How to Determine What Wattage of Solar Panel I Need to Choose
Hello! I welcome you on the board. we'll talk about the Solar Panels and it wattage to choose the solar panel according to the need of time. The performance and efficiency of a home power plant directly depend on the correct choice of solar panel characteristics. Innovative technology has made it possible to create a record 400 watt solar panel, which is currently the most efficient and economical. To determine the number and capacity of solar panels, it is necessary to accurately calculate the total energy consumption and choose the right type of panel.
Choose the Type
To determine the number and capacity of solar panels, it is necessary to accurately calculate the total energy consumption and choose the right type of panel. There are 2 main types of solar panels:
- MonoCrystalline.
- PolyCrystalline.
MonoCrystalline panels have great performance but only work when exposed to sunlight at an angle of 90 degrees. It is more efficient to install them in large solar power plants, where high output is important.
Polycrystalline panels work at any angle of inclination of the sun but have lower productivity. This type of module is more suitable for installation at home since they have a lower automatic start threshold.
Define the Brand
If it is important to you that your solar panel works efficiently and for a long time, take a closer look at the manufacturer's brand. Choosing the right company will provide you with excellent product quality.
It is best to choose from the "Tier1" list. Here are the top manufacturers from all over the world. As of 2020, the leading companies were:
- Jinko
- LONGi
- Solar
- Risen
- Trina
- QSells
- Talesun
- Astronergy
- Jinergy
- LG
Calculate the Power
After you have chosen the type and manufacturer of solar panels, you should proceed to the most important step - calculating the power. To do it, you need to know exactly how much power you are using. There are two ways to do this:
- Check data on meter readings (less accurate)
- Independently calculate all electrical appliances, their power, and operating time. This way, you can get the most accurate result.
Also, you need to add about 20-30% to the resulting value. This is the energy consumption of the inverter and the accumulator of the battery itself.
After that, you need to look at the indicators of solar radiation for the required city. For example, this figure is 0.8 for winter and 5 for summer.
For solar panels to operate at full capacity, it is important to receive direct sunlight at an angle of 90 degrees. This figure cannot be achieved throughout the day. Thus, solar panels can only function at 30-70%, depending on the region of location. Also, you should keep in mind that the panels produce energy only during daylight hours, which, in the summer period, are approximately from 8-9 a.m. to 4-5 p.m. In the autumn-spring and winter period, this number decreases significantly. The panels do not function at night but accumulate energy generated during the daytime.
Follow the Formula
The formula for calculating the power of a solar panel looks like this:
W = k*Pw*E.
- Where «k» is a fixed index – 0,5 in the summer period, and 0,7 in the winter period
- Pw – the power of a battery;
- E – solar radiation index for the selected period
If there is a 310-watt solar panel, and the solar radiation index is 0.8 for winter and 5 for summer, then
W = 0,5*310*5 = 775 watt per hour in summer
W = 0,7*310*0,8 = 174 watt per hour in winter
For example, you have calculated the total energy consumption of your house and got 6,000 watts. Also, we have to add approximately 30%. So, we receive 6,000*1,3 = 7,800 watts.
Now, we have to divide the total energy consumption on the W index: 7,800/775 = 10; 7,800/174 = 45. So, to cover all your needs, you have to install 10 310-watt solar panels in summer and 45 in winter.
Thus, based on the results of calculations, you can independently adjust the area and power of solar panels. Everything depends on your needs and desires.