Grid Down Solar Solutions On A Budget

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Later today California's PG&E - for the 3rd time in 3 weeks - will shut off power to a large area of Northern California, in an attempt to avoid sparking additional wildfires during a forecasted  high wind event.  

As many as 2 million customers may be without power for 48 hours or longer.  And by the look of things, this is a problem that is likely to be repeated  for years to come.

Having been a user of solar power for more than 30 years, including in off-the-grid settings (aboard two cruising sailboats), and living in Hurricane country, where prolonged power outages are common, I've crafted some inexpensive solar power hacks to make life more bearable when the grid goes down.

No, I don't have a $30,000 whole house solar setup; one which feeds power back to the electric company for a credit on my power bill.  While that may make economic sense for some, it isn't practical for me.

And most of those setups lack one all-important ingredient; a way to provide power to your home when the power grid is down.  Without a charged (and solar rechargeable) battery system, even with thousands of dollars worth of solar panels on your roof, you're dead in the water.

The argument against maintaining a battery bank has always been the cost (often $10K-25K), and the fact that they require maintenance, and can wear out over time.  For most people that doesn't make sense.

But that is only if you want to run your whole house (still, only for a limited number of hours), off your solar-rechargeable batteries. There are solutions for a fraction of the cost, that can at least run LED lights, fans, radios, and keep your cell phones, tablets, and laptop computers charged.

No, you won't be running your A/C, or big screen TVs, freezers or refrigerators.  But you won't be dropping $25K to 50K, either. 

At its simplest, a solar panel battery setup is very easy to build.  You can buy everything you need for $200 to $300, and can install it in a day.  As shown below, all you will have is a 12 volt power source (battery), but add a cheap inverter, and you can have 120 volts. 

Most solar panels generate 14 to 17 volts, enough to charge a 12 volt battery, and their ability to charge is rated in watts. A small 15-watt panel generates 15 watts of electricity at roughly 15 volts each hour. This is roughly the equivalent of 1 amp of charging per hour into your battery. 

Larger (more expensive) panels may produce 30, 40, 80, 120 watts of power (or more). For each 15 watts, think (roughly) 1 additional amp/hr. A 60-watt panel would therefore generate about 4 amps per hour during prime sunlight hours (usually about 5 to 6 hours a day).

The very good news is the cost of solar panels has dropped dramatically in recent years. You can often find a 100 watt panel now for less than $1 a watt. Figure another $100 for a deep cycle 12 volt battery, a $20 charge controller, and a $30 inverter, and you've got a bare bones system.

You can, of course, expand this system with additional solar panels, a bigger bank of batteries, and a more powerful inverter. A substantially more robust system might run you between $500 and $1000. 

Or, if your needs are modest (as are mine), you can go even smaller.

Earlier this summer I wrote about some less powerful off the shelf solutions, and detailed how I built a sub-$100 battery backup for my home (see Preparedness: Some Emergency Power Solutions).  Some excerpts from that blog:

The first, easiest, and least expensive option is to buy one or more solar powered USB batteries (see below). While the most limited in terms of what they can power (and for how long), these are ideal for those who need a light weight bug-out friendly solution, or for anyone who isn't comfortable with the more complex systems that follow.

Battery, Solar Panel, Fan & Light - About $50.

A 10,000 milliamp battery with (3 fold) solar panel, a USB fan, and USB LED light. The beauty of this system is it will fit in a bug out bag, 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, Tablets, MP3 players, and fans going for a few days.  Longer if you don't need the fan.

 

(Note: Newer products now have 20,000 and 25,000 milliamp batteries and larger (4 fold) solar panels)

Following our recent week-long power outage from Hurricane Irma in 2017, I've given this exact setup to several friends. It's cheap, lightweight, and dead simple to use. I have a couple of them myself, tucked in my bug out bags.

Following Irma I've also built a couple of `portable' power banks, which I keep constantly charged using a trickle charger. These weigh about 30lbs each, so they aren't exactly `backpack friendly',  but they provide considerable more power than the USB batteries pictured above.

Although a full sized deep cycle battery can be used, to save my aching back I've elected to go with smaller, lighter, and less expensive lawn mower batteries. I built two, which allow me to charge one (using a solar panel), while I draw power from the other.

Note:  Solar power purists right now are probably foaming at the mouth, as the standard lead-acid batteries I'm using are not ideal for this type of system. And if I were designing a permanent off-grid system, I would agree. But this is for emergency standby power, not long-term use, and so I've elected to go with the most accessible, and least expensive options.

I keep these on a shelf on my (well ventilated) screened lanai and check the water levels every few weeks. In two years, I've added distilled water once.

Small (10 watt to 20 watt) solar panels can be had for under $40, which should be adequate for the smaller batteries. If you go with the bigger deep cycle batteries, consider getting a bigger panel with a charge controller.

While none of these solutions will provide enough power to run major appliances, central heat and air, or other high wattage devices, they can make life a little easier when the grid goes down.  

And you'll be surprised how much you'll appreciate the simple things - like having lights, a fan, your cell phone, or a radio - after the grid has been down for 24 hours. 

And you don't have to live in California, or in hurricane country, to find yourself unexpectedly in the dark.

Between our ageing infrastructure (see ASCE report card on America’s infrastructure), natural disasters like earthquakes and severe weather, disruptions caused by solar flares (see NASA: The Solar Super Storm Of 2012), and even cyber attacks (see DHS: NIAC Cyber Threat Report - August 2017), the odds are that a prolonged outage is in your future. 

Not quite a year ago, in NIAC: Surviving A Catastrophic Power Outage, we looked at a NIAC (National Infrastructure Advisory Council) 94-page report that examines the United State's ability to respond to and recover from a widespread catastrophic power outage.

https://www.hsdl.org/?view&did=819354

While the solar hacks presented above won't make life luxurious during a prolonged power outage, the could make life a little less miserable.  And that, to me, is worth doing.