Time for mowing and gardening contractors to go electric. ?

Forums › Off topic › Time for mowing and gardening contractors to go electric. ?

ezbee

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#295443 29-Mar-2022 17:08

Honestly I have been kinda wondering about this for some time.

After reading a bit here on Geekzone re discussion on electric lawnmower brands.
( Though the conclusion was more that providing lawn was not to big etc. )

When will they get to the point where they are powerful and rugged enough to be used day in day out by mowing contractors.

Then this popped up.
Why a lawn mowing company is ditching petrol power for battery power
https://www.stuff.co.nz/national/300547642/why-a-lawn-mowing-company-is-ditching-petrol-power-for-battery-power

Though I am a bit dubious on the size of solar panel being enough to keep things charged,
So maybe you have a bunch of pre-charged packs to last the day ?

If an electric van has an appropriate high current supply, that may be useful for charging,
depending on the distance of average lawn mowing round. IF you go electric top to tail.

It could catch on in city more for the quieter operation too.

Jase2985

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#2893622 29-Mar-2022 17:37

Looks like they are charging a DC battery and then AC charging the mower/tool batteries. There is a 2000w inverter in there. a couple of 200-250w solar panels on the top of the trailer and you would be able to keep up with things

when you do the math on the charger to recharge a 56v 5ah battery it takes 280w of power and 40m of time, and will charge a 7.5ah battery in 60 mins (420w). it would draw about 2A at 240v.

This gives you about 45 mins of runtime.

I have 2 x 4ah batteries and 1x 2.5ah battery and i can do all my edging 1 pass vertical edger then 1 pass with the line trimmer, then mow, then use the blower without needing to stop. that's on about 200sqm of lawn.

It does seem dooable but i suspect they will be going through batteries every couple of years, and at $600 for a 7.5ah battery that's a lot of fuel.

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ezbee

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#2894099 30-Mar-2022 09:54

Jase2985

Thanks for the info on panels I had underestimated the power capability of these.
I guess you get a bonus on some days and others oh well.
Some places don't get that much sun most of winter.

Battery replacement cost and life is going to be key by look of it.
Maybe if repacking batteries can be an economic reliable option.
If vendor does not lock the battery management system to prevent this.
They will quickly be racking up charge/discharge cycles.

Suppose much depends on the ruggedness of electric mowers they can find, can they save on maintenance.
Gas mowers have to be built with a certain heft and strength just from point of view of vibration of the IC motor.

Temptation with electric may be to downscale everything forgetting that a mower still gets a thrashing from grass cutting and material picked up by blades.
Being pushed over uneven ground edging, weight of catcher if used.
Otherwise electric motor should be very maintenance free, its all the other bits.

Suppose they might get an advantage with certain clients favoring the low noise,
and maybe the odd council contracts to bank some CO2 reduction targets.

Indeed that may be the hook, commercial contracts where customers can claim some Co2 reduction ?

insane

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#2894118 30-Mar-2022 10:44

I don't think reliability would come into it. They would surely use Honda, Toro, Stilhl etc, not the stuff you typically find at Mitre10.

If we're reached the tipping point then great! Many tradies have been running full battery for a while now for their tools now that 56/60v tools exist.

Scott3

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#2894123 30-Mar-2022 10:53

This isn't a new thing.

Other companies have been doing this for year's.

1st class Gardens sign writing their e-nv200 back in July 2018 turned up an a quick search.

No photo description available.

They have photos of Ego gear too.

I seem to recall another brand posting pictures of their e-nv200 setup too. Can't for the life of me find them. Setup with ego too. They had a cambervan style house battery setup in the van. Lead acid battery bank and solar panel on roof. I assume they charged all their ego-batteries, van & house battery overnight, and then between the house battery & solar pannel there is enough power to recharge any batteries that go flat during the day.

Now and then I see people maintaining Auckland council facilities running battery gear too. often Stihl brand, with a backpack battery:

https://www.stihl.co.nz/STIHL-Products/STIHL-Battery-Electric-Power-Systems/PRO-Battery-Electric-System-for-large-gardens-and-professionals/PRO-Battery-Electric-Batteries-and-Chargers/261316-1621/AR-3000-Backpack-Battery.aspx

Geektastic

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#2894192 30-Mar-2022 12:43

I have a zero turn John Deere Z540M. It has a 52” deck and a powered bagger.

The engine is a 25hp Kawasaki V twin.

On a full tank I’d expect at least between two and three hours mowing. A contractor would need to be sure of double that per day I would think.

The other issue is weight and turf care. The larger John Deere mowers such as you see councils using are quite heavy but fine for that sort of mowing. Ornamental lawns would show damage quickly with heavy machines.

Batteries big enough to mow 6 hours might be too heavy I suspect.

spearsniper

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#2894227 30-Mar-2022 13:27

I suspect mowing contractors are a way off going all electric.
To mow my lawn which takes 2 hours with a 23hp mower, you'd need approximately a 30kWh battery. In context, this is the same size as used in a Nissan Leaf. It weights about 750kg, which in itself is an issue - more power required to move all that weight, and ruts in the lawn.

A contractor would go broke if they only mowed 2 hours a day, so the capacity required in a battery would need to be triple that.

The little handyman outfits that can use push mowers might be a different story tho.

mudguard

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#2894260 30-Mar-2022 14:17

I think there is quite the large leap between domestic and commercial use. I just bought that 18V Ryobi Brushless lawn mower. It's comically small and light, but it matches my comically small lawn. But it bogs and cuts off quite easily. There's now way I'd use it for anything larger. That said, I am using it ultimately to mow/scarify about four inches of thatch so have it lower than one should for just a regular mow.

But I have been impressed with it.

Reminds of that Harry's Garage video with the boss of JBL. He spoke of electric being great for passenger cars, things that might have 100-200 hours of use per year. But his big machines were in the thousands of hours per year.
My mowing takes about twenty minutes and then it's done for a week. Lawn after lawn after all day would need a lot of juice.

Scott3

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#2894316 30-Mar-2022 16:25

The early adopters in regards to the shift to electric commercial outdoor power equipment (OPE), will be the somewhat less demanding commercial applications. Think maintaining inner city urban lots. The likes of mowing sports fields, is likely to be combustion powered for some time yet.

Notice that many of these operates are using the likes of the e-go brand of OPE. Well regarded stuff, but largely consumer targeted.

That said, solid commercial focused offerings coming to the market. As an example the Stihl AR 3000L backpack style battery (1520Wh, RRP $2445 for the battery alone).

And the Mower range here. Sweet spec's suiting a commercial operator and a price tag to match (i.e $23k for the NZR-48 / 52 Nemesis). No price iss listed for their flagship, but it comes with either a 22kWh or 35kWh battery, and advertises 4.5 hr and 8 hr run times respectively annd comparable power to a 37hp diesel. 767 to 840kg.

http://meangreenmowers.co.nz/

As a general note the OPE market has become a heap more crowed over the decade of so. Historically it was largely the domain of specialist brands like Stihl, Husqvarna etc.

But with the advent of high powered battery power tools, pritty much every power tool brand has seen the opportunity to jump into that market too. Dewalt, Makita, Ryobi, Stanly fatmax etc. Many of those brands have higher voltage (than the 18V typical on power tools) battery systems or run dual 18V batteries, to get sufficient power for intensive tasks.

And of course new brands like e-go have sprung up to capitalistic on the transition.

So there is a mountain of products and completion in this space.

And it's only going to get better in terms of electric offerings. California is banning the sale small off road engines (spark ignition under 25hp) from 1 Jan 2024. This is due to the fairly nasty emissions profile of small engines. So every new chainsaw, leafblower, small lawnmower etc sold their will need to be electric.

spearsniper:

I suspect mowing contractors are a way off going all electric.
To mow my lawn which takes 2 hours with a 23hp mower, you'd need approximately a 30kWh battery. In context, this is the same size as used in a Nissan Leaf. It weights about 750kg, which in itself is an issue - more power required to move all that weight, and ruts in the lawn.

A contractor would go broke if they only mowed 2 hours a day, so the capacity required in a battery would need to be triple that.

The little handyman outfits that can use push mowers might be a different story tho.

Your numbers seem wide of the mark. Don't have the 30kWh leaf pack weight on hand, but the 24kWh pack weighs 225kg, and the 40kWh weighs 303kg.

https://www.marklines.com/en/report_all/rep1786_201811

Also not that just because your lawnmower has a 23hp engine (17kW), doesn't mean that that it is close to using all this power, all the time. Perhaps the engine is at max output and bogging down, if you are mowing a thick tuft of grass on a steep incline, but most of the time it will just be making a fraction of the rated power. As a proxy you could look at fuel use. 1 liter of petrol is 8.9kWh, if the engine was 25% efficient, and running flat out the entire time, you would expect to burn about 15L in 2 hours. Suspect actual use is heaps lower.

PolicyGuy

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#2894337 30-Mar-2022 16:56

Scott3: As a proxy you could look at fuel use. 1 liter of petrol is 8.9kWh, if the engine was 25% efficient, and running flat out the entire time, you would expect to burn about 15L in 2 hours. Suspect actual use is heaps lower.

At that rate (15L in 2 hours), it would be costing you over $40 just for petrol to mow your lawns, and probably over $50 by next Spring if Vlad the Invader continues the current unpleasantness in Ukraine.
Seems like a pretty damn good argument for an electric mower!

1101

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#2894549 31-Mar-2022 09:09

Actual use petrol isnt that high , for me.

With a 5hp petrol mower , at FULL POWER for 1/2 the lawn , on my overgrown lawn , not even one tank of gas on the mower .
So, beggar all petrol actually used. Most home lawns contarcters see will be much easier to mow , and less to mow .

So I dont know where some claimed petrol costs come from, seems too high ?

Geektastic

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#2894555 31-Mar-2022 09:17

I can say that the the normal way to run a mower such as mine is that the engine is at full throttle all the time the blades are running. That’s what the manufacturers recommend.

mudguard

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#2894580 31-Mar-2022 10:22

Geektastic: I can say that the the normal way to run a mower such as mine is that the engine is at full throttle all the time the blades are running. That’s what the manufacturers recommend.

I suspect most of that horsepower is being used to move the mower rather than going all into the blades.

Scott3

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#2894585 31-Mar-2022 10:41

For clarity, pretty much all petrol lawnmowers engines will be fitted with governors.

As such pushing the engine speed control lever to the fast position (indeed the recommended way to operate), doesn't mean the engine will be running at full power.

Typically the governor will be automatically throttling the engine down to keep the engine at around 3600RPM. It's only when one attempts to mow through especially thick grass, and the RPM starts to drop, that the governor will fully open the throttle, and call for full power.

Also when in engine is bogged down, peak power drops. In the below example if really thick grass caused the engine speed to drop from 3600 RPM to 2300 RPM, peak power drops from 12kW to 9kW.

Small Engine Suppliers - Briggs & Stratton 16 HP VANGUARD Model Series 303400

Net result of all the above is that the engine will be running at fraction of it's rated power for most of a lawn mowing session. (doesn't take much energy to spin the blades in air). Largish engines than are strictly needed are just desirable and popular to avoid bogging down (and associated change in appearance of mowed grass), in thicker section's, abnormal mows like when the grass has got super long over a holiday etc.

As one would expect when the engine isn't working very hard, it consumes less fuel. My fuel burn calculation was intended to illustrate that the engines aren't working very hard. And as such, actual fuel burn will be heaps less than if the engine was running flat out.

And it follows that an electric mower can get away with less battery than would be calculated based on a mower running at full power.

Scott3

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#2894593 31-Mar-2022 11:05

PolicyGuy:

Scott3: As a proxy you could look at fuel use. 1 liter of petrol is 8.9kWh, if the engine was 25% efficient, and running flat out the entire time, you would expect to burn about 15L in 2 hours. Suspect actual use is heaps lower.

At that rate (15L in 2 hours), it would be costing you over $40 just for petrol to mow your lawns, and probably over $50 by next Spring if Vlad the Invader continues the current unpleasantness in Ukraine.
Seems like a pretty damn good argument for an electric mower!

Actual fuel consumption will be a lot lower. Perhaps half the theoretical max?

If it was half (might be less still), that's 7.5L / mow. Say 40 mows a year (fortnightly in at time when grass grows slower). = 300L / year. $900 a year at $3/L

Ruining a quick comparison between this $7799 petrol mower:

https://worldlawn.nz/product/worldlawn-viper-xl-50-kawasaki-fr691v-23hp/

And this $26450 electric mower (6.72kWh, approx two hectares / 2.5 hr range):

http://meangreenmowers.co.nz/the-nxr-4852-nemesis/

Gives a 21 year payback time (assuming free power giving a $900 per year operational cost saving).

Probably getting up towards the useful life of the mower, and likely too long to justify on a cost basis for most home owners.

So would need to be justified on another basis (say lower noise, or environmental).

Of course for somebody with twice as much grass, the numbers would look a bit better. Approx 10.5 year payback... But would need to split the grass into two batches with a 3 hr charge in between.