Overnight you don’t get much sunshine and our batteries drop AH without anything topping them up.
Would a wind generator be a good idea? or would it just make more sense to add more solar and catch up the next day?
So quickly lets compare a wind generator with a power equivalent solar panel.
|Wind Generator||Solar panel|
|Cost: $1500||Cost: $500|
|Maximum Wattage: 450||Maximum Wattage: 400|
|Real world Wattage: |
450w @ 25kts wind
45w @ 12kts wind
0w @ 6kts wind
|Real world Wattage:|
75% on a sunny day : 300W
50% as an average day: 200W
|Average hours of generation/day: 8||Average hours of generation/day: 8|
|Expected Daily output: 360W (based on an average of 8 hours/day above 12kts)||Expected Daily output: 1600W|
(based on 8 hours of average day)
|Cost/Watt/Day: $4.16||Cost/Watt/Day: $0.31|
Seems a no brainer to me, especially given the desire to anchor in calm hot anchorages. But what about the shoulder seasons or winter? would the figures change dramatically? I think they would but still remain on the side of Solar, lets face it we’ve been fairly generous with Wind and it still would need to increase cost/return by 13.5 times to break even.
Expected daily output should be measured in Wh, not W. Cost should be Cost/Wh/day, not Cost/W/day. Units matter. Power v. Energy.
I agree with your conclusion. On most boats the most significant contribution of wind generators is to shade the solar. That isn’t so good.