Among the many projects I've wanted to take on for some time is making some provision for electricity if the grid is down for an extended period. (It does happen, in the 2002 ice storm power was out in this house for 8 days.) I have a generator, and generators are a wonderful thing--until the fuel runs out. My little Honda is a fuel sipper, but if things drag out long enough, the gas supply will run out. In the case of a multi-day outage my plan is that the generator is for powering the fridge and the freezer a couple of times per day to keep the food from spoiling, and maybe an hour or so at night. That ought to stretch the fuel out for literally weeks--long enough to use up the cold stuff.
However, that leave many nagging needs for electricity that remain unsatisfied. Lights, TV/radio and all manner of other things want electricity to run. (Yes, my preparedness plans include some level of creature comforts. My ancestors didn't move out of the caves just so I can move back in.) You can substitute battery-operated appliances, but you can only keep so many batteries. And trust me, in the event of a prolonged power outage, you and a zillion of your friends and neighbors will all be combing every store around for replacements. Not a good situation to find yourself in. Besides, what if instead of an ice storm, it's the Dread Nonspecific Pandemic that has lead to a grid-down situation? You really don't want to be out there with the infected and potentially infected, do you?
A solar setup large enough for the entire house (a traditional off-the-grid type setup), is economically out of the question. I've considered a more limited setup, but the price and complexity are still far more than I'm willing to deal with. So my research has turned to alternative solutions such as the various sorts of solar battery chargers and self-contained kits.
There are a number of solar "trickle chargers" like this one for vehicle batteries. They're meant for times when you've parked the car for a long period, and you want to keep the battery topped up. At 2-6 watts, they aren't going to recharge a heavily used battery very quickly. That doesn't make them much good for my purpose. Still, I might buy one of the largest ones as a backup.
Then there is this interesting 10 watt "high speed" solar battery charger, that has the added benefit of being able to power some smaller 12 volt devices. It can charge AAA, AA, C, D or 9V Ni-Mh batteries at a max of 600 mA (I assume that's per hour). That means if you charging 4 1800 mA AA batteries, it's going to take at least 12 hours. Doable, but you're going to make some hard choices about where the batteries are used, unless you buy several. At $170 each, that could get expensive.
PowerFilm has a line of flexible solar panels in sizes up to 18.5 watts (15.6 volts @ 1.2 amps). They're made with marine-grade components. Somewhat expensive (around $400 for the 18.5 watt model, without accessories), but we're getting up to a usable size, and the portability aspect could be useful.
There are also kits designed for the RV/boating crowds. Go2Marine has this 110 watt kit for under $1200. You'd still have to add mounting hardware and batteries to that. Another company, ETA Engineering, has several kits that have everything but the batteries.
The last option I've found is the seller everyone loves to hate (but uses anyway), eBay. In their "Alternative and Solar" category, you can find just about everything except the wire to set up a complete solar system of about any size. Cut down on the number of panels and batteries, and you can roll your own solar setup. Intriguing, and it makes reopening the previously dismissed small off-the-grid system more attractive.. But remember, it's eBay. Watch the prices, the shipping and the feedback ratings. The saying "caveat emptor " may have been invented for eBay.
I haven't arrived at a decision yet. I'm really attracted to the roll-up panels, but the attraction of being able to do a less portable but higher power and better bang-for-the-watt may be the deciding factors. Considering that our primary plan is to bug-in rather than bug-out, it makes a lot more sense. At any rate, whenever the time comes, expect blog posts and lots of pictures.