Total (heliostat) field efficiency, definition of

Hi Michael,

is it correct that total field efficiency includes the following losses:
- cosine
- reflectivity
- shading & blocking
- atmospheric attenuation
- availability
- spillage ?

Please confirm / correct. Thank you very much in advance.

Kind regards

Gary

Hi Gary,

I can confirm your list. The efficiency of each heliostat is the product:
(cosine loss) * ( reflectivity and soiling ) * (shadowing loss) * ( blocking loss ) * (attenuation) * (availability) * (intercept factor - also called spillage).

Mike Wagner
NREL

Hi Mike,
Thank you very much! It is alweays good when assumptions become facts.



Gary

Hello

Is it possible to determine cosine loss or analyse it separately in SAM??

If not, how to detemine it??

Dear Marwan Mohammed,

The power tower model does not report the cosine loss as a separate loss. The results do show the DNI from the weather file and the field incident thermal power, which should help with your analysis.

Best regards,
Paul.