How Much Solar?
I'm getting a new truck camper and plan on adding a 170 watt solar panel on the roof, which got me to thinking, why not add another 170 watt panel, or two more panels? Is there an advantage to having...
Forum Discussion
From what I have learned about solar, The main benefit of having additional panels is for those days you are not getting full sun or only getting sun for part of the day.
Say you have a day where the morning was cloudy and you were getting zero to minimal output from the panels. Then during the afternoon, you get about 3-4 hours of bright sun giving you near maximum output from your panels. Obviously if you have a third (all equally rated panels) panel vs. two, you are going to recover about 50% more AH's than you would with just the two. So it's a matter of better recoverability in less than ideal conditions.
On good sunny days, you may recover to near full on your batteries and have "overkill" solar. So it's a case of how much recoverability do you want and how much do you hate running the genny. If that aggravates you, add the extra panel. If it's not a big deal to run the genny on cloudy days if you need to, save the hundred and change to spend on something else.
Say you have a day where the morning was cloudy and you were getting zero to minimal output from the panels. Then during the afternoon, you get about 3-4 hours of bright sun giving you near maximum output from your panels. Obviously if you have a third (all equally rated panels) panel vs. two, you are going to recover about 50% more AH's than you would with just the two. So it's a matter of better recoverability in less than ideal conditions.
On good sunny days, you may recover to near full on your batteries and have "overkill" solar. So it's a case of how much recoverability do you want and how much do you hate running the genny. If that aggravates you, add the extra panel. If it's not a big deal to run the genny on cloudy days if you need to, save the hundred and change to spend on something else.
