Performance Review: 160-Watt Solar Panel on a 35-Day Cruise
This was our second year using the 160-watt monocrystalline solar panel during a 35-day cruise in the North Channel area of Northern Lake Huron. The boat’s equipment setup and cruising patterns were consistent with last year (refer to prior blog entries for details). Overall, the solar panel's performance this year was comparable to last year, with a few minor differences. Below is a comparison of the 160-watt panel's performance in 2013 and 2014, alongside data from the 140-watt polycrystalline panel used in 2012.
Average Amp-Hours Produced Per Day Under Various Conditions
| Condition | 140W Poly (2012) | 160W Mono (2013) | 160W Mono (2014) |
|---|---|---|---|
| Overall average output/day | 53 Ah | 48 Ah | 48 Ah |
| Sunny days | 69 Ah | 71 Ah | 69 Ah |
| Mostly sunny days | 50 Ah | 50 Ah | 56 Ah |
| Mostly cloudy days | 35 Ah | 37 Ah | 39 Ah |
| Cloudy days | 32 Ah | 28 Ah | 20 Ah |
| At anchor | 62 Ah | 61 Ah | 51 Ah |
| With engine use | 43 Ah | 44 Ah | 45 Ah |
(Note: We experienced more cloudy days at anchor this year.)
Daily Performance Highlights
-
Minimum amp-hours/day:
- 2012: 27 Ah
- 2013: 28 Ah
- 2014: 4 Ah
-
Maximum amp-hours/day:
- 2012: 74 Ah
- 2013: 77 Ah
- 2014: 76 Ah
-
Peak amperage output:
- 2012: 10.5 amps
- 2013: 11.5 amps
- 2014: 11.4 amps
Key Observations
This data provides a general understanding of marine solar panel performance under various conditions. Two primary factors influenced output:
- Sunlight levels: Solar panel performance closely correlates with weather conditions (sunny, partly cloudy, etc.).
- Engine usage: When the engine was running, the alternator charged the batteries, often causing the controller to shut down the solar panel.
Test Boat Configuration
The test boat was equipped with the following:
- Freezer/refrigerator: 5 amps, running 6 hours/day
- LED lighting
- Laptop computer: 4 amps, running 3 hours/day
- Radios: 3 amps, running 8 hours/day
- Instruments and autopilot: Used during sailing and motoring
On sunny or mostly sunny days at anchor, the batteries typically reached full charge by 2 PM, resulting in excess power availability for the remainder of the day.