Solar Lakeside?

[pedro malo]

To all you solar experts out there Lakeside.

Does anyone know what the ideal stationary angle/roof pitch would be specific to the latitude of Lakeside to maximize the efficiency of solarvoltaic panels between summer and winter?  I know in my part of Washington State it is 33 degrees but not sure if that applies to specific latitude or the entire northern hemisphere?

Need help from experts.

Many thanks!

 

[conejorapido]

There is formula for this but a installers I've talked with use an angle close to the local latitude which is 20 degrees approx. Check google and you will find the actual formula.  My panels are at 20 degrees and I'm very happy with the results

[MyHomeSweetHome]

You could call Matt at 331-041-3456

[Cookie]

So... what are the average costs Lakeside now for say a 2000 sq ft house?  Just ball park..

[El Saltos]

Under $5,000USD.

[John Shrall]

The cost of any solar system will depend on the amount of kilowatts the system generates. My 3.072 kWh system (24x128 watt) has generated 17kWh/day over the last 5 years.

I believe 20 degrees or so is correct also, plus a southern alignment is beneficial.

I have a neighbor in Guayabitos that installed a system much larger than mine but chose to use a 10% angle and oriented them to the southeast due to the location of a flat roof over a carport right on the street. He produces far less on average than me even though that part of Mexico generally gets more hours of sunshine than we do.

Direction and angle can make a difference in production.

[Go Solar]

20 degrees incline, and south orientation, is ideal @ lakeside.

Re the Guayabitos installation that John mentions, the loss is more likely due to being SE than the 10 degree inclination.

10 degrees makes only about a 2% overall year round difference in production compared to 20 degrees, and will actually give slightly better results in summer (sun directly overhead more of the day) and a bit less in winter (when sun is at a lower angle)

 

[snowyco]

20 degrees incline also stays much cleaner,  as the 10 degree incline collects more dust and does not rinse off as well when it rains.

You can gain roughly 10% more power during May - August if the panels are aimed north during that time,  as the sun stays  north of vertical almost all day during those 4 months.

 

[pedro malo]

2 hours ago, conejorapido said:

 

Thank you everyone!  I was able to find a calculator and it confirms all your information.  At 20 degrees N, the fixed angle recommendation is 17.4 degrees with an efficiency rating of 72%.  So Joco is 20.2830 N so 20 degree incline should be about right.

Thank you all for the education and your generosity!

[Cookie]

1 hour ago, John Shrall said:

The cost of any solar system will depend on the amount of kilowatts the system generates. My 3.072 kWh system (24x128 watt) has generated 17kWh/day over the last 5 years.

I believe 20 degrees or so is correct also, plus a southern alignment is beneficial.

I have a neighbor in Guayabitos that installed a system much larger than mine but chose to use a 10% angle and oriented them to the southeast due to the location of a flat roof over a carport right on the street. He produces far less on average than me even though that part of Mexico generally gets more hours of sunshine than we do.

Direction and angle can make a difference in production.

I guess my question would be for the normal NOB consumption.

[John Shrall]

With no A/C or heat how can one compare to NOB consumption?

Here it's pumps, refrigerators, lights, TVs and computers. 

[pedro malo]

1 hour ago, snowyco said:

20 degrees incline also stays much cleaner,  as the 10 degree incline collects more dust and does not rinse off as well when it rains.

You can gain roughly 10% more power during May - August if the panels are aimed north during that time,  as the sun stays  north of vertical almost all day during those 4 months.

 

My not sure if I understand this.  Are you saying that during those months one could pivot the panels from facing south, 180 degrees to the north and gain another 10% efficiency?  I imagine changing the degree of incline would also increase efficiency?

[John Shrall]

Your results may vary but having recorded monthly readings for the last 5 years, here's my order of months with the highest to lowest production.

Mar, Apr, Feb, May, Oct, Sep, Jan, Jul, Aug, Nov, Jun, Dec. The average daily kWh production for me ran from 19.26 in Mar to 15.65 in Dec.

Summer months here trail the pack with Feb, Mar and April always leading. The sun may be lower early in the year but the days are generally without clouds..

While days in the summer months may be longer, the cloud cover during the rainy season affects solar production a lot.

[777]

Call EcoSmart at 331-041-3456, for comparison prices.

[pedro malo]

How does a grid tied system work with CFE.  If you produce more electricity than consume, does the meter run backwards?

[snowyco]

4 hours ago, pedro malo said:

My not sure if I understand this.  Are you saying that during those months one could pivot the panels from facing south, 180 degrees to the north and gain another 10% efficiency?  I imagine changing the degree of incline would also increase efficiency?

You have the general idea.  Since the sun spends pretty much all its time in the Northern sky (at our latitude) during May through August, you can either buy an extra 20% or 30% more panels than your minimum expected needs to make up for the panels aimed in the wrong part of the sky,   or   you can aim the panels at the Northern sky for 4 months of the year to minimize the losses.

One way is to have adjustable mounts,   where you point the panels at the Southern sky 8 months of the year,  and aim them at the Northern sky the other 4 months - like having the panels on a teeter-totter.

This can be done with tilting mounts,  potentially with quick disconnects & re-connects.  

Other people do it by mounting their panels on 'daisy heads' - where the whole 'daisy head' is simply rotated to face North for 4 months of the year.

The 'daisy head' mounting system also is compatible with adding motors to rotate the panels to track the sun...   gaining another 40% - 60%, but I have not calculated the time for ROI.

Here are some examples of classic daisy head mounts:

http://www.invertersupply.com/index.php?main_page=product_info&products_id=5577

[snowyco]

Again,  some people choose to just buy an extra 30% more panels and a bigger inverter (or more small inverters), if  $$ costs are not an issue.

[Go Solar]

2 hours ago, pedro malo said:

How does a grid tied system work with CFE.  If you produce more electricity than consume, does the meter run backwards?

The "solar" CFE meters are a true enabled bi-directional meter and record 2 sets of values; use from CFE, and what is sent to CFE.    The bi-monthly bill is based on the difference between the two, and any credits are carried forward on a 12 month rolling basis.

From a system sizing / billing standpoint, the ideal place to be is to have net use from CFE in the 250 to 300 kWh range per 2 months (or about 4 to 5 kWh per day).    This keeps you at the lowest rate step(s) while not needing to over$ize the system.   ;-)

Feel free to PM with any questions or needs.

[pedro malo]

1 hour ago, snowyco said:

You have the general idea.  Since the sun spends pretty much all its time in the Northern sky (at our latitude) during May through August, you can either buy an extra 20% or 30% more panels than your minimum expected needs to make up for the panels aimed in the wrong part of the sky,   or   you can aim the panels at the Northern sky for 4 months of the year to minimize the losses.

One way is to have adjustable mounts,   where you point the panels at the Southern sky 8 months of the year,  and aim them at the Northern sky the other 4 months - like having the panels on a teeter-totter.

This can be done with tilting mounts,  potentially with quick disconnects & re-connects.  

Other people do it by mounting their panels on 'daisy heads' - where the whole 'daisy head' is simply rotated to face North for 4 months of the year.

The 'daisy head' mounting system also is compatible with adding motors to rotate the panels to track the sun...   gaining another 40% - 60%, but I have not calculated the time for ROI.

Here are some examples of classic daisy head mounts:

http://www.invertersupply.com/index.php?main_page=product_info&products_id=5577

 

1 hour ago, Go Solar said:

The "solar" CFE meters are a true enabled bi-directional meter and record 2 sets of values; use from CFE, and what is sent to CFE.    The bi-monthly bill is based on the difference between the two, and any credits are carried forward on a 12 month rolling basis.

From a system sizing / billing standpoint, the ideal place to be is to have net use from CFE in the 250 to 300 kWh range per 2 months (or about 4 to 5 kWh per day).    This keeps you at the lowest rate step(s) while not needing to over$ize the system.   ;-)

Feel free to PM with any questions or needs.

You guys have been unbelievably helpful!

I really like the teeter totter mount idea!  I have an un-obscured southern exposure.  I want to incorporate the panels as part of my mirador awning.  Build the awning at a 20 degree pitch facing south.  Would the teeter-totter mount have enough range of tilt to bring panels up from the 20 degree incline facing south to the correct position toward north I wonder?  Sounds like a mount hinged at the northern end would have more range of movement to tilt up toward north?  The daisy mount will not work for me and would be an incredible eye sore on the mirador.   Hmmm, I imagine I could have my blacksmith fabricate the mounts to my specifications if not available commercially?

Thank you so much for the great ideas!

[El Saltos]

IMHO, we have so many great solar days here that fiddling with seasonal realigning of panels is not worth the expense, time, and effort.  Any of the system providers here can properly size your system to keep you out of the DAC rate.  Then, your only maintenance chore is cleaning the panels once per month during the dry season.  My gardener does that for me. s

[MtnMama]

About 15 years ago, when we lived off-grid in the Colorado high country, we attended a solar seminar at NREL ( National Renewable Energy Laboratory). They suggested that changing the tilt was rarely worth the added expense and bother and that was in Colorado where the change was more pronounced.

[Go Solar]

Agree 100% with the previous posters about staying with fixed panels.

FYI:

Chapalaweather.net is a great resource for solar info & data.

5 day solar power graphs are about 1/2 way down the page.

And a link to detailed historical data is to the left of the web-cam image.