Is there any advantage of panels tilted slightly west over east or vise versa if those are your only options?

[Joe_]

Because of constraints I am flat mounting my panels in two arrays, but not exactly flat. I can't tilt them south but will have to tilt them east or west to give the best chance of water running off them after a rain. The simple least expensive method gives me a tilt of .8 degree east or west, my choice. By adding some money and labor I could increase that to 1.3 degrees either east or west. There are a lot of small arrays of panels, 14 arrays of 2 panels each that this applies to.


Does it matter which direction I choose to tilt them as far as solar output? . I could also tilt one group of 14 panels to the east and the other to the west.
Does adding a half a degree of tilt to the .8 degree tilt east | west tilt accomplish anything of value?
Thanks
Joe

 

[OffGridInTheCity]

You might use a tool like PVwatts - https://pvwatts.nrel.gov/pvwatts.php - and type in the azimuth, panel kw, and angles and it will show you expected PV for you're specific location based on recent weather. It's a quick/easy tool to use.

Try the various options and compare the results. This will give you specific data and the degree of differences between the scenarios to help make a decision.

Agree that a slight tilt is useful to encourage self-cleaning via the rain and worth it even if the PV output doesn't make much difference. Flat panels get pooled water as the water can't run off the slightly raised edges which leads to dirt residue as the water can't run off but evaporates.

 

[Joe_]

You might use a tool like PVwatts - https://pvwatts.nrel.gov/pvwatts.php - and type in the azimuth, panel kw, and angles and it will show you expected PV for you're specific location based on recent weather. It's a quick/easy tool to use.

Try the various options and compare the results. This will give you specific data and the degree of differences between the scenarios to help make a decision.

Agree that a slight tilt is useful to encourage self-cleaning via the rain and worth it even if the PV output doesn't make much difference. Flat panels get pooled water as the water can't run off the slightly raised edges which leads to dirt residue as the water can't run off but evaporates.

Thanks for the suggestion.
According to the calculator it makes no difference which direction they are tilted, east or west .
The angle is too small aperently To matter.

 

[time2roll]

What are your weather patterns? Many areas have more fog or clouds in the morning that will block the east sun. Or mountains on one side could cut off from the east or west.

If feeding the grid consider TOU rates are often higher in the afternoon so the west sun helps a bit.

 

[Zapper77]

Thanks for the suggestion.
According to the calculator it makes no difference which direction they are tilted, east or west .

Morning fog vs evening thunderstorms

 

[Joe_]

I’m in the southwestern desert. Sunny clear sky’s, blistering heat, right up to torrential downpours on and off for a month every year or so maybe. No fog. Very few thunderstorms. Was 113 in the shade one day this week. The rest of the week it averaged 111.

 

[JunglePower]

Because of constraints I am flat mounting my panels in two arrays, but not exactly flat. I can't tilt them south but will have to tilt them east or west to give the best chance of water running off them after a rain. The simple least expensive method gives me a tilt of .8 degree east or west, my choice. By adding some money and labor I could increase that to 1.3 degrees either east or west. There are a lot of small arrays of panels, 14 arrays of 2 panels each that this applies to.


Does it matter which direction I choose to tilt them as far as solar output? . I could also tilt one group of 14 panels to the east and the other to the west.
Does adding a half a degree of tilt to the .8 degree tilt east | west tilt accomplish anything of value?
Thanks
Joe

About a year ago, I added four supplement 400w panels to my rooftop with another controller. being at latitude 9.5N they are almost horizontal with two facing ESE and the other two WNW. I researched their connections and ended up with each pair wired in parallel then the two pair into series. Seems to work quite well, outperforms the eighteen 20yo poly 100amp panels by hundreds of watts. Morning sun charges very early in the day and the evening sun continues to maintain a good charge.