Sunday, October 15, 2017

Rethinking Solar Power On A Budget

My OLD Solar Power Setup


I bought my first solar panel in the mid-1980s to provide a small amount of power to the battery bank on my 23 foot sailboat.  It was overly large, anemic in power generating capacity, and expensive.
Eight years later I had upgraded to a bigger boat and a bigger solar panel - and while still expensive - this new panel put out a good deal more power (a whopping 40 watts).
That 40 watt (2 foot x 4 foot) panel was almost $800, and while ridiculously out of date by today's standards, I still have it.  You can see a simplified schematic of how I have it set up at the top of this blog.  For a full description, you can revisit my 2011 blog Solar Power Preparedness On A Budget.

Today, you can buy comparable 40 watt solar panel for less than $100 (sometimes less than $60 on Amazon), and they are about 1/3rd the size of my old panel. Add a 12 volt battery ($50-$100), a solar charge controller ($10-$20) and a small inverter ($20) and for well under $200 you can put together a pretty good solar power system.
No . . . you won't be running  your refrigerator, or air-conditioning, or big screen TV with that setup, but you can charge cells phones, tablets, and lap top computers - run LED lights - and a 12 volt fan
Ask anyone in Texas, Florida, or Puerto Rico who either are, or were, without power and I think they would all welcome even those small creature comforts.  Of course, if you add more (or larger) solar panels, and more batteries, you can do a lot more.

Where you live will make a difference on how much juice your system will provide. Here in sunny Florida, we average 6 to 7 good charging hours a day.  If you live in Vermont, or Minnesota your power generation will be a lot less - but a larger setup might still be feasible.

I don't leave my panel out full time.  I keep my 12 volt battery on a trickle charge, and only pull out and hook up the solar panel if I need to.  I've wired in a 12 volt plug with 2 USB charging ports to some clamps (see photo below) which can either charge USB devices directly or run an inverter.

The trickle charger was $8, the small (80 watt) inverter was less than $20.  The larger inverter was about $30. The only real disadvantage to this system is its weight and bulk, and the difficulty I had taking it with me when I had to bug out last month due to hurricane Irma (see A Post Irma Update).
None of this is terribly difficult to put together, but believe it or not, there is an even easier way.
Over the past 10 years we've seen a USB revolution.  USB ports - which are used to charge nearly all cell phones, tablets, and a growing number of peripherals - have become the new power standard.  Instead of 12 volts, these device run off 5 volts - and with the availability of cheap, rechargeable USB power banks, you can eliminate the heavy 12 volt lead acid battery shown above.

Better yet, there are USB specific solar panels that charge these 5 volt batteries, that are smaller, lighter, and often cheaper than the 12 volt system described above.  Yes, you give up the ability to run a 120 volt inverter, but the growing array of 5 volt peripherals makes that less of a concern.
For most of us, the priority during a prolonged power outage will be cell phones, tablets, radio, LED lights, and (particularly in the south) fans. And 5 volts will do all of that and more.
I've just started my conversion over to 5 volt solar charging (and I'll keep my old system, since it still works), so I'm hardly an expert. The most basic system (see photo below) can be put together for about $40.

A 10,000 milliamp battery with (3 fold) solar panal, a USB fan, and USB LED light.
The beauty of this system is it will fit in a backpack, weighs about 2 lbs, and while the solar charging will be slow and you'll have to be judicious with their use, it should keep phones, lights, MP3 players, and fans going for a few days.  Longer if you don't need the fan. 
For under $100 you can buy a couple of bigger power bricks, and a much larger solar panel (20 watts plus), which will increase your capabilities significantly.  That will be my next step.
The common denominator in most natural disasters is that the power will go out.  For most people, that will amount to but a few hours inconvenience. But for millions in Texas and Florida this summer, that meant days of sitting in the dark.
And for nearly 4 million people in Puerto Rico, that is going to mean months. 
While a $40 or even a $200 solar power system won't eliminate all of the pain of going without power for days or weeks, it can help make a bad experience a little more tolerable.

And for the price, that's hard to beat.

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