1 year report on Solar Panel Performance - -

[thomasonw]

About 1 year ago we installed two 245 watt Solar Panels on Viking Star.  Before doing so I tried to get information from others who had panels installed about their performance, but all the 'information' was just gut feels.    Well, I have been tracking our panel's daily production via the Morningstar MPPT controller's data logging capability, and today I sat down to work up a 1 year summary. 

Some background:
  O We installed two 245w panels, mounted largely flat and with no tilting / aiming ability.
  O We are using an MPPT type charge controller
  O We are on a boat and have been in the Pacific Northwest the whole year
  O Our 'Cruise' session is from March 1st to November 1st  (Nov..Feb we come into a dock somewhere)

This last point is rather critical, it means 8 months out of the year we need to generate all electricity ourselves - either by the 270A alternator on the main engine, the Kubota DC Generator, or the Solar Panels.   We only have access to cheap shore power from Nov..Feb (when we can really use it to offset heating costs).

And for results:  looking back over the year the actuals came within 2% of modeled (predicted) output.  During our cruising season (March through the end of October) we produced an average of 124.7Ah/day (12v, Boaters like to talk AH/s, but I really tracked in Watt/hrs), saved 245 hours of run-time on our Kubota DC generator, which results in a raw ROI of 5.5 years.   Figuring in the Federal Tax Credit it drops to 3.9 years.


I have more details here if you want to see them: 

http://mvvikingstar.blogspot.com/2013/06/a-year-with-solar-or-is-it-wait-until.html 

-or-     http://tinyurl.com/ln4sntw


-al-


Viking Star
45' Monk Sr. / McQueen
mvVikingStar.blogspot.com