My 250 Watts Grid Tie System Cost Analysis

My 250 Watts Grid Tie System Cost Analysis

Monthly Output based on 5 Sun hours per day  = 33.75 KWH

250 watts
250 watts x 4.5 average sun hours x 30 days = 33.75 KWH
or

@ 250w on grid you will get 250w x5hrs of sun exposure x 90 % effc . =1125w/day at 1125 watts x 30days 

=33750 watts H or 33.75KWH

5000 watts
we do: 5 kWp x 4.5 average sun hours x 30 days = 675kWh per month

or 

@ 5000w on grid you will get 5kw x5hrs of sun exposure x 90 % effc . =22.5 kwh/day at 22.5kwh/dayx30days 

=675kwh..

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Return on Investment ROI 

ROI = (Gains – Cost)/Cost X 100

Cost = P20,000
Gains= 33.75 kwh x 12 months x  P11.22 kwh(

Effective Rate for Residential Customer)

Gains = P4,544 in one year

Number of Months:
Cost = P20,000

X=  Cost / 33.75 kwh  x  P11.22 kwh = P20,000 / 33.75 kwh  x  P11.22 kwh = 
  =   P20,000 / 378.675 =  52.81 Months or 4 years and 4 months

Break even =  4 years and 4 months

ROI in 5 years:
ROI = (Gains – Cost)/Cost X 100 = ( 5 years ( P4,544 )  - P 20,000 ) /  P 20,000 X 100
        =  13.6 %

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Reference:
http://eastgreenfields.blogspot.com/2013/07/micro-grid-tie-installation-in-250-kw.html
http://www.wholesalesolar.com/gridtie.html
http://jwilson.coe.uga.edu/EMAT6450/Class%20Projects/Major/Teacher's%20Guide%20ROI.pdf
http://www.kuryente.org.ph/electric-company/rates/128/2015/february



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Batterry AH computation and PV panel ratio:

Para sa 4 pcs na 100w

100W x 4 = 400W

400W x 4H = 1600 WH

1600 WH / 12V = 1600 HIV / 12V = 133.33IH = 133.33 AH 

saan galing yung HIV? sa P=IE = IV.

Kung 1 pc lang na 100w

100W x 4H = 400WH


400WH ÷ 12V = 33.33AH x 2 = 66.66AH

Safe na sa 70AH yung 100W na panel na isa lang



pero x2 yung 133.33 AH kung hanggang 50% DoD lang ang gagamitin mo sa battery mo. yung computation kasi na yan 

from 0% to 100% yung battery. so 266.66 AH ang sapat. dagdagan mo pa ng isang panel and safe ka na sa 300 AH 

battery at 500w na panels

Safe n set up ay 2:1 ratio


AC Fans 60 watts, 4 hrs use = 240 watt-hr 


REF 150 watts, 4 hrs use = 600 watt-hr 


32 in LED TV 60 watts, 4 hrs use = 240watt-hr 


3 x 5 watts LED bulb, 9 hrs use = 135 watt-hr Total Load = 1215 watt-hr 



@ 12V System: Battery Reqt : 1215watt-hr / 12V = 101.25AH x2 (for 50% DOD) = 202.5 AH 


Panel Reqt : 1215watt-hr / 0.7 (efficiency factor) x 4.5 (hrs of sunlight exposure) = 385watts 

You need about 200AH battery and 400watts panel