What's the application? I like messing with everything from whole-house photovoltaic systems to cookers and portable LED lights. We installed our first PV setup in 2005 for a small house that's now a rental. When we moved to a bigger place, we installed a 4.4 kW PV system that's grid-tied (excess power goes to the grid and is credited).
In 2009, I built a greenhouse that's about 95% solar powered, with a flat-plate collector feeding a heatsink under the floor, with the water pumped through a maze of tubing. The thermal mass (3 ft. of sand) stays above 55°F all winter.
Here's a GoSun solar oven made from evacuated glass tubing (like a thermos bottle) with a 12V heating element so you can go on cooking during a storm or after dark.
These LED lamps are charged by a small PV panel and provide useful light for up to 72 hours.
If you've never worked with solar stuff, start with a few LED lamps, a small battery charger, or a solar attic fan, just to get the hang of it.
