The amount of energy your solar panel will produce is rated by watts. For example, if your solar panel is rated 100 watts, then on a clear day, your solar panel will produce 100 watts per hour. To find out how much electricity you need to produce, look at your electric bill and divide the total by 30 days and then divide it by 3 as there is generally bright sunlight one third of the day.
MY SOLAR TEST I DID WITH MY VAC TUBES ALSO SHOWED HOW I BUILT THEM.
It is always best to install your solar panels where they will get the most sunlight each day. It is important to check regularly for trees that may be overshadowing solar panels due to growth.