Designing a renewable energy system requires answers to the two most basic questions. What do you want to do and how long do you want to do it? In other words, you need to know the amount of power (kilowatts) needed to power your electrical devices and the amount of energy (kilowatt hours) it takes to keep them running throughout the day.

The answers determine the most economical configuration for renewable energy generation as well as storage capacity to hold and manage surplus generation and off-peak (low-cost) grid electricity.