[RE-wrenches] Best angle - direct grid tie

[Darryl Thayer]

Look again at Assistant, you will find that Latitude is not indicated.
Go to SunEye.com or (solmetric.com) they have a nice egg diagram that shows the best angle, you can also find the effect of tilt and Azimuth on peerformance. 

Also there is a NREL software program that will calculate maxium payback.  

You are correct, the best angle is not Latitude, her in Minneapolis the best angle is 37 degrees/TMY3 and Solmetric.  

Also the solmetric PV design software is really excellent for design 
work.  

PVWatts can be sed to find the best angle.  



--- On Mon, 1/4/10, Drake Chamberlin <drake.chamberlin at redwoodalliance.org> wrote:

> From: Drake Chamberlin <drake.chamberlin at redwoodalliance.org>
> Subject: [RE-wrenches] Best angle - direct grid tie
> To: "RE-wrenches" <re-wrenches at lists.re-wrenches.org>
> Date: Monday, January 4, 2010, 7:30 AM
> 
>  
> Hello Wrenches,
> 
> 
> My Solar Pathfinder Assistant (SPA) claims that the optimum
> tilt angle
> for the solar modules is latitude.  I'm
> skeptical.  The system
> being designed is a direct grid tie, ground mount. 
> 
> 
> It seems to me that an angle of latitude will give a
> balanced angle for
> both summer and winter charging.  Since there is far
> less energy
> available in the winter, is this balance really the
> best.  Also, a
> flatter angle in the summer should gain more hours of sun,
> since the sun
> goes N of the E-W axis.  
> 
> 
> With ballasted systems, the 15 degree angle is supposed to
> work just
> fine, due to better summer charging.  Does anyone have
> an answer to
> what really is the optimum tilt angle for a direct grid tie
> system? 
> Is the SPA geared toward off grid systems, or is latitude
> really the
> best? 
> 
> 
> Thank you and best wishes for the New Year, 
> 
>  
> Drake Chamberlin
> 
> Athens Electric
> 
> OH License 44810
> 
> CO License 3773
> 
> NABCEP TM 
> Certified PV Installer 
> 
> Office - 740-448-7328
> 
> Mobile - 740-856-9648  
> 
> 
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