So how do we determine how many Amp Hours a given solar panel can produce in an hour? The answer is to look at the Amperage ratings for each solar panel which are published by the manufacturer. For instance, the Kyocera KC-130 can produce 7.39 Amps maximum in ideal (sunny/clear) conditions. Therefore, it has the ability to produce 7.39 Amp Hours (per hour). Take note however that these are the maximum ratings, meaning that under perfect conditions of full sunlight with no clouds this panel will produce 7.39 Amps. Here in sunny Phoenix, Arizona we are likely to see perfect conditions most of the time. If you live back east however, the days are often cloudy and you will not see consistently sunny days. Since this is an extremely tough thing to factor into the equation, you are going to have to try to take it into account and plan as best you can. It is for conditional reasons like this that you will never really know if the system you plan to install will meet your needs until you are able to test it out in reality and is why I have suggested leaving some head room in the equipment that you purchase in case you need to add additional panels down the road.

Once we know how many Amp Hours a solar panel can produce in one hour, we need to know how many hours of sunlight this panel is going to receive per day in order to calculate approximately how many Amp Hours it will produce over the course of a single day. Depending on where you live and what time of year it is (summer/winter), will determine how many hours of sunlight you receive and how many total Amp Hours a solar panel can provide in one day. 

Provided below is a chart that will help you to estimate how many hours of sunlight you can expect in your region. The “High” number reflects the amount of hours of sunlight you can expect to receive in the summer while the “low” number reflects winter time. The average is just that, an average of the two. If you only plan to use your RV during the summer months, then you can probably use the “high” number. However, to err on the side of caution, and to reflect the fact that not every day is perfectly clear, I suggest you use the Avg number.

Sun Hours per Day

Getting back to our calculations, we know that you need to replace 100 Amp Hours a day and we have determined that our Kyocera KC-130 can supply approximately 7.39 Amp Hours (per hour) in ideal conditions (no clouds, etc).   Let’s assume that you live in Phoenix, Arizona.  Using the chart above, you can determine how many Amp Hours this panel will produce in one day based on the amount of hours you can expect to receive sunlight.  Below are three calculations using the high, low, and average numbers.  These calculations are for one KC-130 solar panel.

• High (summer) = 7.13 hours sunlight x 7.39 AH (per hour) = 52.7 Total Amp Hours a day
• Low (winter) = 5.78 hours sunlight x 7.39 AH (per hour) = 42.7 Total Amp Hours a day
• Average = 6.58 hours sunlight x 7.39 AH (per hour) = 48.6 Total Amp Hours a day

Therefore, if you need to replace 100 Amp Hours a day, you are going to need:

• Summer = 100AH / 52.7 AH a day = 1.89 (2 panels to meet your needs)
• Winter = 100AH / 42.7 AH a day = 2.34 (3 panels to meet your needs)
• Average = 100AH / 48.6 AH a day = 2.06 (2 panels to meet your needs)

Knowing that you need to replace approximately 100 Amp Hours a day, you can safely assume based on the calculations above (if you are doing mostly summer camping) that you will need approximately two KC-130 panels to replace the 100 Amp Hours you are using per day. If you plan on doing a lot of winter camping however, you either need to cut your consumption down or get an additional solar panel to make up for the difference.

Still scratching your head? Confused? Let’s do another example. Let’s assume that you have determined that you need to replace 80 Amp Hours a day, you are thinking of using Kyocera KC-85 solar panels, you live in Portland, Maine, and you want to determine how many panels you will need for your RV. Based on Kyocera’s published specs for this panel, it can produce 5.02 amps under ideal conditions. Therefore it can produce 5.02 AH (per hour). Since you live in Portland, Maine, the total Amp Hours produced by one panel based on the sunlight hours per day chart above are as follows:

• High (summer) = 5.23 hours sunlight x 5.02 AH (per hour) = 26.3 Total Amp Hours a day
• Low (winter) = 3.56 hours sunlight x 5.02 AH (per hour) = 17.9 Total Amp Hours a day
• Average = 4.51 hours sunlight x 5.02 AH (per hour) = 22.6 Total Amp Hours a day

Therefore, if you need to replace 80 Amp Hours a day, you are going to need:

• Summer = 80 AH / 26.3 AH a Day = 3.04 (3 panels should meet your needs)
• Winter = 80AH / 17.9 AH a Day = 4.46 (5 panels to meet your needs)
• Average = 80AH / 22.6 AH a Day = 3.53 (4 panels to meet your needs)

In my situation, based on the calculations I did when I was planning my upgrades, I decided on three Kyocera KC-130 solar panels. Using the KC-130 panels, I have the ability to replace 171.6 Amp Hours worth of energy under ideals conditions in the summer. Since there is less sun in the winter, this is reduced to as little as 128.1 Amp Hours. Based on my real world experience once we hit the road, I have found that I overestimated the amount of energy that I would need to replace and although I left enough head room in my equipment to add an additional solar panel, I really don’t need to add any at this time.

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