Panel tilt near the equator

[Skid]

I'm setting up a small system for my son's house which will have two 300 watt panels. A friend is saying they need to be at an 11º angle equal to our distance north of the equator. Thew house sits facing south southeast and the sun rises from behind the left rear corner of the house in summer months and sets on the right front corner, which are the cooler, rainier months here and in the winter months which are hotter and sunnier rises on the front corner and sets about 40º in front of the right side.

I think the panels should be flat to increase production in the cloudier months and not angled to the hotter, stronger months when the batteries will probably be topped up before noon.

As the seasons are somewhat backwards from the typical effects of the north, does this make sense? Everything I see here has the panels tilted to the south but to me it seems like they're not getting the benefit they need in the times when they need it..

 

[Hedges]

Good to orient/slope for the seasons when you want more power.

Slope could let rain rinse dirt.
Series or parallel?
How about one sloped East, one slope West, connected in parallel?

But there is the issue of morning fog/overcast if you get that and it burns off later.

Try an on-line insolation calculator.

 

[45North]

I'm setting up a small system for my son's house which will have two 300 watt panels. A friend is saying they need to be at an 11º angle equal to our distance north of the equator. Thew house sits facing south southeast and the sun rises from behind the left rear corner of the house in summer months and sets on the right front corner, which are the cooler, rainier months here and in the winter months which are hotter and sunnier rises on the front corner and sets about 40º in front of the right side.

I think the panels should be flat to increase production in the cloudier months and not angled to the hotter, stronger months when the batteries will probably be topped up before noon.

As the seasons are somewhat backwards from the typical effects of the north, does this make sense? Everything I see here has the panels tilted to the south but to me it seems like they're not getting the benefit they need in the times when they need it..

I see you are in Nicaragua.
Listen to your friend. Conventional wisdom is to set your panels due south at an angle equal to your latitude.

 

[JWLV]

Panel tilt is usually at the angle of distance from the equator as you stated. But you may deviate from that depending on your expected usage.
Allow me to present an example of that.

I live in Las Vegas, Nevada. My panel tilt should be 36 degrees. But in Las Vegas from May thru September, the weather is extremely hot. In June, July, and August, you can expect up to 110 degrees during the day and 100+ on some nights. So that means I need much more electricity during the summer months for running the air conditioner. My panels are titled 20 degrees so that I can capture the most sunlight during the summer months.

 

[DougfromdaUP]

Listen to Hedges and use an insolation calculator to figure out the best angle.

I don’t know if PVWatts will account for your weather there, but look for one that does. Clouds/fog in morning or afternoon will make a tremendous difference.

Edited to fix spell check induced error

 

[45North]

Panel tilt is usually at the angle of distance from the equator as you stated. But you may deviate from that depending on your expected usage.
Allow me to present an example of that.

I live in Las Vegas, Nevada. My panel tilt should be 36 degrees. But in Las Vegas from May thru September, the weather is extremely hot. In June, July, and August, you can expect up to 110 degrees during the day and 100+ on some nights. So that means I need much more electricity during the summer months for running the air conditioner. My panels are titled 20 degrees so that I can capture the most sunlight during the summer months.

Makes sense!
To optimize for summer, subtract 15 deg (flatter); to optimize for winter add 15 deg (steeper)
If you can be bothered, some people actually change their angle seasonally. (Design your rack with 3 settings for Summer, Spring/Fall, Winter)

 

[1201]

JRC Photovoltaic Geographical Information System (PVGIS) - European Commission

Photovoltaic Geographical Information System (PVGIS)

re.jrc.ec.europa.eu

Has an optimize for location function