One of the most popular types of portable solar panel systems is the 12 volt (12v) system.

But just how much energy does 12v generate you? Not enough to warm up your residence, but enough to run some of your portable devices, or reload their rechargeable batteries.

Because of their smaller size they generate a lesser amount of electricity but act just like a big solar panel. This type of solar panel works best under full sunlight. Most of them will work on cloudy and rainy days, but it will take longer to return the electricity to charge your device. This type of panel does not work with indoor light, but newer advances in cell technology are making indoor light a possibility to charge a small panel. Some have already reached the consumer market.

Great portable panel systems have built-in regulators, meaning they'll mechanically correct the amount of energy they make to the amount that the device requires. So be sure that the portable panels you buy have this feature, otherwise there's a risk of overcharging (or "frying") the contraption that you're trying to recharge.

You still need to be careful when handling portable solar panels , it's not like you can go swimming with them. If you fold or crease the solar cell itself, you'll likely break or disable it. So don't fold the cell, or put the portable panels in the washing machine, or prod them with sharp objects. Your weight belt will survive that kind of treatment, but your portable solar panel won't.

One more word of caution: the portable solar panel can't reload normal batteries. It can only charge rechargeable batteries. This may be obvious to you, but you'd be surprised how many individuals try to reload normal batteries.

You will need extra connector equipment in order to use the portable panels, so plan for the additional expense. You'll need connectors that fit with the recharging plugs on your portable devices. And if you plan to use your portable solar panels to trickle charge your car, boat or snowmobile battery, you might need a set of battery clips.

"Trickle charging" can keep your vehicle's battery completely charged. Here's how it works: place the portable solar panel on a surface where it receives the most sun; then plug it into the cigarette lighter socket, or attach the clips to the vehicle's battery. This can be a great help in really cold climates where temperatures drop below freezing, and you have to keep your car parked outside all day.

Portable solar panels are still relatively expensive compared to using grid electricity at home or in the office. But they make sense if you spend a lot of time camping, hiking or working from your car. And they're great backup systems for times when the power goes out.