Performance of Our 160 Watt Marine Solar Panel - Year Two

This was the second year we used the 160 Watt solar panel on a 35 day cruise in the North Channel area of Northern Lake Huron.  The boat equipment and cruising pattern was essentially the same as last year (See prior blog entries).  The solar panel performance was comparable to last year with a few minor exceptions.  The data comparing the performance of the 160 Watt panel during 2013 and 2014  and the 140 Watt panel in 2012 is displayed below.

Average amp hours per day produced under various conditions:

                                                       140 Watt, poly    160 Watt, mono    160 Watt, mono
                                                                2012                        2013                       2014

Overall average output per day        53 amp hours       48 amp hours          48 amp hours

Sunny days                                                 69                        71                         69
Mostly sunny days                                       50                       50                         56 
Mostly cloudy days                                      35                        37                        39
Cloudy days                                                 32                        28                        20
                    
Avg. Output on days at anchor                     62                        61                       51
Avg. Output when engine was used             43                        44                       45
 (We had more cloudy days at anchor this year)

 Min amp hrs for a day                                   27                        28                        4
 Max amp hrs for a day                                  74                        77                      76

Max amps output                                      10.5 amps            11.5 amps           11.4 amps

This data is intended to provide a general idea of what to expect from the marine solar panels under various conditions.  The two primary variables are the amount of sunshine and the running of the engine (the alternator charges the batteries so the controller shuts the panels down). 

The test boat was running a freezer/refrigerator drawing 5 amps running 6 hours a day, LED lighting, laptop computer drawing 4 amps running 3 hours a day, radios drawing 3 amps running 8 hours a day, and instruments and autopilot when under sail and power.  When at anchor on a sunny to mostly sunny day our batteries were at full charge by 2 PM so we usually had excess power.