Going Green
Over the last few years we have been increasing our number of cordless commercial battery powered machines as and when they become available and viable to purchase. This process started with the purchase of a cordless blower, chainsaw, strimmer and pole pruner from the Stihl range in the summer of 2016, and these have proved so successful that they have now been added to with an additional blower, a hedge trimmer and two Kombi power units which can be used with strimmer, edger and hedge trimmer attachments.
The advantages of these machines are not only reduced carbon and other pollutant emissions, but also hugely decreased noise levels (and who hasn’t become very annoyed at screaming two stroke petrol leaf blowers everywhere in the autumn?), they tend to be lighter to use than their petrol equivalents and completely remove all the toxic fumes from the operator and the local environment.
The machines also have significantly decreased maintenance costs and the frequent problems of getting two stroke machines to start are a thing of the past. The publicised advantage of reduced hand arm vibrations however does not seem to be borne out of the figures provided by the manufacturers so I’m not sure where that idea has come from, however the figures are still well within reasonable levels.
All these machines can run off the same batteries, either a heavy duty backpack one that gives run times of in excess of three hours (depending upon the machine used and how hard it is having to work, or smaller removable batteries that either clip into the machine itself or connect to it via a hip belt or shoulder holster. The batteries all charge off a standard 13 amp socket via a fast charger and take from 30 minutes to 3 hours (for the backpack) to charge depending upon how depleted they are, thus only costing a few pence to charge.
Some comparisons:
| Model | Stihl cordless blower | Stihl petrol blower |
|---|---|---|
| Weight | 2.5kg plus battery (1.7kg) on belt | 4.4kg |
| Sound level | 75 dB(A) | 104 dB(A) |
| Power – air throughput | 1040 m3/h | 800 m3/h |
| Vibration | 2.5 m/s2 | 1.9 m/s2 |
Now thanks to a generous donation from the will of Anthony James Earl, some careful budgeting and the sale of outdated machines and following on from the success of these handheld machines, we have now been able to add some bigger, battery powered pedestrian controlled and ride on machines to our fleet.
The first to arrive was a Mean Green CRX 60” zero turn ride on lawn mower, this is an American machine designed and built by an ex aircraft engineer, which has three of the latest lithium batteries which give it a run time in excess of seven hours following an overnight charge.
Again this is much quieter than its diesel engined predecessor, the electric motors making almost no noise, but the three cutting blades still make it noisy enough for the operator to need ear protection, however the noise level to bystanders is vastly reduced.
Maintenance is minimal, consisting of keeping the machine clean and the batteries, controllers and fans free of grass. The only wearing parts should be the cutting blades that will need replacing annually at a cost of around £150. This compares to the previous machine that needed an annual service in excess of £700, plus frequent belt replacement and periodic changing of blades as necessary.
| Mean Green CRX Mower | John Deere 1565 Mower | |
|---|---|---|
| Sound Level | 68 dB(A) | 90+ dB(A) |
| Vibration | 2.22 m/s2 | 0.5 m/s2 |
Second to arrive was another American product, a John Deere TE Gator utility vehicle used for moving people, equipment and resources around our site, this is powered by eight traditional lead acid batteries, so needs a tiny bit more maintenance to ensure the batteries are kept clean and topped up, but again an overnight charge is more than enough for a full days use.
We have found a snag with this machine, in that as it’s so quiet, nobody hears its approach and despite a flashing orange warning light many visitors to the Meadow are getting quite a surprise!
This electric Gator doesn’t have the carrying and towing capacity (roughly half) of the existing diesel powered machine, but it’s more than adequate for the lighter duties and frees up the older machine for the harder working of moving heavy mowers and other equipment around the site.
The last to arrive and the latest to the market (ours was only the second machine delivered in the UK) is an Allett C34 Evolution cylinder mower made in Britain. This uses four removable batteries (that can be used in other machines) which give a run time of around four hours, so it’s worth bringing some back to charge up at lunchtime so that a full day’s work can be completed. Again this machine is eerily quiet with only the whirr of the blades, making it ideal for working in the quads around the college.
These three machines all charge off a standard 13amp socket making additional specialist charging points unnecessary and costing only pence at a time to charge.
Unfortunately these machines come at a high price and if it wasn’t for the generous donation we would not have been able to buy all three at once, but the vastly reduced fuel and servicing costs should bring the lifetime costs of the machines down to a reasonable level. Certainly knowing that the machines are not going to be a battle to start, tend to be lighter to use, don’t deafen the operator and those near them and don’t go along in a haze of pollutants make them all a pleasure to use.
Of course, having zero emission machines is really only an environmental benefit if the electricity used to charge them is from a renewable or carbon free source, and to that end the House Surveyor has commissioned a feasibility study to install a PV solar charging system on the roof surfaces of our yard buildings facing away from the Meadow and into the sun, so let’s hope that comes back with a positive result and then we’ll be able to say that our machines are truly green.
As technology improves and more products become available we can look forward to a future for horticultural machinery that is not only carbon and other pollutant free but is also much quieter, and hopefully it won’t be too long before we can get smaller cylinder mowers, rotary mowers and the other more specialised equipment in battery powered form.
