Question - I am from Uttar Pradesh and belongs to a small family, I already have a 250 watt solar panel. I want to run only fan, light and fridge on the solar system for that please suggest me the best battery who give power backup solution according to 250 watt solar panels.
Ans. - To determine the size of the battery you need to run your appliances, you'll need to consider the power requirements of each device, their usage patterns, and the desired backup duration. Let's calculate the battery size based on the information provided.
Fans: Since you have two fans, we'll assume each fan consumes around 50 watts (a common value for ceiling fans).
Lights: The power consumption of lights can vary depending on the type and brightness. Let's assume each light bulb consumes around 10 watts (LED bulbs are generally more energy-efficient).
Fridge: You mentioned a fridge, but we'll need additional information to estimate its power consumption accurately. Fridges can vary significantly in power usage, so you'll need to check the fridge's label or user manual for the power rating in watts. Once you have that information, you can substitute it in the calculations below. To this example, we'll assume the fridge consumes 100 watts.
Now, let's calculate the total power consumption per hour:
Total power consumption per hour = (2 fans × 50 watts/fan) + (2 lights × 10 watts/light) + 1 fridge × 100 watts
Total power consumption per hour = 100 watts + 20 watts + 100 watts
Total power consumption per hour = 220 watts
Since you have a 250-watt solar panel, we'll assume it generates 250 watts of power under optimal conditions. However, keep in mind that solar panel output can vary depending on factors such as sunlight intensity, angle, and weather conditions.
To determine the battery size, you'll need to consider the backup duration time of about 5 to 6 hours during power cut.
Battery size (in watt-hours) = Total power consumption per hour × Backup duration (Assuming a backup duration of 5 hours)
Battery size = 220 watts × 5 hours
Battery size = 1100 watt-hours (or 1.1 kilowatt-hours, kWh)
Therefore, to run your appliances for 5 hours during power cut, you would need a battery with a capacity of approximately 1100 watt-hours or 1.1 kilowatt-hours.
Note - Keep in mind that this calculation serves as a rough estimate, and actual power consumption may vary based on factors like the specific devices' efficiency and usage patterns. Additionally, it's important to consider battery efficiency, system losses, and the depth of discharge (how much of the battery's capacity can be used) when designing a solar power system.