Emission-free and totally automated are the key words that set the range of ETMowers from Etesia apart from anything else on the market.

Protecting our environment has us all looking for alternatives to petrol- powered mowers that produce outrageous amounts of emissions and other nasty pollutants. Current rechargeable mowers use extremely heavy lead acid batteries and can weigh as much as some users.

The new Lithium powered range of ETMowers is here to change the landscape. Etesia UK has recently installed one of its robot mowers to maintain a large area adjacent to their base in Oxfordshire in a rather testing environment. The aim? Apart from being able to show potential customers the mower in action, the company also wants to demonstrate the positive impact little and often mowing can have upon the turf itself.

There are three models to choose from which and are finished in the company’s colours and, most importantly, sold and supported via Etesia’s UK dealer network. As to the range, the entry level Etesia ETm44 is designed to operate on areas of up to 5,000m2. Height of cut can be set in nine positions between 22mm-75mm.

Next up is the ETm65. This is designed to mow areas of up 9000 m², height of cut from eight cutting positions covering 22mm-65mm. This larger model weighs in at 36kg and is capable of working on a slope of up to 30%.

Suitable for areas of up to 20,000 m², the ETm105 is able to mow golf practice ranges, football and rugby stadia, practice pitches and other large areas. Eleven cutting positions give a height of cut range of between 22mm-80mm. This model weighs just 51kg.

The mowing elements comprise a three-bladed cutting head powered by a direct drive, brushless motor. Mounted on parallel arms to allow contour following, the motors spin the cutting discs at 3,500 to deliver a high blade tip speed.

Offering cut widths of 44, 65 and 105cm, the ETm44, ETm65 and ETm105 have two, three and five cutting heads respectively. The reversible blades, which are similar in size to a traditional razor blade, are designed to last around a season before they need to be turned. And when it comes to replacement, each blade will cost around 70p.

In fact Etesia suggest an annual service will cost as low as £150 for the ETm105. There is not much to go wrong on these mowers, periodic cleaning with compressed air typically being all that is needed to keep the units going between services.

How does it work?

The mowers are programmed to mow in a random fashion, their boundaries being set by a buried wire in the ground. If your robot needs to recharge its batteries, it automatically goes back to its docking station and resumes mowing once it is fully charged. As the units are pretty much silent in operation they can be left to run day or night with no need for any operator input.

The area to be mown is mapped out by the boundary wire, the latter having a charge that is picked up be a sensor on the mower that essentially prevents it crossing a fixed line. In addition, the mower has a pair of radar sensors to enable it to steer around a goal post, tree, bench or similar, a front lip mounted pressure sensor also stopping the unit should it bump into something.

Another sensor detects if the unit is flipped over, stopping the cutting units and also alerting the user via a text message that there is something wrong. Speed sensors will also detect if the unit is moved quickly, such as may be the case if someone tries to steal the mower. A GPS system will then alert the user to its whereabouts, the systems shutting down to prevent the mower working outside its boundaries until it has been re-set by entering a password.

They mow, you don’t!

It follows that there will be periods when grass growth will not keep up with the full-time mowing regime offered by the ETm mowers. To prevent non-productive passes, the mowers will detect if they are not actually cutting anything, sensors that detecting the load on the cutting discs. No load on the discs suggests no grass is being trimmed.

What separates this simple load sensing apart, however, is that the mower will still stay out, moving to other areas to see if there is grass to trim elsewhere. This enables the mower to tackle areas where grass growth may be patchy. It also follows that the software controlling the mowing pattern needs time to ‘learn’ how to control the mower.

On a separate point, the mower will always return to the docking point via a different route. This is to overcome the possibility of creating a track each time it comes in for a charge.

Who will buy one?

As with existing robot mowing systems, demand will ultimately be drawn from large domestic and commercial users. But Etesia is keen to initially promote the mowers use in applications to include stadium maintenance mowing. Because the mowers are designed to be in full time operation, the controlled environment of a stadium will enable customers to get the best from the mowing system. The key is that by keeping grass trim without tying up an operator, the mowers will have a fast pay back in this type of application.

In Europe, around 200 mowers have been sold for this type of work, with users preparing and mowing pitches in the traditional way for match days; the mowers cover the area at random to reduce trafficking, so cannot leave TV friendly stripes on the turf.

To suggest the mowers can only work in a fixed and easily confined area, however, is countered by Etesia setting up its own large demonstration area. This includes areas within which there are unguarded trees and obstacles, with a decidedly irregular boundary too. The aim is to show the potential to mow public spaces to include parks and gardens.

How much do they cost?

Etesia divides the cost of setting up a robot mowing system into three:

Mower cost. These are from £4,196 to £10,451

Charge docking station. A single station is £799, but more than one may be required for complex layouts

Cabling. Installed and buried using a purpose designed cable layer, the cable itself costs £270 per 300m drum

Taking a stadium football pitch as a costing example, installing an Etesia ETm105 based system will coast around £12,000. Following installation, the mower will maintenance mow the pitch with no operator input, so it is just the cost of powering the unit that will needed to be added.

On the continent, users suggest an ETm105 based system installed for stadium mowing will have a pay back period of 2 years; this takes into account labour and conventional mower fuel costs.

Etesia (UK) has specified more expensive Lithium, as opposed to Nickel Cadmium, batteries for all ETm mowers sold in the UK. This is largely down to its experience will Pellenc battery powered equipment, the longevity of Lithium power having proven to save on overall operating costs.

This should mean an ETm105 working in a stadium will be active pretty much 24/7, only needing to be stopped when the pitch is to be mown for presentation for a match and during post match pitch cleaning; the mowers have a deflector which will push aside divots etc. but the mower has no means to collect debris.

Etesia ETm105 – outline specification

Cutting system: 5 discs with 3 blades

Height of cut: From 22 to 80mm

Cutting disc motor: 3 phase, 24 volt, 50 watt

Disc speed: 3,500 RPM

Back wheel motor: 24 volt, 50 watt

Rated area capacity: Up to 20,000m2

Guide capacity per hour: 3,600m2/hr

Weight: 51kg

Length: 130cm

Height: 50cm

Width: 120cm

Recharging Station: 30 volt AC

Peripheral Wire: 0.5 volt, 50mA

Transformer: 230/15 volt, double insulated

Consumption: 100 watts/hour

For further information, please contact Etesia UK on 01295 680120 or visit www.etesia.co.uk