--- In [email protected], "Ron Jones" <r...@...> wrote: > > James Cook wrote: > > One of the most important things to remember is to make sure that the > > panel is mounted on an adjustable frame so as to maximise the 'impact' > > of the sun's rays. Some have calculated that laying the panel flat > > reduces the output, which is NEVER that great, by as much as 60%. The > > lumpy water boys and girls are finding this out to there cost as many > > blue sea sailors have bought the very costly stick on, flexible panels > > and are very disappointed. > > <scientist hat on> > Could probably more than that... > The suns rays are more or less parallel, therefore as the panel is tilted so > less sun hits the panel. If we have the panel at 90deg to the sun then we > get max power, if it's at 0deg (i.e. edge on) then we get zero power - so > just look up sine tables and x 100 to get a %age > http://www.mathnstuff.com/math/spoken/here/2class/330/sincost.htm > Sine 90 is 1 (100%) Sine 0 is 0 (zero) > Panels at, say, 60deg / 45deg / 30deg give results of 86.6% / 71.9% / 50%. > This is theory - note that the panel has a transparent covering - at the > lower angles, it's going to start to act like a mirror and reflect the sun > away, so the lower figures above will be even more worse, than compared to > the high ones - one may find that at 10deg it's all reflection and no > absorption. So flat on top of the boat in the winter is naff all use. > > Easy when you know how. > > Ron Jones > Hi Ron, I have been studying the thread on Solar, as I am considering fitting a panel(s) on my boat. I will probably fix it with a Hi-Fi Speaker ball joint fixing, to enable on to sort the angles out.
It seems that glass faced non-flexible are the most suitable. I am not sure how effective a 130watt x 24-volt panel will be for me, as I am a high user of electricity. (6 x 110amp/hour batteries, wired to give a 24-volt output. I have an inbuilt solar panel controller in my Combi-inverter. However, it will probably keep my fridge/freezer working longer, when I am away for a long weekend. hopefully it will "help" to keep my batteries in better condition, providing I don't forget to top up the water levels! (Often overlooked). The Solar thread has been most informative. ~Allan~ >
