How to Calculate Batteries and Inverters For Your Off-grid Solar Power System?

Solar power has become a popular renewable energy source for home due to the advantages of environment friendly, self-sufficiency, and government policy incentives. More and more homeowners take consideration of installing the off-grid solar system but they might still have some confusions. In this article, we’ll delve into the issue of how many solar panels, solar batteries and inverters do the off-grid solar power system really need. If you are planning to invest the off-grid solar power system for your home, please keep reading.

What are Solar Power System Including?

For off-grid solar power system, there are three major components:

Solar Panel: To generated solar into DC current

Solar Inverter: Turn DC current to AC current that powering most home appliances

Solar Battery: To store exceed power for later use

To learn more about how solar power system working? Click here.

After disclosing how solar power system working, the next things we need to do is calculate the energy needs. This will help us to determine how may solar panels inverters and batteries are needed for home.

 Calculate the total wattage of the load you want to power

Sum up the wattage of each appliances, which can be founded on the nameplates, in kilowatts or watts.

For example, you need a solar power system to power the following loads below,

Television: 80 watts

Laptop: 65 watts

Freezer: 245 watts

Fans: 75 watts

10* LED Light Bulbs: 110 watts

Air conditioning: 1500 watts

Thus,

Total Wattage = 2000 watts

How to Calculate Solar Inverters?

Then, Sizing the solar inverters. Normally, we recommend that the capacity of solar inverter is twice the size of total energy requirements. In this case, where your total electrical load is 2000 watts, you should choose an inverter size of at least 4000watts.

How many Batteries Do you Need for the solar power system?

The next stage in calculating the size of the solar system is to consider how many hours of backup you need.

Suppose you need a eight-hour backup time at night when there is no sunlight. You can use the following formula, to determine the size of the required battery bank. In these case,

Power Consumption

Total Wattage * backup time * 0.6 (Coefficient of the same period) = 2kw*8hrs*0.6= 9.6KWh

Assume solar inverter is 48V

9.6KWh/48V=200Ah

Thus, the battery rate capacity is 48V 200Ah. 4 pieces of 12V 200Ah batteries are needed.

Sum up

To power a load of 2KW using solar with 8 hours backup time at night needs

4KW solar inverter and 4 pieces 12V 200Ah batteries

SVC Power Off-grid Solar Inverter Recommendation

VMH 3KW/5KW/10KW rated capacity available

Pure Sine Wave Output

Compatible with lead-acid/LiFePO4 battery