He was fairly smart, taking those kind of things with him. Id put into a cellphone (which he can charge with the generator) blueprints/recipes to various technologies (be it mechanical or pratical, such as medicine making) and also bring seeds for food stuff like rice, soy, some fruits he likes and other vegetables.
Oh, and solar panels would be useful either way, be it to use during the day (reducing the burden on the hydro generator) or to charge battery based stuff (phone, laptop, flashlight, radio communicator...). Its not like you cant store solar energy into a battery as well; they sell the whole grid setup for home use.