12V Air Breeze on 24V system

Jonne · December 2020

I have on my cabin 2x250W solar with a MPPT regulator on roof
a Air Breeze 12V windturbin with integrated regulator

I consider to buy Victron 24/3000/70-50 and some 24V lithium battery.

I know that my solar system will handle 24V, but what can I do with the Air Breeze wind generator ? I can adjust it up to 17V

mike95490 · December 2020

Sell it and buy more solar PV . 17V is not going to be able to recharge a 24v battery.
To use it, you would need some sort of 12 - 30V step-up gear, and then use another charge controller to regulate the 30V for battery charging.

That inverter is going to suck a lot of power when it's not well loaded, what are you trying to run with only 500w of PV ? I'd like to see your loads be more defined before you start spending $$

Jonne · December 2020

First... My cabin is above arctic circle, in Northern parts of Norway. We don't have sun from des-feb, but we have a lot of wind

Today I have a Studer 12/1600 inverter on 12V system, but I consider this Vioctron 24V

On 500W solar and 2x290 AGM Battery (today) and a little help from Honda EU20 during winter time, my cabin has:
LED 42" TV, radio, downlight, VHF. Parafin heater, shower pump. I have used this system many year, but now the AGM battery have reached 10 year and I think I need new

BB. · December 2020

AGM batteries tend to last around 7 years of so in warmer climates. In very cold climates they tend to "age slower". There is an engineering rule of thumb, for every 10C drop in temperature (below 25C nominal), the "thing" ages 1/2 as fast.... Conversely, for every 10C increase, the "thing" ages 2x faster.

We are not that much of a wind systems forum. And (at least in most places), wind turbines just do not output near as much energy as advertised, and do not last very long/require a bunch of maintenance. Add the cost of a tower to place the the turbine 10-30+ meters in "clear/non-turbulent air", the costs can quickly escalate.

However, if you don't have sun (as in your case), solar panels just are not going to cut it for winter.

In the case of wind turbines, here is one product where a well designed and constructed do it yourself project can be better than any of the 100 commercial turbines out there.

Here are some links to check out:

Wind Power Links
www.otherpower.com (good forum for DIY Wind Power)
Hugh Piggott - Scoraig Wind Electric site for tons of info (from mike90045)
Scoraig Wind "Recipe Book" for DYI Turbines (from Chris Olson... From his 4/11/2013 post)
www.greenpowertalk.org (added from "russ"--Like here but more wind/less solar)
Small windpower a scam ? Survey says SO
Truth About Skystream & SWWP
Windmax HY-2000 2kW Wind Turbine (apparently, some vendors don't sell spare parts--just new turbines. However, the owner, Edward has been very happy with its performance from 2010-2012--BB. 5/31/2012)

For Wind Turbines, finding neighbors that are happy with their choice (local source for turbine, parts, and service) is a good start. I also like to ask about their production numbers. Daily/monthly numbers would be nice (AH @ XX Volts, Watt*Hours per day/month). Many times, when I ask that question, almost nobody can answer that question.

Regarding your AC inverter choices... In general, you want as small as AC inverter as you can use, and lots of conservation for your loads.

Normally, for an off grid power system, I would be suggesting a maximum (just a rough guide)--If you have 500 Watts of solar panels, then a maximum of 500 Watts of AC inverter--Assuming that you are trying for near 100% solar power (no genset, etc.).

Also there are sort of practical limits to wiring... For a 12 volt battery bank, roughly a maximum of 1,800 Watts or so (you are looking at almost 200 Amps of 12 VDC with a maximum voltage drop of 0.5 volts for reliable operation). And a battery bank of ~720 @ 12 VDC (for flooded cell lead acid batteries--AGM batteries do support higher discharge rates).

Lithium Batteries (typically LiFePO4 or similar) are becoming popular for off grid power systems.HOWEVER, for folks that live in near/subfreezing locations, Lithium batteries generally cannot be charged near or below freezing--They need to be kept >~40F/4C for many brands for normal cycling.

Lead Acid/AGM may still be the best choice for your needs.

I always like to go back to loads and your energy needs. A large inverter can be needed (running a microwave for 10 minutes a few times a day, vs running a computer at low power for 12 hours a day for work/home)--But it is very easy to buy cheap/larger inverters that will drain the battery bank at 20-40+ Watts "just turned on" (40 Watts * 24 hours per day = 960 WH per day or as much power as your whole cabin may use otherwise--For a large/cheap inverter).

Typically, use a small inverter (300 Watts?), that you can run 24 hours per day (6 Watts running, less than 1 Watt in "search mode"--Looking for AC loads >~8 Watts, then turn "on"). Get an inverter with a remote on/off switch is handy too (so you only run inverter when needed).

Anyway... Loads define the battery bank. And the loads+battery bank define the charging needs (solar, wind, generator). Looking a load types (VHF = HAM?) 12 VDC input vs 120/240 VAC. Not many general appliances available at 24/48 VDC (heavy trucks, marine can have 24 VDC "appliances").

For a small cabin with limited power harvest (solar/wind), suggest a smaller battery powered system (LED lights, cell phone/small laptop charging, efficient DC ceiling fan, small water pump, radio for over night/quiet time)... And use your genset when more power is needed (water pump to cistern, power tools, large VHF transmitter, daily recharge battery bank in winter, etc.).

-Bill

12V Air Breeze on 24V system

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