Solar at its Best
The Ultimate in Solar ? It probably don't get no better than this, I was camped near this guy most the week, and he built this himself. He is a retired mechanical engineer. This unit is compl...
Forum Discussion
A 130w 12v panel has an Isc of approx. 8.2a, which you should get when the panel is aimed right and the sun is high enough, in blue sky.
That contraption in the photo should be pulling approx. 16a for much of the day in sunny conditions if twin 130s, but I agree, they appear to be twin 230w and he must have MPPT for them as well.
It may be helpful to look at an example where we are doing 50-90s but with solar to extend the time between gen recharge times. (We don't have quite enough solar to keep up with usage)
In this case, we have a 490AH bank and one 130w panel tilted at a fixed tilt angle, but in a swivel contraption, so it is a manual tracker of a type. It gets a daily AH haul of 90AH on a sunny day similar to what a 200w array lying flat would get.
I don't know our daily AH usage, it varies from 100-50 depending on all sorts of things, mostly closer to the 100. OK, so the way it went recently, starting with close to full batts on 30 Aug.
Mixed weather so 3 Sep after four days morning 12.1v, did a gen recharge to 90%,
Next was three mostly cloudy days, and 12.1v on 6 Sep. Gen to 90%
Then the sun finally came out for some more summer-like weather and
today 14 Sep hit 12.1v after eight days.
The trouble with this routine of solar assist to stretch out the time between 50-90s is you can spend a week, or who knows how much longer, with the batts riding between 12.3 and 12.5, and this isn't great for sulfation concerns.
-With two 130s we would be mostly gen free but two cloudy days in a row would change that.
-Went most of mid-April to mid-August with only a few gen recharges when we had more solar than now.
-Also we were doing more like 85-97s so the batts were happy to get almost full fairly often.
-To get right full we would have to do the split bank trick to equalize half the bank at a time. No big deal as a monthly chore.
At no time is it safe to have no gen available as a back up where you are in a place that can get cloudy for a couple days in a row, with a normal RV solar outfit of a couple panels on the roof.
Where solar is good, often it is also hot. So you see all these plaintive threads about how to run the air conditioner with no gen and just solar. Not my problem, thank goodness. :)
That contraption in the photo should be pulling approx. 16a for much of the day in sunny conditions if twin 130s, but I agree, they appear to be twin 230w and he must have MPPT for them as well.
It may be helpful to look at an example where we are doing 50-90s but with solar to extend the time between gen recharge times. (We don't have quite enough solar to keep up with usage)
In this case, we have a 490AH bank and one 130w panel tilted at a fixed tilt angle, but in a swivel contraption, so it is a manual tracker of a type. It gets a daily AH haul of 90AH on a sunny day similar to what a 200w array lying flat would get.
I don't know our daily AH usage, it varies from 100-50 depending on all sorts of things, mostly closer to the 100. OK, so the way it went recently, starting with close to full batts on 30 Aug.
Mixed weather so 3 Sep after four days morning 12.1v, did a gen recharge to 90%,
Next was three mostly cloudy days, and 12.1v on 6 Sep. Gen to 90%
Then the sun finally came out for some more summer-like weather and
today 14 Sep hit 12.1v after eight days.
The trouble with this routine of solar assist to stretch out the time between 50-90s is you can spend a week, or who knows how much longer, with the batts riding between 12.3 and 12.5, and this isn't great for sulfation concerns.
-With two 130s we would be mostly gen free but two cloudy days in a row would change that.
-Went most of mid-April to mid-August with only a few gen recharges when we had more solar than now.
-Also we were doing more like 85-97s so the batts were happy to get almost full fairly often.
-To get right full we would have to do the split bank trick to equalize half the bank at a time. No big deal as a monthly chore.
At no time is it safe to have no gen available as a back up where you are in a place that can get cloudy for a couple days in a row, with a normal RV solar outfit of a couple panels on the roof.
Where solar is good, often it is also hot. So you see all these plaintive threads about how to run the air conditioner with no gen and just solar. Not my problem, thank goodness. :)
