Basically, you don't really need the sun to make tea. If you steep bags in a jar of water, the liquid readily becomes tea. The sun does help to deepen the flavor, however, releasing more of the essential oils of bergamot, lavender, lemon, orange, or whatever you have added to your tea.
Some recent flavors we've attempted are:
Green lemonade (green tea and lemon zinger)
White peach (white tea and peach puree)
Some we are going to try soon:
White raspberry lime (white tea, raspberry puree and lime juice/rind)
Chocolate mint (we have a chocolate mint plant in the yard)
To make sun tea:
Use a clean, quart or gallon sized jar. Fill it with water. Add tea bags to your liking. I usually add about 6-7 bags for a gallon jar, but we like it really strong. after the tea has brewed in the sun for around 4 hours, you can sweeten it to taste. You can also keep it unsweetened (of course!) and sweeten it per glass - or not at all. We keep ours refrigerated. This will keep for days, though I'd be surprised if it lasted that long!