Yash
Our 5 kW On-grid solar power system generated 616 kWh of energy and saved Rs. 4,312 in September 2023.
The On-grid solar power system is connected to the grid through a net meter.
The net meter allows the bi-directional energy flow between the solar power system and the grid.
The extrasolar units generated in the day are fed to the grid through the net meter.
Whereas the grid can also be imported in the night when solar is not working.
The net meter gives the net unit consumption.
For example, 100 units are imported from the grid and 30 units are exported to the grid through the net meter.
The net consumption would be the difference between the two that is:
Import – Export,
100 – 30 = 70 units.
The consumer would be billed for these 70 units.
So, the On-grid solar power system saves you money by lowering the electricity bill.
The On-Grid system is preferred where the electricity prices are high like in the metropolitan cities.
Factors affecting the performance of solar power systems:
Solar panels are the very component of any solar power system.
They absorb the sunlight and convert it into electricity.
However, the source of their energy which is Sunlight intensity is not constant throughout.
It varies from sunrise to sunset, with the change in the seasons, and changes with the latitude of your location.
1. Daily variations in the sunlight intensity
The sunlight intensity is the minimum when the sun rises in the morning.
Gradually, it starts increasing and reaches the maximum in the noon.
Thereafter it again starts decreasing and reaches the minimum when the sun is setting.
The sunlight intensity with time can be observed as follows:
2. Seasonal variations
The next factor that affects the sunlight intensity is the change in the season.
In North India we see four main seasons:
- Summer
- Winter
- Monsoon
- Autumn
And in each season, we feel different values of the sunlight intensity.
In summer when the sun is nearer to the earth, we feel sunlight more intense compared to that in winter when the sun is relatively far.
3. Variation in the Peak Sun Hours due to latitude
Another factor that affects the Peak Sun hours of any region is its location with respect to the equator which is its latitude.
If the location is nearer to the equator, it will receive more sunlight than a region that is far away from the equator.
The overall sunlight intensity in any location is the result of the above-mentioned natural factors. However, there are other factors that affect the sunlight intensity falling on the solar panels such as:
- Shade from the nearby things
- Dirt accumulation on the panel surface
These factors are in our control to a great extent.
Therefore, we will not discuss them at this time.
Performance of 5 kW On-grid Solar in September 2023
Now, coming to the main point.
Our 5-kW solar power system generated 616 units in September 2023.
This system is installed in Delhi/NCR region with a latitude of 28 degrees.
This region receives a fairly good amount of Peak Sun Hours an average of over 5 per day.
Also, September is a month when the monsoon season starts receding from North India.
We can still see clouds in the sky and occasional rains in the first half of the month.
One can still feel the moisture in the air.
This water content obstructs the sunlight from falling on the solar panel’s surface, affecting its performance.
The September month was a kind of mix-bag for us.
We saw clouds and rain on one side while the clear sky and sunny days in the later part of the month.
Let us look at the performance chart of the 5-kW On-grid system:
There are 30 bars representing the 30 days of the September month.
Each bar represents the energy produced on a particular day of the month.
The height of the bars shows the value of the energy generated.
You will notice a large variation in the height of the bars with some bars above 25 kWh while others are even struggling to rise above 15 kWh levels..
And the one is even below the 10-kWh level.
Why there is such a large variation in energy production?
The reason for the low production is the clouds and the rain.
The energy generation above 25 kWh indicates a clear sky and a sunny day.
“September showed us all the shades of nature”
Let me show the information in tabular form:
Date Energy Date Energy Date Energy
Minimum Performance
On September 10, 2023, the energy production was merely 7.7 kWh or 7.7 units.
This day was full of clouds and rain from morning to evening.
However, we saw some streaks of sun rays in between but otherwise, it was cloudy and rainy.
The clouds in the sky and the water content in the air prevent the sunlight from falling directly over the solar panels.
However, our efficient half-cut monocrystalline solar panels absorbed the diffused sunlight in the atmosphere and generated 7.7 units on that day.
Maximum Performance
While on another hand, there was a day when the same solar panels produced 26.8 units of energy on September 28, 2023.
This day was clear and sunny.
The solar panels worked to their full potential and absorbed the maximum energy they could.
You will also notice that the pattern of 20+ kWh energy production started on September 25 and it broke on September 29.
The reason for this was the grid breakdown, not the cloudy weather.
The grid-tied solar inverter needs an input voltage for its functioning.
This input voltage is supplied through the grid.
When the grid shuts down, the solar inverter does not receive the input voltage working for its functioning.
Hence the whole solar power system stops working.
There was a grid shut down for 2 hours on this day.
One lesson to be learned: The On-Grid system is beneficial where the grid supply is continuous.
Total Energy produced in the September month
When I add each day’s energy production from September 1 to September 30.
The system generated 616 kWh or 616 units.
Giving me a daily average of 20.5 units (616 units/30 days).
This is fairly a good performance for the 5-kW solar power system in September. Where we saw the clouds and rain in the first half of the month.
Money saved by the 5-kW On-grid solar in September
1 unit of grid electricity cost us Rs. 7.
Our system generated 616 kWh of energy in September.
The savings of the month can be calculated as:
Savings (Rs.) = Cost of 1 unit x Solar units generated
= Rs. 7/unit x 616 units
= Rs. 4,312
Conclusion
- The first half of September month in Delhi/NCR was filled with clouds and rain. And we saw clear sunny days in the later-half of the month.
- The clouds and the water content in the air affected the performance of the solar panels.
- The efficient monocrystalline solar panels perform better than polycrystalline ones in low sunlight conditions.
- The shut-down in the grid supply affected the functionality of the solar inverter.
- The system generated a total of 616 units and saved us Rs. 4,312 in the September month.
