sunny boy inverter?

[solarix]

Canadian Solar is a real good brand too. Done lots of them.... (they don't skip-wire though). Actually, solar PV panels are pretty much of a commodity now. They are all good. There are a lot of brands I've never heard of that I question whether the company will be around long, but they all use the same automated assembly equipment and good quality is not hard to achieve. Just shop dollars/watt between the Tier 1 manufacturers and move on to choosing the inverter brand which is where quality and durability is an issue. The inverter people would like to match the 50 year life of a PV panel and often even offer the 25 year warranty - but getting 10 to 15 years out of an inverter is about the best you can do (despite what the microinverter people claim).

[mudhole]

alright, the panels, inverter, installation materials should be here friday, my question is , my corrugated metal roof over the porch is only a 9 degree angle, i estimate i need a minimum of 20 degrees, since our lattitude is 34, my plan is to use 4x4 treated lattice structure to increase the pitch of the entire area and then attach the track to it. most of my electrical bill is summer with AC and pool pump, from what i read you can minus 15 degrees from the lattitude for summer angle? maybe i could build something i could articulate up 15 degrees for later in the year.

[Ampster]

alright, the panels, inverter, installation materials should be here friday, my question is , my corrugated metal roof over the porch is only a 9 degree angle, i estimate i need a minimum of 20 degrees, since our lattitude is 34, my plan is to use 4x4 treated lattice structure to increase the pitch of the entire area and then attach the track to it. most of my electrical bill is summer with AC and pool pump, from what i read you can minus 15 degrees from the lattitude for summer angle? maybe i could build something i could articulate up 15 degrees for later in the year.

Perhaps I don't understand your idea correctly, but why bother with the lattice. It is not structural and I think it would be less expensive to just put the panels at an angle with rack mounting materials. I will reread the thread to refresh my memory of your plan.

[SunEagle]

alright, the panels, inverter, installation materials should be here friday, my question is , my corrugated metal roof over the porch is only a 9 degree angle, i estimate i need a minimum of 20 degrees, since our lattitude is 34, my plan is to use 4x4 treated lattice structure to increase the pitch of the entire area and then attach the track to it. most of my electrical bill is summer with AC and pool pump, from what i read you can minus 15 degrees from the lattitude for summer angle? maybe i could build something i could articulate up 15 degrees for later in the year.

Adding that lattice structure may get you a few more kWh of production during the Winter but not very much during the Summer. If you want to add to the cost and complexity of your system that is your decision but if it were my money I would just stay with that 9 degree angle.

[mudhole]

how much percentage do you think i would lose leaving it at 9 degrees as opposed to going 20?, my plan is to raise each row a little over a foot, and run the track still, foot of panel at the base of roof, and the top of panel raised a little more than a foot, then running the track along the entire length of 6 panels, do 3 rows of this...

[J.P.M.]

the only other inverter that might be economical is the delta 6000w hybrid, it says it can be run without batteries, but if calamity hits, i could add batteries to it. does anybody have experience with the Delta product?

1.) First off, find out if you need a permit. We're all still in the dark about that. Both permitting and POCO requirements will have a bearing on whether or to what extent rapid shutdown and so the inverter requirements will be required.
2.) Then, since what you want is a grid tie system, find out what's required from your POCO in terms of rapid shutdown requirements. If they do, the usual way to meet that req. is with optimizers.
3.) Then, find out if that Delta product meets all the requirements the AHJ and the POCO will impose on any proposed/considered design or equipment choices.

As for changing the tilt angle, aside from the idea that the 9 deg. tilt angle will probably get fouled more quickly than the 20 deg. angle but may also perhaps need to be less robust for what may be lower design loads from wind - which, if you don't know or haven't considered yet, may be a requirement of you AHJ. in any case, there's nothing sacred about a 20 deg. tilt angle as in "latitude -15 degrees - that's a first cut go by, not gospel. If you're going to change tilt angle anyway, one thing to consider is to go with a tilt angle that results in either the greatest annual electric bill reduction or greatest annual output. Depending on how you are charged for electricity, the two angles are usually not the same, but depending loosely on array azimuth, the max. annual output will probably be at an array tilt of something like you latitude minus a couple degrees or so.

Run PVWatts at your planned array azimuth for 9 deg., 20 degrees and 34 degrees, or any tilt angle(s) ( or azimuths ) of your choice and use (the increased cost of the added structural work)/(the estimated annual bill reduction enabled by the greater tilt(s)) as a SWAG to see how long it will take to recoup the added cost in structural mat./labor from the greater savings - whatever you estimate the savings to be.

If most of your electrical loads are in summer, the increased annual savings (electric bill reduction) from a 20 deg. tilt vs. a 9 deg. tilt may be quite small. Just keep in mind that a 9 deg. tilt will need a bit more frequent cleaning which, to my experience only, mostly amounts to a decent hosing down ~ 1X/month or so if it doesn't rain.

[SunEagle]

how much percentage do you think i would lose leaving it at 9 degrees as opposed to going 20?, my plan is to raise each row a little over a foot, and run the track still, foot of panel at the base of roof, and the top of panel raised a little more than a foot, then running the track along the entire length of 6 panels, do 3 rows of this...

I would run the calculations thru PVWatts at both angles. They may have more dirt depreciation at the lower angle but again their estimated losses will be better then what I can provide.

[mudhole]

1.) First off, find out if you need a permit. We're all still in the dark about that. Both permitting and POCO requirements will have a bearing on whether or to what extent rapid shutdown and so the inverter requirements will be required.
2.) Then, since what you want is a grid tie system, find out what's required from your POCO in terms of rapid shutdown requirements. If they do, the usual way to meet that req. is with optimizers.
3.) Then, find out if that Delta product meets all the requirements the AHJ and the POCO will impose on any proposed/considered design or equipment choices.

As for changing the tilt angle, aside from the idea that the 9 deg. tilt angle will probably get fouled more quickly than the 20 deg. angle but may also perhaps need to be less robust for what may be lower design loads from wind - which, if you don't know or haven't considered yet, may be a requirement of you AHJ. in any case, there's nothing sacred about a 20 deg. tilt angle as in "latitude -15 degrees - that's a first cut go by, not gospel. If you're going to change tilt angle anyway, one thing to consider is to go with a tilt angle that results in either the greatest annual electric bill reduction or greatest annual output. Depending on how you are charged for electricity, the two angles are usually not the same, but depending loosely on array azimuth, the max. annual output will probably be at an array tilt of something like you latitude minus a couple degrees or so.

Run PVWatts at your planned array azimuth for 9 deg., 20 degrees and 34 degrees, or any tilt angle(s) ( or azimuths ) of your choice and use (the increased cost of the added structural work)/(the estimated annual bill reduction enabled by the greater tilt(s)) as a SWAG to see how long it will take to recoup the added cost in structural mat./labor from the greater savings - whatever you estimate the savings to be.

If most of your electrical loads are in summer, the increased annual savings (electric bill reduction) from a 20 deg. tilt vs. a 9 deg. tilt may be quite small. Just keep in mind that a 9 deg. tilt will need a bit more frequent cleaning which, to my experience only, mostly amounts to a decent hosing down ~ 1X/month or so if it doesn't rain.

hey there jpm, i purchased the sunny boy 5.0 -41 inverter, there is an electrical permit needed and i have filled out and am waiting on them to call me in for the money (since the office is shut down), it does not need rapid shut down from everything i can tell, UNLESS NEC codes(this is all the codes in are area are based on) call for it if installed on a porch roof, however it does need a visible air gap disconnect at the inverter per the power company.

[Ampster]

...........however it does need a visible air gap disconnect at the inverter per the power company.

All that means is one of those switch boxes with a handle instead of a circuit breaker. You probably have that on your bill of materials list.

[mudhole]

I would run the calculations thru PVWatts at both angles. They may have more dirt depreciation at the lower angle but again their estimated losses will be better then what I can provide.

what a great site!!!,if i leave at 9%, i lose 4% yearly, however my summer months have a higher kw output , weird, i wouldnt have thought that 10 degrees compared to 20 would be greater output.

[SunEagle]

what a great site!!!,if i leave at 9%, i lose 4% yearly, however my summer months have a higher kw output , weird, i wouldnt have thought that 10 degrees compared to 20 would be greater output.

During the Summer the sun almost works better with near flat panels. It is during the Winter that the angle of the panels work better at the Latitude the array is sitting on.

[J.P.M.]

It is during the Winter that the angle of the panels work better at the Latitude the array is sitting on.

Better than close to horizontal maybe, but the above statement may be misinterpreted as saying the optimum winter tilt is at latitude. It usually is not, at least outside of the tropics.

Tilt at latitude or close to it is often the best for total annual array output.
For mid and higher latitudes, for the same array, tilt at latitude will indeed give greater winter collection than close(r) to a horizontal tilt angle.
However, tilts greater than latitude usually produce more output in the winter than tilts at latitude.

To say that the greatest (better ?) winter collection is when the tilt angle of an array is at latitude is usually not true or correct for most applications. That optimum tilt (to maximize winter production) is usually closer to latitude + 15 degrees or so, or maybe a bit more, particularly for mid to high latitudes above maybe 30 deg. or so.

[SunEagle]

Better than close to horizontal maybe, but the above statement may be misinterpreted as saying the optimum winter tilt is at latitude. It usually is not, at least outside of the tropics.

Tilt at latitude or close to it is often the best for total annual array output.
For mid and higher latitudes, for the same array, tilt at latitude will indeed give greater winter collection than close(r) to a horizontal tilt angle.
However, tilts greater than latitude usually produce more output in the winter than tilts at latitude.

To say that the greatest (better ?) winter collection is when the tilt angle of an array is at latitude is usually not true or correct for most applications. That optimum tilt (to maximize winter production) is usually closer to latitude + 15 degrees or so, or maybe a bit more, particularly for mid to high latitudes above maybe 30 deg. or so.

Good points. I stand corrected. Thanks

[J.P.M.]

Good points. I stand corrected. Thanks

You're welcome.

[solarix]

Go to solarpaneltilt.com for a thorough treatment of solar PV panel tilt angles....