Minerva
Well-known member
On my boat we have 2x100W solar charging 3x120ah lead batteries via an MPPT charger. Boat based on West coast of Scotland.
This year we have been ‘blessed’ with a damn sight more wind than sun during our cruise so had to have the fridge off most of the time. This led to the indignity of drinking non-chilled fizz (although it never exactly got warm!!) and non chilled g&t’s!
In the quest to constantly improve comfort on board, it feels like in our situation, wind and solar would be quite complementary. I appreciate some turbines are very noisy, but we saw a few this year that were near silent…
Looking at the power curves of most wind turbines, 12-15kts of breeze would be sufficient to deliver >6a which is enough to power our fridge & instruments. By 20kts they are into significant charging currents.
Three questions;
Firstly, would a separate charger for the wind work alongside the existing MPPT one or would I have to get a combined charger to handle both wind & Solar inputs? These seem to be mostly PWM chargers which at less efficient and thus a retrograde step..?
Secondly, for the “Dump load” to prevent over charging, could this be the form of an inverter powering the 230v feed to the calorifier? The ability of being able to have a warm shower on inclement weather days sounds quite nice!
Thirdly, when we inevitably upgrade to LifoPo4 batteries when these lead ones die, is there and gotchas to bear in mind for down the line we should design in from the outset.
Thanks.
This year we have been ‘blessed’ with a damn sight more wind than sun during our cruise so had to have the fridge off most of the time. This led to the indignity of drinking non-chilled fizz (although it never exactly got warm!!) and non chilled g&t’s!
In the quest to constantly improve comfort on board, it feels like in our situation, wind and solar would be quite complementary. I appreciate some turbines are very noisy, but we saw a few this year that were near silent…
Looking at the power curves of most wind turbines, 12-15kts of breeze would be sufficient to deliver >6a which is enough to power our fridge & instruments. By 20kts they are into significant charging currents.
Three questions;
Firstly, would a separate charger for the wind work alongside the existing MPPT one or would I have to get a combined charger to handle both wind & Solar inputs? These seem to be mostly PWM chargers which at less efficient and thus a retrograde step..?
Secondly, for the “Dump load” to prevent over charging, could this be the form of an inverter powering the 230v feed to the calorifier? The ability of being able to have a warm shower on inclement weather days sounds quite nice!
Thirdly, when we inevitably upgrade to LifoPo4 batteries when these lead ones die, is there and gotchas to bear in mind for down the line we should design in from the outset.
Thanks.