Best solar panel angle for east/west to maximize Sunrise to Sunset

[bryhan67]

Looking for some advice on best angle for putting some extra solar panles on my off grid home. I already have a surplus amount of panles. I have 60 panles of 315w each so by 9am my batteries are full. and thats only using 40 panles. I want to take about 12 panles, 6 facing east and 6 facing west. This way I can use less of my battery bank. I am in south west usa zip code 92231. Its very hot and run the Air Conditioner 24/7 so anything to use less battery is great long term. Mostly only concerned for summer time.

My roof is already east / west pitch. I was think on the pint of my roof put the 12 panles back to back. I wonder if 45deg is enough. 45deg A frame is easy to do. Trying to stand them vertical at 90deg would be tough but doable.

Also and idea the power the panles produce with the sun hitting at 45deg?

Again not looking for a daily max power out of the panel. Just get that extra hour or two each day not dipping into my batteries.

45deg vs 90deg what is the difference to extend charging later in day and early in morning. Maybe I will do some test to. Really all about the time of day and still charging vs on battery power.

Every day I watch the clock and crank all the air conditioner to get the house cold usually 8am to 5pm I can run it all. would be nice 7am to 6pm crank it all.

As cheap as solar is im surprised there is not more discussion. I guess this would mostly apply for off grid homes.

 

[Protowrxs]

The best option is the 90 degree angle, but the complexity of east-west tracking is questionable depending on the cost, etc.
I originally replied about the up/down angle, which is most important. I have built an east-west 400w tracker, but haven't activated it yet to test.

 

[bryhan67]

Wonder the actual number difference from 90 to 45deg? its its only 10% then 45deg is ok. Im thinking long term and trying to use as little as battery as possible at .20 cents a watt of solar its no big deal. IF its worth it I might put even more panles just for e/w. The longer I can crank the AC the cooler my house will stay in the night when I turn it all off.

 

[DThames]

You can play with PVwatts to create some off angle calculations and determine at what angle you start seeing a lot less production. The sun is pretty much straight overhead for me this time of the year, at noon. I have panels set about 30-35 degrees from horz and they were getting about 70% of rating at noon. 45 degrees facing west would seem pretty good for afternoon production.....maybe.

 

[bryhan67]

You can play with PVwatts to create some off angle calculations and determine at what angle you start seeing a lot less production. The sun is pretty much straight overhead for me this time of the year, at noon. I have panels set about 30-35 degrees from horz and they were getting about 70% of rating at noon. 45 degrees facing west would seem pretty good for afternoon production.....maybe.

I think I will set up 6 on the house at 45deg maybe even 6 more at almost 90 and see the difference as amps in to the clock and time of day. if its huge difference I will look into it more. There must be a chart somewhere as the sun faces the panel perpendicular then as it moves.

 

[bryhan67]

Looking at one of my controllers data on panles I have totally flat. Noon 2000 watts and 4pm is 1000 watts 5:20pm is 500 watts. Would splitting noon to sunset give you 45deg angle?

Sun also feels a little weaker at sunrise and sun set? Not sure if thats just the temperature doing that.

If I could get 3000 + watts from 6am to 7:30 pm would be huge for me. Maybe need to think about 75-80deg angle.

Sunrise here today is 5:43am
Sunset is 7:51 pm

 

[DThames]

Study of angle and production. Some reading may be required.

 

[Xhumeka]

FWIW, up here on the 45th parallel, I have my panels mounted at about 40 degrees East/West and get FULL power around 3pm this time of year.

I have 8x250W panels, 1KW (4) on the East, 1KW (4) on the West. My Midnight Classic reported peak production of just over 2000 Watts on sunny days.

It actually surprised the heck outta me and I had to upgrade the breaker going into my charge controller. I never expected full power with panels positioned East/West, but there you have it!

East facing side:

 

[Dave (Boog)]

Do a Google search, there are web sites out there that will give you the precise angles to use for your PANELS. based on your Long/LAT.

PVWatts

Estimates the energy production and cost of energy of grid-connected photovoltaic (PV) energy systems throughout the world. It allows homeowners, small building owners, installers and manufacturers to easily develop estimates of the performance of potential PV installations

pvwatts.nrel.gov

 

[Bluedog225]

+100.

The link above is gold. You can use default values and just adjust the angle and see the difference. There is even an hourly production spreadsheet you can download.

Also, the energy in early, early and late, late sun is diminished. Therefore, 90 degrees may not be optimal.

You are on the right track trying to fatten your curve. I have the same plan. Freeze the carp out of the place while the sun shines.

Let us know what you decide.

 

[GLC]

Looking for some advice on best angle for putting some extra solar panles on my off grid home. I already have a surplus amount of panles. I have 60 panles of 315w each so by 9am my batteries are full. and thats only using 40 panles. I want to take about 12 panles, 6 facing east and 6 facing west. This way I can use less of my battery bank. I am in south west usa zip code 92231. Its very hot and run the Air Conditioner 24/7 so anything to use less battery is great long term. Mostly only concerned for summer time.

My roof is already east / west pitch. I was think on the pint of my roof put the 12 panles back to back. I wonder if 45deg is enough. 45deg A frame is easy to do. Trying to stand them vertical at 90deg would be tough but doable.

Also and idea the power the panles produce with the sun hitting at 45deg?

Again not looking for a daily max power out of the panel. Just get that extra hour or two each day not dipping into my batteries.

45deg vs 90deg what is the difference to extend charging later in day and early in morning. Maybe I will do some test to. Really all about the time of day and still charging vs on battery power.

Every day I watch the clock and crank all the air conditioner to get the house cold usually 8am to 5pm I can run it all. would be nice 7am to 6pm crank it all.

As cheap as solar is im surprised there is not more discussion. I guess this would mostly apply for off grid homes.

Looking for some advice on best angle for putting some extra solar panles on my off grid home. I already have a surplus amount of panles. I have 60 panles of 315w each so by 9am my batteries are full. and thats only using 40 panles. I want to take about 12 panles, 6 facing east and 6 facing west. This way I can use less of my battery bank. I am in south west usa zip code 92231. Its very hot and run the Air Conditioner 24/7 so anything to use less battery is great long term. Mostly only concerned for summer time.

My roof is already east / west pitch. I was think on the pint of my roof put the 12 panles back to back. I wonder if 45deg is enough. 45deg A frame is easy to do. Trying to stand them vertical at 90deg would be tough but doable.

Also and idea the power the panles produce with the sun hitting at 45deg?

Again not looking for a daily max power out of the panel. Just get that extra hour or two each day not dipping into my batteries.

45deg vs 90deg what is the difference to extend charging later in day and early in morning. Maybe I will do some test to. Really all about the time of day and still charging vs on battery power.

Every day I watch the clock and crank all the air conditioner to get the house cold usually 8am to 5pm I can run it all. would be nice 7am to 6pm crank it all.

As cheap as solar is im surprised there is not more discussion. I guess this would mostly apply for off grid homes.

Where are you located? I have been doing some tracking on my home for a while. I am located in Ft Worth Texas.

 

[bryhan67]

I am actually near San Felipe Baja California. 30.751119, -114.696263 or

30°45'04.0"N 114°41'46.6"W · Ensenada, Baja California, Mexico

Ensenada, Baja California, Mexico

goo.gl

Did a quick test yesterday with one panel. I was told I could connect neg and pos from the panel. I then put a clamp meter.

Noon with a panel flat perpendicular to the sun was close to 8amp

7pm 4 amps at 80-90 deg

7pm 3.2 amps at 45 deg

630 pm 6 amp 80-90 deg

Noon with a panel flat perpendicular to the sun was close to 8amp

I think around 70 deg is what I will shoot for. Mostly because of mounting . Wanted to do 45 but its a big difference to 90deg. Not worried about total KWH just more watts later in the day. I think 6 panles might not be enough. I will stand some up and put to a controller and see what numbers I can get.

 

[bryhan67]

FWIW, up here on the 45th parallel, I have my panels mounted at about 40 degrees East/West and get FULL power around 3pm this time of year.

I have 8x250W panels, 1KW (4) on the East, 1KW (4) on the West. My Midnight Classic reported peak production of just over 2000 Watts on sunny days.

It actually surprised the heck outta me and I had to upgrade the breaker going into my charge controller. I never expected full power with panels positioned East/West, but there you have it!

East facing side:

FWIW, up here on the 45th parallel, I have my panels mounted at about 40 degrees East/West and get FULL power around 3pm this time of year.

I have 8x250W panels, 1KW (4) on the East, 1KW (4) on the West. My Midnight Classic reported peak production of just over 2000 Watts on sunny days.

It actually surprised the heck outta me and I had to upgrade the breaker going into my charge controller. I never expected full power with panels positioned East/West, but there you have it!

East facing side:

Do you have same controller for both east and west? Someone told me to not tie together east and west one side can pull the other down. Anyone know if thats true?

 

[GLC]

What I did was first look on the East side. Normally we have early morning clouds that burn off around 8 am. So I then tracked the sun as it went around the top of my house. Mine is not a "true" East and West orientation. So I found at my roofs angle, and not wasting any collection before 8 am due to the clouds, best sun on the East side was at 10:30 with my roof angle without adding extra PV panel supports. So that gave me 2.5 hours before and after for goon sun. Then I did the same on the west side although I rarely have clouds at the end of the day. Afternoon best sun was at 2:30 so my best sun was 2.5 hours before and after. Now they do collect more PV than just 5 hours but best PV was in that 5 hour window on both sides. On my west side I still collect PV till 7pm.

 

[GLC]

Do you have same controller for both east and west? Someone told me to not tie together east and west one side can pull the other down. Anyone know if thats true?

Personally, for best PV collection, I run different controllers with panels facing different directions.

 

[bryhan67]

Used the PVWATTS and did by hour. I pulled only for one day 7-1-22. Yellow is easy in both 45 and 90 deg and green is west the same. I put in one KW for size. I guess thats 1000 wats of solar panles? East is for the sunrise and west for sunset. Not sure if I agree. Just tilting one panel seemed to show different data. bast on that program 45 to 90 is not that much different. I will play with actual panles. I can measure amps but maybe volts are dropping too. Once I put some to a controller I will know actual watts.

 

[Xhumeka]

Do you have same controller for both east and west? Someone told me to not tie together east and west one side can pull the other down. Anyone know if thats true?

Same controller yes, but I run two strings in parallel (one string for each side) to prevent what you describe.

 

[bryhan67]

Same controller yes, but I run two strings in parallel (one string for each side) to prevent what you describe.

Have you tested it? If one day you only charged from the west and the other day only east? If it adds up to the same.

 

[Xhumeka]

Have you tested it? If one day you only charged from the west and the other day only east? If it adds up to the same.

There aren't many cloudless days for me to accurately test that way, but based on what I've seen with 1 string in deep shade and the other string in bright sun, it works as expected.

 

[littleharbor2]

Have you tested it? If one day you only charged from the west and the other day only east? If it adds up to the same.

Are you in the South Campos? I was thinking Calexico from your zip code but the map you posted shows you right up the beach from my place. I'm in La Roca. Let me know if you want to get together and talk solar.