Designing a DIY Solar power or solar lighting kit

Over the next few pages we hope to help you understand how to design your own solar power kit. We really want to make it easy for you to help our very precious planet so if,  during the course of reading these pages you have any questions please don't hesitate to telephone or contact us - We are always pleased to help!

Calculating your energy requirements

Before anything else you need to calculate the power requirements of all your electrical items, so that's where we are going to start.

The power rating of appliances is usually given in Watts. Find this value by looking in the user manual or finding its identity sticky label. Some manufacturers give this figure in volt Amps which is written 500VA. This is exactly the same as Watts because Watts are always volts times Amps or V*A which is shortened to VA.  

The daily energy consumption for an electrical item is calculated by multiplying it's power (Watts or VA) by the number of hours per day it is used for:-

Repeat the above calculation for all the items you want to run using your solar power kit and total them up. Using the above as an example we need 240Watt hours for the computer and 300Watt hours for the lamps. That makes a total of 540 Watt hours or 540Wh

Why use Watts? Well, it always represents the power of an appliance regardless of the voltage. This is important when desiging a solar power kit because you could have a mixture of low voltage components (12V Lamps and batteries etc) and mains voltage items. Don't worry if that last sentence flew over your head at great speed because it will become clearer on the following pages!

     Solar kit - Power and batteries