Solar Wiring Tips

Wiring Solar Panels: Series vs. Parallel and Hybrid Setups

Let’s get down to the nitty-gritty of solar energy capture. The two primary wiring configurations, series and parallel, each have distinct advantages. However, you may want to consider a combination of both to maximise power output while minimising losses.

Before we go any further, if you’re wiring different size panels together, things get more complicated and you may want to skip to the table at end of this article for information before you start. Using the same rated panels, or close, will give you a much more efficient system.

Tip: Always check you Power Station’s solar input (MPPT) specifications so you can keep within their limits and prevent any damage to the unit.

In this article, we’ll cover:

The differences between series and parallel wiring

Why combining both can be beneficial

The advantages of higher voltage over higher amperage

Series vs. Parallel Wiring: Key Differences

1. Series Wiring

When solar panels are wired in series, the positive (+) terminal of one panel connects to the negative (-) terminal of the next.

Key Characteristics:

Voltage adds up - e.g. two 12V panels in series = 24V.
Current (amperage) stays the same as a single panel.

Advantages:

Less voltage drop and power loss occurs over long wire runs.

Thinner wiring can be used.
Better for power stations with higher input voltage capability.

Effective in lower sunlight conditions.

Disadvantages:

Partial shade will reduce the current flow through the whole array, lowering the efficiency.

2. Parallel Wiring

When panels are wired in parallel, all positive terminals (+) connect together, and all negative terminals (-) connect together. The result is that current (amperage) adds up (e.g., two 5A panels in parallel = 10A) and voltage stays the same as a single panel.

Key Characteristics:

Current or amperage adds up – e.g. two 8A panels in parallel = 16A

Voltage stays the same as a singe panel.

Advantages:

Suits situations with partial shading concerns as shading one panel will not drag down the whole system. 

Disadvantages:

Parallel setup means you use more cable to join the panels.

More prone to power losses over long cable runs.

Requires thicker cable to be more effective (you can look up AWG charts to see what suits your amperage).

Combining Series and Parallel: The Best of Both Worlds

 

Many solar arrays use a series-parallel hybrid approach, where multiple series strings are connected in parallel.

Example Setup:
4 x 18V, 5A panels
Wired as 2S2P (two pairs in series and those pairs wired in parallel)
Each series pair: 18V + 18V = 36V, 5A
Two pairs in parallel totals 36V, 10A system.

Advantages of Hybrid Wiring:
Higher voltages can be achieved, while keeping the Amperage within the power stations MPPT limitations.
More flexible shading tolerance (one shaded panel affects only its series string, not the whole array)
More panels can be utilised which means faster solar charging.

Why Higher Voltage is Better Than Higher Amperage

1. Lower Energy Losses
Power loss in wires is proportional to the square of the current (I²R)
Higher voltage = lower current for the same power (P = V × I).
For example: A 1000W array at 12V draws 83A, while at 48V, it draws only 21A, resulting in 16 times less resistive loss! 

2. Thinner Wiring
High-current systems require thicker, copper cables to minimise losses. Higher voltage setups allow for smaller gauge wires, reducing material costs.

3. Better Compatibility with MPPT Charge Controllers
Sherpa Power Stations have built-in MPPT (Maximum Power Point Tracking) controllers. These work best with higher input voltages, improving efficiency, especially in low-light conditions.

4. Longer Distance Runs Without Voltage Drop
Higher voltage systems can transmit power over longer distances without significant losses, making them ideal for large solar farms or remote installations.

For most medium-to-large installations, favouring higher voltage with series or hybrid wiring is the smarter choice - reducing losses, saving on wiring costs, and improving overall efficiency.

Wiring Scenarios Table

	Power (W)	Voltage (Voc)	Current (A)	Two in Series	Two in Parallel
Panel 1	120W	18.2V	6.6A	240W, 36.4, 6.6A	240W, 18.2V, 13.2A
Panel 2	250W	34.2V	7.3A	500W, 68.4V, 7.3A	500W, 34.2V, 14.6A
Panel 3	400W	30.7V	13A	800W, 61.4V, 13A	800W, 30.7V, 26A
Three in Series	548W	83.1V	6.6A
Three in Parallel	489W	18.2V	26.9A

Table demonstrating the outcomes of wiring similar panels together (across) vs. mixed panel specifications (down). The red highlights where the system performance is limited.

We hope this has cleared some things up for you as you prepare for the summer. 

Go steady,

Sherpa Power