Yes, a 'Solar Sail' in fact uses the solar wind as much as the pressure of light. Close to a star, the solar wind is much stronger. Farther out, the light would contribute more of the push. The thing is, it is VERY slow to build up speed and as everyone else has pointed out it can only work moving AWAY from the star. If there's one thing all races must have developed by the time this game occurs, it's space ship engines that let you go more or less directly from one place to another. Having to loop around a solar system a dozen times like the Cassini probe has been doing would be incredibly annoying.
There is a new type of 'Solar Sail' in the works, btw. It's totally dependent on solar wind since it's magnetic rather than a big sheet of pLastic or something like that. It turns out you can just create a big magnetic field around your ship and pump out some plasma into it. The magnetic "drag" of the solar wind hitting this works just as well as the physical "sail" type of propulsion but you don't have to worry whether it will get all tangled up when you try to deploy after launch and it won't get torn by micro-meteors. Otherwise it's still a solar sail and only works in one direction. Great for primitives like us to send probes into the distant reaches of the solar system. Not worth anything to anyone who has high-velocity propulsion systems already and doesn't have to loop-the-loop around the solar system to get anywhere.