There are a number of solar laptop chargers on the market, but not all of them are created equal. This is a helpful overview of some of the products available and what might work for you.
When looking for a solar powered charger for your laptop, size is a big concern. You want something small, handy, and light. In this day and age of smaller, lighter technology, it is tough to think that any great product might not be pocket-sized. In the realm of solar chargers, however, size has not yet been conquered. They range from slightly smaller than a briefcase to beach blanket size, about 14 inches to over 40 inches. The Voltaic Generator is one example of a great design idea, but the added weight and size of the bag to your laptop weight could be a big deciding factor for you.
Most solar powered chargers do provide a decent amount of power. Power ranges from 10 to 30 watts. That's a fairly wide spectrum, I know. In most products, there is a direct correlation between size and output. If you don't need something with loads of power and portability is your biggest concern, check out the SolarRoll by Brunton. As the name suggests, it rolls up. The smallest one for laptop use puts out 14 watts. That's enough to charge your laptop completely in around 10 hours or extend your usage quite a bit.
The price tag on solar powered laptop chargers may be enough to turn you off completely. Remember the price of electricity when considering this purchase. If you were able to charge your laptop each day with a solar charger instead of plugging it into an outlet, you could save yourself a couple hundred dollars a year, especially with an older laptop. Some of the most exciting solar powered charger designs are still ringing in around the $500 range. There are options for around $100, though. They usually are not as pretty or convenient as their pricier counterparts, but this Portable Briefcase Solar Generator is a pretty good, inexpensive option. There are even backpacks that are solar powered for about $200. Another affordable option is to make your own solar powered laptop charger. You can read more about that here.