[TRNSYS-users] question on Type 30

[David Bradley]

Vito,
  I am afraid that I do not have the reference here at home. I believe that the 
Type30 model asks for the length of the collector (measured in the plane of the 
collector) and that Type30 calculates the vertical projection internally. If I 
am incorrect about that, could someone please correct me?

> Moreover, I have to configurate a PV generator on a vertical wall too and to
> maximize the energy output I should like to model the PV array with a
> tilt=30° of each PV model but for the shade do I have to use the Type 30 or
> the type 34 (so thinking it as an overhang) ?

Shading of PVs is a hard thing to estimate. Certainly Type30 will give you an 
estimation of how much beam and diffuse radiation is falling on your PV array 
based on other rows in the array. However, because PVs have internal electrical 
connections between the individual cells that act as an open circuit when one 
cell is shaded, shading 50% of a PV will not necessarily result in a 50% 
decrease in power output. Shading effects on solar thermal collectors are much 
more linear and Type30 is intended for use with solar thermal collectors. We 
wrote a PV shading model based on Type30 which tries to put a bracket around 
the effect of partially shading a PV array by making a linear shading 
assumption (shading 50% of the array reduces power output by 50%) and by making 
a "conservative" shading assumption which assumes that a PV partially shaded 
from beam radiation sees no beam radiation. I am unfortunately away from the 
office for the next few days. When I return, I will be happy to send you the 
parameter / input / output list for that component if you are interested. The 
component will be available (with technical documentation) as part of the TESS 
Green Building Component Library when it is released in mid to late November. 
Kindest regards,
  David

-- 
Thermal Energy System Specialists, LLC
2916 Marketplace Drive - suite 104
Madison, WI  53719
USA
Phone: +1 (608) 274 2577
Fax: +1 (608)278 1475
Email: bradley at tess-inc.com
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