How do I determine the most appropriate solar thermal storage size?

Q: How to determine the best solar thermal storage size.

A: Choosing your storage tank size is dependent on three things. 1- the number of ft2 of collector- for example we typically recommend any where from 1-3 gallons of storage per ft2 of collector,   2- the daily load profile (usage pattern) for example if most of your usage occurs in the early morning or in the evening, then you would not adjust your storage ratio. However, if your usage occurs more in the mid-day then you would reduce your storage ratio because you will be consuming that which you are producing, therefore saving energy can be a moot point  3- the required temperature. For example the colder the required temperature, the more storage you can have per area of collector. If you need some really high temps for baseboard heating then your storage ratio will be 1:1 or less. But if your required temperature is 100 degrees F then you can maximize your storage capacity with, say, a 3:1 ratio.