Solar powered Lawn Mower

Anyone got one? lol

I was thinking with the price of fossil fuels going sky high it was time that we got together on a little project of making one of these little electric lawnmowers that runs on 12 Volts...

Is there anything out there that can be chaged up in the garden hut on a solar panel to cut the grass?

I could cut my grass with the petrol lawnmower when grass is too heavy and wet,But the idea of keeping the grass down with an electric lawnmower powered by 12-24volts battery...IS LOOKING MORE NEEDED!!!! :idea:

[Gotwind Ben]

A great application for solar Vic, I had thought about it a while ago.
Maybe we need to go back to the old push mowers for ultimate energy saving (and exercise).
Most mowers are used maybe once or twice a week, the rest of the time the can be (hopefully) solar charging.
And as summertime gets the most sun, when grass is growing, it's ideal.

A nice Instructable here.
http://www.instructables.com/id/solar-lawn-mower/

and of course a hugely expensive commercial version £2.5k ($3.5k)
http://www.autobotics.co.uk/shoponline/ ... ybrid.html

and
http://greatgreengadgets.com/gadgets/20 ... pollution/

I have given serious thought to a "robotic lawnmower" similar to the HV Ben linked to. With GPS modules < $50 and many other easy options for relative positioning with very close tolerance, there really isn't any reason a DIYer could not design and build a very reliable robotic lawnmower. Charging it via solar/wind would involve the usual trivial but expensive components. Power consumption could be from 500W to 1.5kW depending on width of cut and travel speed. Assuming "continuous cutting" of a lawn during the course of a week, a 250W PV panel might allow as much as 7 to 21 hours per week of "cutting" during the Summer months.

Charging the unit via the grid would allow considerably larger areas to be maintained. Using 2.8Ah LiOn batteries 20 to a string (74V) would take roughly 2.4 strings per hour of operation @ 500W, or 7 strings per hour of operation @ 1.5kW. For 8 hours of continuous operation 20 strings (400 batteries) @ 500W to 60 strings (1200 batteries) @ 1.5kW. At $7/battery, this represents $2800 to $8400 in batteries alone, but this does not preclude it being a worthwhile investment.

Assuming the mower could maintain ~1 Acre per hour of operation, the device would be capable of mowing > 50 Acres per week. 50 Acres represents roughly 75 homes in a medium size residential neighborhood. If the average homeowner in such a neighborhood spends or pays $25 per week for lawn maintenance this amounts to $1875/week. Assuming lawns need cutting 30 weeks per year, this would be $56,250 per year. A durable, low-maintenance robotic mower could be a very savvy purchase for a planned development, even if the upfront cost was > $75k.

Major golf courses spend millions of dollars annually maintaining grass. Replacing some employees and heavy equipment with small robotic units offers huge cost savings to them.

A robotic lawn mower does not have to carry huge battery banks. In cases where noise is not an issue, a small ICE generator could greatly extend the cutting capacity and reduce the up-front cost.

Fish

[Gotwind Ben]

I really like the idea of an electric robotic lawnmower, particularly with GPS guidance and can see this of great benefit/cost effetivness for Golf courses and the like.
The only floor in an otherwise great idea is the collection of the grass cuttings :?:
Imperative on a golf course I suspect?, maybe not, I don't know.

Maybe the robot could have a collection box and 'return to base' to empty the cuttings every so often. all takes extra power however.Not impossible to overcome I suspect.

Civilian GPS doesn't work so good for something like that. You can get your lawn mower some spatial awareness better with more localized equipment, like they use inside buildings.

[Gotwind Ben]

I thought that may be the case Matt.
Rather sadly with some free time I 'walked' my TomTom sat Nav unit aroud our 1 acre site, and it barely registered any movement, hardly proof, but possibly a guide to current 'civilian' GPS accuracy.

These are all things that could be overcome if interest was high enough, savings of millions $ may prompt development I suspect.
However, the downside in a good way,
I can imagine Tiger woods face, as he takes a final putt in a major championship and a darn Gotwind solar 'mowbot' knocks his ball off line, the PR would be fantastic :D