Getting off the grid at home is beyond my retirement income but I’ve managed to use the sun to banish the infernal combustion engine from my workshop.
An extended power blackout a few years ago prompted me to invest in a small portable solar setup which enables me to charge mobile phones and a laptop and to provide lighting and radio. It’s proved a boon for camping and with a 50W solar panel I now use only free solar energy to mow my lawn.
With the ever-increasing cost of petrol the cost of running a conventional lawnmower is becoming more significant. My running costs are zilch.
Here’s the setup:
The solar panel
This is a 50W portable folding panel. It folds up into a bag a little bigger than a briefcase.
The solar panel charges the:
12V deep cycle battery
These are at least twice the price of an automotive battery but are necessary for solar setups. Automotive batteries are designed to output high power over a short period but not to be discharged too much. I have 4 of these connected in parallel but you can get by with just one. Extra batteries just give you a longer insurance against too many cloudy days.
The battery is connected with a couple of alligator clips to the:
DC to AC Inverter
This converts 12V DC current from the battery to 220V AC current. I’m using an inexpensive 300W square wave inverter but before my next camping trip I’ll be upgrading to a more expensive 1000W pure sine wave inverter which will allow me to use fluorescent lighting and any other devices which aren’t happy with the square wave output of the cheapies.
The plug you see in the inverter output is for the charger for:
The lawnmower battery
It would be more efficient to charge this battery directly from the solar panel but the mower battery consists of 2 x 12V batteries wired in series to output 24V. It would be a hassle to disassemble it every time it’s charged so it’s more convenient to go through the inverter.
And the charged battery fits into the:
A note about the Enviromower
My last one lasted 8 years. If I’d been more careful about keeping the mower dry and regularly sprayed the electrical connections on both mower and battery with CRC it probably would have lasted at least twice as long.
This mower handles my average sized suburban lawn with one charge as long as I don’t let it get too long.
I have about a 750 square metre ( ⅜ acre) property as shown below. I’d recommend this setup for up to a ¼ acre – you’d need an extra battery – but the mower blade is only 350mm (14″) diameter so a bigger area would be a challenge.
But wait! There’s more!
Stihl have a great range of 36V battery operated tools with interchangeable batteries which are surprisingly powerful. I have the line trimmer and the yard blower and I’m very impressed with them. My 300W inverter manages to charge these too – barely. The Stihl 36V charger is a fast charge high drain device so you really need at least 500W.
I’ll probably be hocking off my firewood chainsaw on Trade Me and replacing it with an electric one in this range.