increase biodiversity and reduce water and other inputs. Seems the gas vs elec motor argument is downstream of this basic decision.

    +1 on loving electric chainsaws for shop work or light duty cutting, buy I will be keeping my gas saw for remote or heavy cutting.

    1. Expert Member
      DCcontrarian | | #28

      I really think it's different on the east coast. Any land that isn't mowed at least twice a year gets overgrown with briars and poison ivy and becomes extremely unwelcoming to humans. Anything over six inches tall is prime tick and mosquito habitat. If you have outdoor space that you want to enjoy, mowing is the low-cost, low-effort maintenance. There's a reason highway medians are mowed and not xeriscaped.

      I don't water grass, and the only input is mowing.

      1. Expert Member
        BILL WICHERS | | #29

        DC, you forgot kudzu. I remember driving around the beltway some years back in the Northwestern part, and thinking "look how green the sides of the roads are". Then I realized it was nearly all kudzu in the trees, lightposts, everywhere. That stuff grows like crazy!


        1. Expert Member
          DCcontrarian | | #31

          This is the land of vines. If you don't mow around your house the vines will rip the siding off your house in short order.

  9. plumb_bob | | #33

    Hmmm the ticks, poison ivy, briars and invasives don't sound fun. I will stick with our grizzly bears and black fly swarms.

  10. nickdefabrizio | | #35

    I love buying equipment used. My 60" Exmark gas zero turn lasted 10 years after I bought it from a landscaper who thought it was almost done...Now I just replaced it with the 60" Greenworks electric (see below) I got used for less than half price. I have over 3 acres of grass to mow and the electric can do close to 12, so it should be fine. It is much more powerful and fast than the Exmark. I will charge it at night when the grid gets less stress and I have PV panels so the excess energy I use will allow me to increase the number of panels to offset the usage. Also, I no longer have to drive to the gas station to fill up 5 gallon gerry cans. Of course, it would be better to just let the grass grow, but that is a bridge too far for my wife at this point, so the electric mower is a compromise.

  11. mikesmcp | | #37

    Just Too Many People.

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