How to choose a solar system of the right size

  In today's society, solar power systems have become the choice of most people due to their cleanliness, self-sufficiency and convenience. However, before setting up power generation system, I believe many people are troubled by the question of how to choose a suitable solar power system. If you are also troubled by this, then this article will completely solve your confusion.

【The two required data】

  To calculate the wattage of your solar system you need two figures: the average amount of electricity you use per day and the average number of hours of sunshine in your area. The electricity figure you can check from your own energy list to see how much electricity you have used in the past year (kwh) and divide by 365 days to get your average daily electricity usage. For the average hours of sunshine in your area, you can try the table below to find the data for your nearest city, or use a search engine (enter "average hours of sunshine in xx location)

【Average hours of sunshine in some cities】

London 4.38h
New York 4.46h
Berlin 3.04h
Chicago 4.41h
Washington 4.39h
Miami 5h
Los Angeles 5.91h
New Orleans 4.6h
Tokyo 4.2h
Warsaw 3.19h
Beijing 5.17h
Paris 3.45h
Melbourne 4.47h
Greenland 4.26h
Madrid 4.87h
Wellington 4.55h
Milan 4.01h

【Calculation method 】

  So next we can calculate the right wattage for your solar system. Divide your average daily electricity consumption (kwh) by the average number of hours of sunshine (h) to get the number of kilowatts (kw) required for your solar system (please don't forget to convert the units).

【Two calculation examples】

  For example, if you live in New York and check your electricity bill and find that you use 10,000kwh a year, then the average daily electricity consumption is 10,000kwh➗365 = 27.4kwh. From the table we know that the average sunshine hours in New York is 4.46h, which means that the number of watts you need for a solar system is: 27.4kwh➗4.46h = 6.143kw = 6143w. Then a 6000w solar system is the right one for you.

      Similarly, living in London and using 3000kwh of electricity a year, you would need 3000kwh➗365➗4.38h=1.876kw=1876w. So a 2000w solar system is right for you!

【Other ways to get your daily electricity consumption】

  So how do you get your average daily electricity usage if you power your own caravan, off-grid cabin, or for other reasons, have no energy bill check? Yes, you can get your daily electricity consumption (kwh/kw) directly by multiplying the rated power (w/kw) of the appliances you use each day by the time of use (h). The power rating of the appliance you are using can be found in the appliance manual, on the label of the appliance, and in the details of the Amazon where you purchased it. Also note that in this process you also need to pay attention to unit conversions: 1kw = 1000w, 1kwh = 1000wh.

【Common electrical appliance power and power consumption reference】

【Common electrical appliance power and power consumption reference】