Israel started using solar energy before it became trendy. For hot water. Pretty genius, right?

The country only supplies cold water through the central system. But you've got scorching sun almost year-round (especially in summer) that's really good at heating everything. That's exactly what you need: if you look carefully at rooftops even in big cities, you'll notice water tanks. Heated by the sun alone. The output temperature is actually scalding—I checked it myself. Even when it's just 25°C outside.

For bad weather days, sometimes they install a backup option like a boiler or instant water heater. But usually you don't even need them.