How to design an off grid solar system ? Three steps

1 How to Choose right power of anoff grid inverter

The power of off grid inverter confirmed based on the user's load type and power. Household loads are generally divided into inductive and resistive loads.

Washing machines, air conditioners, refrigerators, pumps, range hoods and other loads with electric motors are inductive loads. The starting power of the motor is 5-7 times of the rated power. When calculating the power of the inverter, the starting power of these loads should be considered. Here is an example: One air conditioner is 800W, the Power of the Inverter at least 4000W

Televisions, electric fans, electric lights, etc. are resistive loads. As long as the sum is ok. For example, TV 200w, electric fan 200w,  400W Inverter will be okay

It should be emphasized here that not all loads are used at the same time, so the power selection of the off-grid inverter is flexible.

2 How many solar panels we need?

Then we should know how many solar panels we need.

You should know your own electricity consumption. For example your daily power consumption is 20KWH. How to calculation of your daily power consumption?

First if you have an Electric meter, you can read your electric meter, it is very accurate

If you do not have an Electric meter, you can estimate.

For example a TV 200W, working 2 hours per day. It is should be: 200W*2h=400WH=0.4KWH per day, same for other loads. At last add them together

For example your daily power consumption is 20KWH. Different places, different size of solar panels. In China, about 5KW solar panels will be okay.

At this step, Greensun solar engineer team will provide right size and numbers of solar panels for you

3 How to Choose Batteries?

If your stand alone solar system mostly used in day time, batteries capacity can be less, if all used at night should be more.

For example your daily power consumption is 20KWH, may 15KWH batteries capacity may be okay. If all used at night, at least 28KWH( as batteries deep cycle at 70% best)

For more questions.

Please email to Greensun Solar Engineer Peter: Peter@greensunpv.com