Calculating Power with Solar Cells: Series vs. Parallel

• brycenrg
In summary: To get around those losses, you can use a transformer for the DC/DC conversion, but that is also costly and heavy. So the best solution is to use higher voltage DC from the panels and minimize the current. A transformer can then be used for the AC conversion.In summary, solar panels with a higher voltage are preferred over ones with higher current. This is because higher voltage results in lower power dissipation and switching losses, making it a more efficient option for converting DC to AC power. Placing solar cells in series will increase the voltage, while placing them in parallel will increase the current. However, the product of voltage and current remains the same in both cases. Wh and W represent the same unit, with Wh being a
brycenrg
So I am trying to figure out how much Wh I would have with these solar cells I have. Each solar cell is rated to have 2.8w. Does this mean if I have 40 of them I would have 112 wh? I am going to be putting the solar cells in series. Does this affect the power? I know adding in series is good because it boost your voltage but.. I am not sure if that affects your power. If it does then, How do i figure out what my power would be?

Power is energy/time. Here it can be simply added up. So with 40 x 2.8 W you have 112 W, not 112 wh .
112 W is 112 Wh per hour. Wh is a practical unit for energy. 1 Wh = 3600 Joule.

Power is simply Voltage x Current. Placing the 40 cells in series you get 40 times the voltage from one cell at the same current.
Placing them parallel you get 40 times the current of one cell at the voltage of one cell for the whole lot.
Product Voltage x Current is same in both cases.

berkeman
BvU said:
Power is energy/time. Here it can be simply added up. So with 40 x 2.8 W you have 112 W, not 112 wh .
112 W is 112 Wh per hour. Wh is a practical unit for energy. 1 Wh = 3600 Joule.

Power is simply Voltage x Current. Placing the 40 cells in series you get 40 times the voltage from one cell at the same current.
Placing them parallel you get 40 times the current of one cell at the voltage of one cell for the whole lot.
Product Voltage x Current is same in both cases.
Thank you, isn't W and Wh the same thing but just Watt over that hour which gives it practical application? Ok so putting them in series or parallel doesn't effect the power. Interesting. Now I'm wondering why people prefer to use series to obtain higher voltage.

brycenrg said:
W and Wh the same thing
Are speed and distance the same thing to you ?
brycenrg said:
Now I'm wondering why people prefer to use parallel to obtain higher voltage
So am I. Any reference ?

BvU said:
Are speed and distance the same thing to you ?
So am I. Any reference ?

Whoops, i mean series. Yeah I'm wondering why its better to make a solar panel with high voltage than high current. People prefer to put in series to get the higher voltage out of the system. Maybe it depends on the item?

Oh sorry, so W = Joule/second , Wh = joule? makes sense now. Wh is total energy given out in one hour

brycenrg said:
so W = Joule/second
Yes. And therefore Ws = Joule, Wh = 3600 Joule
brycenrg said:
People prefer to put in series to get the higher voltage out of the system
Transporting the energy goes at the cost of losses due to resistance. The higher the voltage and the lower the current, the better: the power dissipated in a resistor is I2 R so 10 A at 0.1 ##\Omega## is 10 W loss. With 10 V and 10 A that is 10 %. With 100 V and 1 A you lose only 0.1% of the same 100 W of generated power.

brycenrg and berkeman
brycenrg said:
Whoops, i mean series. Yeah I'm wondering why its better to make a solar panel with high voltage than high current.
In addition to BvU's reply which mainly applies to distance transmission of AC power, even in small installations like solar power panels in a home, you minimize switching FET and diode losses when you have a higher working voltage. Solar panel systems need to convert the DC voltages from the panels to 12V or 120Vrms (or whatever AC Mains voltage your household is using), and the switching losses from the FETs or IGBTs and diodes become higher when the voltages are lower.

Last edited:
brycenrg

1. What is the difference between series and parallel connections for solar cells?

Series connections involve connecting the positive terminal of one solar cell to the negative terminal of another, while parallel connections involve connecting the positive terminals and negative terminals separately. This affects the overall voltage and current output of the solar cells.

2. How does the power output of a solar cell change when connected in series vs. parallel?

The power output of a solar cell connected in series will increase due to the combined voltage of each cell, while the power output of a solar cell connected in parallel will increase due to the combined current of each cell.

3. Can I mix series and parallel connections for my solar cell system?

Yes, it is possible to have a combination of series and parallel connections in a solar cell system. This can be useful for optimizing the power output for different conditions.

4. How do I calculate the overall power output of a solar cell system with series and parallel connections?

To calculate the overall power output, you will need to calculate the power output of each individual solar cell and then add them together. For series connections, you can simply add the voltage of each cell, while for parallel connections, you can add the currents of each cell.

5. Which connection type is better for maximizing power output in a solar cell system?

The best connection type for maximizing power output will depend on the specific conditions and requirements of the system. Generally, series connections are better for systems with low light conditions, while parallel connections are better for systems with high light conditions.

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