PV modules are rated in DC watts, utilities net metering is calculated in AC watts. Does anyone recall the engineering conversion from DC to AC watts? Can anyone identify the typical inverter's DC watt input to AC watts output conversion/results?
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dc watts = ac watts Watts are a measure of power or heat. 5V DC @ 1 A = 5W, same with AC 5VAC @ 1A = 5W
As for inverter conversion losses, they vary widely from 60% to 95%, somewhat tracking price, higher price = higher efficiency. (not counting ebay inverter scams)
Reputable mfgs publish an efficiency chart for their inverters
Hope that helps. Mikespreadsheet based voltage drop calculator:
http://www.solarguppy.com/download/...calculator.zip
http://www.solarpaneltalk.com/showth...osscalculator
http://www.mikeburgess.org/PVinfo_2.html
solar: http://tinyurl.com/LMRSolar
gen: http://tinyurl.com/LMRLister ,
battery lugs http://tinyurl.com/LMRBigLug
Setting up batteries http://tinyurl.com/LMRNiFe
gear :
Powerfab top of pole PV mount  Listeroid 6/1 w/st5 gen head  XW6048 inverter/chgr  Iota 48V/15A charger  Morningstar 60A MPPT  48V, 800A NiFe Battery (in series) 15, Evergreen 205w "12V" PV array on pole  Midnight ePanel  Grundfos 10 SO59 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run  Runs off PV 
 Midnight Classic 200  10, Evergreen 200w in a 160VOC array 
 VEC1093 12V Charger  Maha C401 aa/aaa Charger  SureSine  Sunsaver MPPT 15A 
DC watts minus inverter loss = AC watts credited?
Mike90250, Thanks for your reply.
If for example, a gridtied, 1kW DC system, is connected to a 95% efficient inverter, assuming that is the total loss (assuming unity power factor), are you saying the utility will recognize the contribution of 950 W AC?Comment

Originally posted by crlare View PostMike90250, Thanks for your reply.
If for example, a gridtied, 1kW DC system, is connected to a 95% efficient inverter, assuming that is the total loss (assuming unity power factor), are you saying the utility will recognize the contribution of 950 W AC?
Depending on your meter. Some meters run backwards, some run forward as you feed, and you pay for what you give !! When you get permitted grid tie, they change the meter to the type to match your service. If you have just installed the system and they have not changed the meter, you may get odd results.spreadsheet based voltage drop calculator:
http://www.solarguppy.com/download/...calculator.zip
http://www.solarpaneltalk.com/showth...osscalculator
http://www.mikeburgess.org/PVinfo_2.html
solar: http://tinyurl.com/LMRSolar
gen: http://tinyurl.com/LMRLister ,
battery lugs http://tinyurl.com/LMRBigLug
Setting up batteries http://tinyurl.com/LMRNiFe
gear :
Powerfab top of pole PV mount  Listeroid 6/1 w/st5 gen head  XW6048 inverter/chgr  Iota 48V/15A charger  Morningstar 60A MPPT  48V, 800A NiFe Battery (in series) 15, Evergreen 205w "12V" PV array on pole  Midnight ePanel  Grundfos 10 SO59 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run  Runs off PV 
 Midnight Classic 200  10, Evergreen 200w in a 160VOC array 
 VEC1093 12V Charger  Maha C401 aa/aaa Charger  SureSine  Sunsaver MPPT 15AComment
Comment