Solar

calculator

A KW worth of panels will produce about $190/year of electricity on my roof. In 15 years that's about $3000 worth of electricity so to break even you need installed cost to be < $3.00/watt.

"PVWATTS v.2: AC Energy and Cost Savings"

"Station Identification"
"Cell ID:","0274366"
"State:","Massachusetts"
"Lat (deg N):", 42.37
"Long (deg W):", -71.03
"PV System Specifications"
"DC Rating:"," 1.0 kW"
"DC to AC Derate Factor:"," 0.770"
"AC Rating:"," 0.8 kW"
"Array Type: Fixed Tilt"
"Array Tilt:"," 30.0"
"Array Azimuth:","180.0"

"Energy Specifications"
"Cost of Electricity:","16.6 cents/kWh"

"Results"
"Month", "Solar Radiation (kWh/m^2/day)", "AC Energy (kWh)", "Energy Value ($)"
1, 2.79, 69, 11.46
2, 3.60, 80, 13.29
3, 4.59, 109, 18.11
4, 4.79, 108, 17.94
5, 5.39, 120, 19.94
6, 5.50, 115, 19.11
7, 5.45, 117, 19.44
8, 5.34, 116, 19.27
9, 4.83, 104, 17.28
10, 3.97, 91, 15.12
11, 2.72, 62, 10.30
12, 2.43, 59, 9.80
"Year", 4.29, 1150, 191.06

If you could install a 1KW system at $2.00/watt you make a return of about $66/yr or $66 on a $2000 investment or about 3.3% annual interest on your investment.

=1KW inverter

plugs into wall 1000 watt $253

02130 calculator At 30 degree tilt the average solar is <math>4.29\frac{kWh}{\frac{m^2}{day}}</math> The bedroom roof would probably produce around $220/year at $.15/kwH

existing use

hot water

~30 therms/mo

DIY panels

10w 12v mounts to panel $59

about charge controllersa 555 charge controller

diy instructions

tabbing wire flux pen bus wire diodes

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