I LOVE Solar Tea. This looks like a potentially safer and year-round alternative.
If you love iced tea and are crunched for time, consider refrigerator brewing your next batch. Simply add loose tea or bags to a container, add water, place a tight lid on top, and leave it in your fridge for 12 hours.
Over the years many people have made sun tea by placing glass containers with teabags out in the sun instead of in the fridge. Sun tea is a boon during the summer when no one wants to boil water to add to the temperature of an already-hot room. Research articles have reported a risk of sun tea developing bacteria that might make you ill, so you should consider refrigerator tea as an alternative way to make hassle-free tea that doesn’t heat up your kitchen and has less chance of making you sick.
Keep in mind that tea prepared in the fridge can go bad if you keep it too long or practice unsafe food handling skills according to Evanor Tea. Discard the tea if it ever smells sour, gets thick, or you see ropey strand-like particles; these are signs that unwanted bacteria have spread even in the less-hospitable environment of your fridge.
Sunshine Tea and Refrigerator Tea | Cooking in Japan