When buying a solar water heater, it is likely for you to be confused about the capacity of the heater. Don’t worry though. It depends on the number of people who would access hot water. If you have only 2 people in your home, the 100 liters capacity would likely suffice. But, in case you have more, it is better that you enhance the capacity too. This is all dependent on how much water you will access and how much water you will need to stay hot for the other people to use at home.