With the popularity of renewable solar energy, more and more homes or factories and businesses are considering installing solar systems to reduce our electricity bills by generating electricity from photovoltaics for home use. This has led many people to wonder approximately how many solar panels are needed to generate 1000KWh of electricity per month.
The amount of electricity generated by solar panels per month is related to a number of factors, such as: the output power of each solar panel, the local sunshine hours, etc. It is calculated by the formula:
Monthly electricity generated by solar system = number of PV panels * output power of PV panels * peak sunshine duration * 30
Then some people may mistakenly think that the amount of power solar panels bought will provide the amount of power. In fact, this is not the case, the actual output power of solar panels is also affected by various factors. For example, temperature, dust stains on the panels, solar inverter and cable losses.
1. How many solar panels are needed to generate 1000KWh of electricity per month?
Here, a rough calculation can be made. Let’s say you have installed 400W solar panels and the local peak sunshine duration is 4 hours, ignoring other factors. One solar panel produces 48KWh of electricity per month, so it would take 20~21 solar panels to produce 1000KWh of electricity per month.
Analogy: If it is a 200watt PV panel, it needs 40~41 panels.
For a 300 watt PV panel, 27~28 panels are needed.
For a 550 watt PV panel, 15~16 panels are needed.
For 700watt PV panels, 11~12 panels are needed.
2. Impact of peak sunlight hours on the monthly electricity generated by solar panels
Peak sunlight hours vary from region to region depending on the geographical location. Some regions have only 3 hours of peak sunlight, while others have up to 6 hours.
For example, assuming that 400W solar panels are installed to generate 1000KWh of electricity per month, about 28 solar panels are needed for an area with 3 hours of peak sunshine, and about 14 solar panels are needed for an area with 6 hours of peak sunshine. In this comparison, peak sunlight hours do have a significant impact on the number of solar panels needed.
3. How do other factors affect the actual power output of solar panels?
3.1 Temperature
If a solar panel gets too hot, it will cause the performance of the solar panel to deteriorate, affecting its power. Different solar panels have different temperature coefficients and are affected by temperature to different degrees.
Assuming that the temperature coefficient of a solar panel is -0.40 and the efficiency of this solar panel is 18%, then for every 1°C above 25°C, the efficiency of the solar panel will lose 0.40%. Assuming that the ambient temperature at which the solar panel is located reaches 30°C, then its efficiency will drop to 17.64%.
3.2 Accumulation on solar panels
In a low rainfall or humid environment, it is very easy to accumulate dust on the solar panel, which leads to a reduction in light transmission, and the solar panel receives less solar radiation, which will reduce the output power. In winter, the accumulation of snow on the panel will also affect the solar radiation.
Therefore, we can clean them in time by using tools such as water guns and soft brushes. Some large residences or large corporations use robotic cleaning, which is more convenient and efficient.
3.3 Inverter and cable loss
In the whole solar energy system, inverters and cables play an important role. When the current passes through inverters and cables, it may cause certain energy loss, and the degree of loss varies from inverter to inverter. Grid-tied inverters have a conversion efficiency of more than 95% and a loss of about 5%, while hybrid inverter and off-grid inverters have a conversion efficiency of more than 90% and a loss of about 10%. By choosing good quality inverters and cables, the power generation efficiency of solar panels can be improved.
4. Conclusion:
How many solar panels are needed to generate 1000KWh of electricity per month is affected by many factors, so it is not possible to calculate the exact value accurately, and you need to analyse it specifically according to the sunshine time of the area you are located in, the output power of the solar panels, as well as your maintenance situation and installation angle. Based on the above information, I believe you can estimate how many panels you need to generate 1000KWh of electricity per month for your home. Not only 1000KWh, but however many kilowatt hours can be calculated.
