Solar Power Calculator


Solar Power Calculator


When attempting to identify how to use solar power either at home, maybe whilst out camping or when using a caravan or boat the last thing you want is to suddenly find you are without power. There is no hard and fast rule to calculate your exact energy consumption and thus the level of solar equipment you will require to meet those need, however you can use our solar power calculator to get a good idea of how to proceed. Firstly make a list of the appliances you intend to use with your solar panels. To get some idea of power consumption have a look at the following table.


Using the appliances below, the solar power calculator suggests that you will be using 500W of solar energy a day. Now in order to meet that need, based on say the sun shining for 5 hours a day, you would require 100W solar panels that would then generate 100W per hour (100W x 5 hrs = 500W of the required consumption.) This energy would be stored in a leisure battery for use over the longer period. Please note; solar panels do not hook up directly to your appliances but to your leisure battery that can either power 12V appliances directly or, using an inverter power, your mains electric appliances.


In the diagram (above, top) most solar panel kits come complete with a charge controller to regulate the flow of power to ensure no sudden spikes. By charging during daylight/sunny hours, your battery is then topped up for the power to be used as required during other hours. When using our solar power calculator remember that you don't need to go 100% solar all at once. You may want to start off with say, 40W solar panels to power one item, then later, as you gain in confidence ~ or as your budget allows ~ add more solar panels for more equipment and join them together later. It really is that simple. In fact, its an approach we would recommend.



Name of appliance

Typical Power ConsumptionNumber of hours use per dayCalculation
Laptop Computer50W  
19" Television65W  
12" Television20W  
12V Cooler40W  
Stereo System50W  
Clock Radio10W  
40W Light10W  
LED Floodlight12W  


Now, to use the solar power calculator simply multiply the typical power consumption by the number of hours per day to identify the power required. For example:


Name of applianceTypical Power ConsumptionNumber of hours use per dayCalculation
Laptop Computer50W3150W
40W Light10W440W
12" Television20W480W
12V Cooler40W5200W
Clock Radio10W330W
TOTAL  500 W



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