When you calculate the power output from your solar system or design a new solar system to offset your power consumption needs, there are several things to consider.
First and foremost, you should understand that the real-world power output from your solar system can vary significantly from the projected numbers, mainly because of several environmental factors. Also, the actual installation can be preceded by a series of steps to improve your home’s energy efficiency. These steps will substantially reduce your power consumption and, therefore, allow you to installer a few solar panels to meet your power needs. You save on both monthly power bills as well as your investment in the solar power system.
Factors That Affect Power Output From Your Solar Panels
Some of these factors are environmental, and others are technological.
- Production Efficiency
All solar panels come with power generation efficiency ratings. The best-in-class PV cells have ratings close to 20% or even above. The higher the efficiency ratings, the more power your solar panels generate under the same amount of sunlight.
The location of your house has a significant impact on your solar system’s power output. If you’re located in a sunny region like Texas or California, your roof receives over 5 hours of direct sunlight. In contrast, Connecticut homes receive roughly 3 hours of direct sunlight. So, the same solar panel produces less power in Connecticut than what it would do in California.
- Quality and Reliability
Solar panels also come with a wattage specification. Generally, higher wattage translates to higher power output. However, the manufacturing quality significantly impacts how that wattage plays out in the real world. So, always go for trusted and established brands.
Calculating Power Output from Solar Panels
For the sake of our calculation, let’s consider the example of a 375W solar panel. As mentioned before, CT receives roughly 3 hours of direct sunlight.
Daily Power Output from a 375W Solar Panel = Wattage x Hours = 375 x 3 = 1,125 Wh = 1.125 kWh (1 kWh = 1,000 Wh)
When you multiply this number by 365, you get the total power output from a single 375W solar panel over the course of a year, which comes to 421.875 kWh.
So, if you have 10 such solar panels, you can generate about 4,218.75 kWh of power from them annually.
Other Things to Consider
Although the above calculations should give you a general idea of the power output from solar panels, the actual power output will be significantly more, because it will also depend on the production ratio.
If a solar panel has a production ratio of 1.2, it means that the above number, i.e., 421.875 kWh gets multiplied by 1.2, giving us 506.25 kWh.
Likewise, a production ratio of 1.3 means that the actual power output would be 548.438 kWh.
Also, remember that we only took into account the peak sunlight hours. Most solar panels are designed to produce power even under limited light conditions. So, their daily power output would be more, as they churn out energy even during relatively low-light conditions.