LFP backed whole house solar

[Iowa Dave]

The second and slightly more morbid plan might be to put the very best asphalt shingles on and then put the solar on them. Depending on one’s age and future plans it might work out. We have all metal roofs on the house and on the garages but still went with a ground mounted unit for the optimal angle and east west orientation. Also, the snow can be cleaned off without a ladder. The angle is 30 degrees and the orientation is exactly 180 degrees. 26 panels 390 watts each. About 10 feet by 40 feet.
Iowa Dave

[John in Santa Cruz]

what is this 'snow' stuff you speak of?

while we *could* put the panels in the field behind our house, there's an awful lot of tall trees around there, the roof is really the best place, and we have over 3000 sq ft of usable rooftop... we just did a new roof using the thickest grade of premium asphalt shingles, so we're good for 20-30 years.

the two tall trees crossed out in red have already been taken out. they were both over 60 feet tall, so cast long shadows... magnetic north is straight up.

[Iowa Dave]

When we had the preliminary measurements taken, one guy remarked two tall trees to the west might cast a shadow on the panels. It turns out that it’s pretty late In the day and only for a couple months that the shadow gets to the edge of the panels. And by that time “ the photons are in the barn.”

I am thinking about putting 3 raised bed “garden enclosures where the runoff would help the watering on the sunny south edge.The panel edges are about 36 inches off the ground so low growers like strawberries, rhubarb and some low growing vegetables would work. Waiting for the price of lumber to come down, I have enough to build at least one and maybe two. But I have camping to do too.
Iowa Dave

[Mike Lewis]

Originally Posted by splitting_lanes

My panels have been on the roof for ten years and the only cleaning they’ve ever had was from rain. The power just doesn’t drop enough to justify the water usage when we are nearly always in drought conditions.

I did the roof, then had the panels installed.

I remember cleaning the panels on my trailer once and got a 30% boost in charge rate. I'd think all solar panels would get dirty over time.

Years ago I remember reading an article about former Maryland congressman Roscoe Bartlett. He had rooftop solar panels when he lived in Maryland, but when he moved to West Virginia after his political career was over he made a frame to mount them near the ground. He did this so he could access them, but I forgot the reason why. I presume it was for cleaning.

[Brian B-P]

Originally Posted by Mike Lewis

I remember cleaning the panels on my trailer once and got a 30% boost in charge rate. I'd think all solar panels would get dirty over time.

It does depend how they're mounted. The panels on the trailer are horizontal, right?

[splitting_lanes]

Originally Posted by Mike Lewis

I remember cleaning the panels on my trailer once and got a 30% boost in charge rate. I'd think all solar panels would get dirty over time.

Years ago I remember reading an article about former Maryland congressman Roscoe Bartlett. He had rooftop solar panels when he lived in Maryland, but when he moved to West Virginia after his political career was over he made a frame to mount them near the ground. He did this so he could access them, but I forgot the reason why. I presume it was for cleaning.

I can view production data over the life of the system and can see a boost in production after a good rainstorm, or a sag after one of our infamous California fires leaves ash everywhere.

I think I have the system set to be publicly accessible, so you can examine initial production and compare to more recent production: https://enlighten.enphaseenergy.com/...n/graph/months

I think that the panels on a trailer get subject to a lot more dust and residue that can stick to them and impede output than the stationary panels on the roof of a house. That’s all I can think of that would account for a 30% boost from cleaning.

Maybe this spring I’ll get the panels clean, I really only expect maybe 7-8% improvement though. But I’ll have to do it before I know.

[outwiththedogs]

We occasionally put the sprayer on the hose and rinse the solar panels. Not the same as a good cleaning but we have not really noticed a huge change with dusty/clean ones. Water saving is critical here as the state is in drought.

For snow, here in CO it tends to melt off pretty quickly with the sun, even when it is below freezing. I have gotten a big splat of snow on my head a few times on entering the garage and have learned to check the snow overhang and not slam the door!
Catherine

[Mike Lewis]

The panels on my trailer are mounted horizontally. They also get blasted by a 60 MPH wind whenever I'm towing. So my experience is only somewhat analogous to that of a homeowner with panels on the roof.

Still, they get dirty. After all, vertical windows get dirty. It may not be as big a problem as RV-mounted panels, but sooner or later you'd need to clean them. Where you live probably has a lot to do with it as some places are dirtier than others. And this doesn't address having to maintain / repair the roof.

[Brian B-P]

Originally Posted by splitting_lanes

I think I have the system set to be publicly accessible, so you can examine initial production and compare to more recent production: https://enlighten.enphaseenergy.com/...n/graph/months

Your data may be visible to all logged-in users, but to see anything at all, a user has to create an account and log in. Since I don't have one of these systems, I haven't created an account, but it looks like anyone could.

[splitting_lanes]

Originally Posted by Brian B-P

Your data may be visible to all logged-in users, but to see anything at all, a user has to create an account and log in. Since I don't have one of these systems, I haven't created an account, but it looks like anyone could.

Thanks for your feedback! I looked up how to share the public view, here it is:

https://enlighten.enphaseenergy.com/...ems/DeYZ215018

You don’t have access to all the detailed reporting, so it’s probably not easy to see that power generation hasn’t dropped much since installation - the last time the panels were really’clean’.

[Brian B-P]

Originally Posted by splitting_lanes

Thanks for your feedback! I looked up how to share the public view, here it is:

https://enlighten.enphaseenergy.com/...ems/DeYZ215018

Excellent Thanks

A tip for anyone using this: pick a date on the calendar tab first - data for that selected date are then displayed on the other tabs; it starts with today by default.

Originally Posted by splitting_lanes

You don’t have access to all the detailed reporting, so it’s probably not easy to see that power generation hasn’t dropped much since installation - the last time the panels were really’clean’.

20 months of data are available; not much of the ten years, but enough to suggest a trend (of not much longer-term change compared to the seasonal variation). Although there's no trend graph, and an individual day must be selected to get numeric data for that day, the calendar view shows the trend as colour shading and it's easy to pick example days.

[Edroy]

I'm curious to know more about your mini-split setup, manufacturer and distributor if you don't mind sharing. We are off grid in north central Washington and especially interested in some AC capability in late summer.

[Upfisk]

Originally Posted by Edroy

I'm curious to know more about your mini-split setup, manufacturer and distributor if you don't mind sharing. We are off grid in north central Washington and especially interested in some AC capability in late summer.

Our mini splits are a Japanese make. I don't even think this specific model is available anymore. We have 2 mini splits running off 1 rooftop compressor. They are a 240 V unit and our inverter is a dual 120/240 V system. When 1 mini split is running it is using close to 1200 watts, according to our voltage/watts/ charging/ hour meter. We have 1 mini split in the living room and 1 in our bedroom. The bedroom one gets used 1-2 times a year when it is overcast and the night temps do not drop to the low 70s or high 60s. Our max sun charging is around 1200-1500 watts for about 1 hour so the mini split is a net loss on our system. Most of the day's charging is in the range of 600-1000 watts. We can angle our panels for summer or winter, but they are fixed south and do not track.