How Much Electricity Can Be Generated Per Day if the Rooftops Are Covered with Photovoltaic Panels?

Yesterday, a reader said that his 11-kilowatt off-grid power station has three air conditioners and water heaters working simultaneously every day for 24 hours without interruption, and he no longer has to worry about the electricity bill. Then, after work, I observed the rooftops of the self-built houses around and found that many of them had photovoltaic panels slanted onto the tiles. (The rooftops in Jiangsu, Zhejiang and Shanghai are all slanted on both sides.)

The sloping roof is covered with photovoltaic panels. I just realized that there are actually many cases of using household solar photovoltaic systems around us.

It's just that electricity charges in our country are cheap and easy to use. Many people think there's no need to go to great lengths to save some money. For some households with high electricity consumption and convenient installation, it may be quite common on their own rooftops. Moreover, nowadays trams are becoming increasingly common. Those who have their own yard roofs may be more inclined to install photovoltaic panels.

So I was a little curious. In the Jiangsu and Zhejiang regions, if all such roofs were fully covered, how many kilowatt-hours of electricity could be generated in a single day during the summer?

In the Jiangsu-Zhejiang-Shanghai region (Jiangsu, Zhejiang and Shanghai), if the roof of a self-built house or villa is covered with photovoltaic panels, the actual power generation depends on several factors, such as the roof area, orientation, Angle, whether there is any obstruction, the type of components and the weather, etc. We can make an estimation based on a common situation:

Assuming the roof area is 100 square meters, approximately 150W of photovoltaic panels can be installed per square meter.

Total installed capacity: 100㎡ × 150W = 15kW

In Jiangsu, Zhejiang and Shanghai regions, the average sunshine duration (effective power generation hours) is generally 3.5 to 4 hours per day (with a median of 3.8 hours).

15 kW×3.8 hours =57 kilowatt-hours per day

So: It can generate approximately 55 to 60 kilowatt-hours (kWh) of electricity in a whole day. For ordinary household users, the electricity used by all household appliances and new energy vehicles at home is more than sufficient.

Of course, when it's rainy or cloudy, do our photovoltaic panels stop generating electricity at all? No, it can still generate electricity on rainy and cloudy days, but relatively speaking, it's 10 to 20% less. In winter, the sun is exposed to the sun for a shorter period of time. If there is continuous rainy and cloudy weather, the power generation may drop below 20 to 30 kilowatt-hours.

If the monthly power generation of the roof is approximately 55 × 30 = 1,650 kilowatt-hours per month

Annual power generation:

approximately 55 × 365 = about 20,000 kilowatt-hours

So, if you are interested in solar energy, have a large household electricity consumption, and own a roof or outdoor space, you can try installing a solar power generation system.