The Electric Gardener: Part 3- The Solar Charge

Imagine this.  You’re all into the electric garden tools, maybe you have a little cordless electric mower and trimmer, maybe a scooter to get you out to the back 40 or a big, bad, battery-powered log splitter you converted yourself.  You get done mowing, trimming, wacking, scooting or splitting, you wheel it into it’s little shed, plug it in to the charger, and go have an icey tea.  Except the shed is a half-mile from the nearest outlet.  Two words- solar charging.

Timid about diving into solar power?  Don’t be.  Gone are the days when its experimental, crazy expensive and supremely technical. Saunter over to Northern Tool for an idea of what I’m talking about.  (No- they don’t pay me but I do believe they should, don’t you? )

Sunforce is a great company that manufactures and sells a broad array of products for solar energy and wind turbines.  They have all the accessories you need, and are a great resource for finding what’s out there and which products may be good for your needs.  They don’t resell from their site though, but they do sell through a variety of retailers.    If you sniff around you may be able to find a reseller who can give you some help making decisions, but Northern Tool has a great info page with a complete introduction to solar power systems- the Solar Power Buyers Guide.  That’s where I came up with the rig shown here.

This is the Sunforce 60 Watt Solar Panel with 7 Amp Charge Controller from the Northern Tool site, and includes everything you need to set it up, all for $500.  The panel generates the electricity, the Charge Controller converts the power into a voltage that you can use- it handles the voltage conversion and allows you to connect it to your charger.  The easiest kits are set up to charge 12V batteries, so you may want to set up a charging system that feeds each of your 12V batteries individually,  (in parallel), or you can go with a system that converts to 110V, so you can simply plug in your AC charger.  That’s probably the most technically challenging decision you have to make in the entire project.

The other decision you have to make is how much power (watts) you need.  The higher the wattage, the faster the system will charge up your batteries.  They have battery “maintenance” panels that really don’t charge much – they’re simply to keep the battery from self-discharging when not being used (often used on boats).  Those can be around 1 watt.  Bigger systems, 10W and the like, are “trickle chargers” that will charge up a battery slowly, over an extended period of time.  Those are great for tools like mowers that you use with as much as a week between jobs.  Batteries love slow charging by the way – they last longer and reach higher states of charge when trickle charged.

Bigger systems are perfect for higher load, when you’re charging several tools, or vehicles, at once.  Want to see my favorite solar shed?  Here you go – from the annals of ElMoto and the world of Juiced Drag Racing, Ed Fargo’s solar EV charging station:

This little clubhouse not only charges his Zap electric car and his two electric motorcycles, but 2/3 of his household appliances as well.  It’s running at around 2500W.  He’s my hero.

This is more what I was thinking, though:

My advice, start small, see how it all works without spending a ton of money.  You’ll learn a few things and the panels can always be ganged up with more, later, if you want to build up your capacity.

The secret to keeping it simple is avoiding the tie-in to the grid.  You can have the system feeding into your house power, and when you’re generating more power than you’re using it gets sold back to the power company, but that adds a level of complexity to the engineering.  You can, as Ed has, take the solar system on or off the house by a simple flip of a switch.  You can also, as my buddy Terry does, run the entire house off solar, charge the batteries during off-peak hours and turn around and sell the power back to the grid during peak hours when it’s worth more.

Or you can slap a panel on your doghouse and charge up your mower.

Want to read more about electric gardening?  Check out all the posts:  The Electric Gardener: Part One,  The Electric Gardener: Converting the Tiller, and The Electric Gardener: The Solar Charge, and The Electric Gardener- Sunday Morning Chain Saws.


3 responses to “The Electric Gardener: Part 3- The Solar Charge

  1. Pingback: The Electric Gardener – Part One « The Electric Chronicles·

  2. Pingback: The Electric Gardener- Converting the Tiller « The Electric Chronicles·

  3. Pingback: The Electric Gardener- Sunday Morning Chain Saws « The Electric Chronicles·


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