12 volt system mixed 100 watt panels and 500 wind turbine

BAdams67

Ok, newish to alternate energy - I have a 12 volt system mixed 100 watt panels (9) and (1) 500 watt wind turbine all running through two 30 amp controllers. Battery banks are split into three banks (3 AGM’s 14.5 v max each) in series. One controller for 9 panel and one controller for four other panel. They are tied into a 12 v battery bus bar. The 500 watt turbine is connected directly to the battery bus. My two question are, am I over killing my system with too many batteries connected and second can I go directly from the turbine into the battery bus (solar is not maxing out battery’s yet)?  I use my system for turtle pond pump, shed motion lights, yard cameras, and hopefully the small deck fridge. I push all the output into a Patriot Generator for consistency for now as it shows me my output wattage. Images below 

BAdams67

Images

BB.

Welcome to the forum.

Lots of questions... To give some quick answers:

• three banks (3 AGM’s 14.5 v max each) in series... (the white+blue batteries?)

Technically your three batteries are in Parallel.. If you had them in series that would be a 36 volt battery bus.

It looks like your AGM batteries are 65 Amp*Hour (AH) rating? Three in parallel would be 3*65=195 AH @ 12 volt capacity.

Using our rule of thumbs as a starting point. A reasonable starting point is a 10% rate of charge (5%-13%+ is the typical range). The size of solar array would be:

• 195 AH * 14.5 volts charging * 1/0.77 solar panel+controller deratings * 1/0.10 rate of charge = 367 Watt "nominal" array

You could go as high as 20% rate of charge (would be ~734 Watts suggested max array)--But I suggest using a charge controller with Remote Battery Temperature Sensor. With high charging current it is possible to overheat the batteries otherwise.

You have some other black batteries too? Part of the white and blue battery bank or a separate system?

With Wind Turbines, they rarely produce rated power, and many times (how they are mounted, different brands, etc.) rarely produce any useful amounts of power.

Do you have a Missouri Wind and Sun "dump" controller? This would generally be used (with a resistor load bank) to dump excess wind turbine during high wind and a fully charged battery bank. Yes, it is possible to overcharge a lead acid/AGM battery bank and ruin it with too much charging current/voltage.

I cannot tell from your photos--Do you have fuses/circuit breakers to protect against short circuits? Batteries can output 100's of amps or more into a dead short and can easily get those wires red hot and start a fire.

Say your system is around Tacoma Washington... Fixed array tilted to 47 degrees from horizontal, facing south... The amount of sun it would receive is (don't worry about the AC Energy column for now):

https://pvwatts.nrel.gov/pvwatts.php

Month	Solar Radiation ( kWh / m2 / day )	AC Energy ( kWh )
January	1.92	29
February	2.87	39
March	3.91	58
April	4.41	62
May	4.39	62
June	4.85	66
July	5.78	79
August	5.40	74
September	4.83	65
October	3.49	51
November	2.01	29
December	1.81	28
Annual	3.81	642

The average sun would be 4.85 hours of sun per day for June. The amount of AC energy (20 year average) would be:

• 900 Watts of panels (?) * 0.52 average solar system AC efficiency * 4.85 hours of June Sun = 2,270 Watt*Hours of AC power per average June day.

Normally, I would suggest you use 50-65% of "predicted power" to allow for cloudy weather and such. or roughly (1/2) 1,135 WH of AC power per day). (i.e., if you have some cloudy weather, you don't want to shut the system down or reduce your loads--A pain to manage).

However, you are also limited by your overnight energy storage... For a 195 AH battery bank, usually use 25% to 50% capacity per day (1-2 days of storage). Typical would be:

• 195 AH * 12 volts * 0.85 AC inverter eff * 0.25 battery capacity per day = 497 Watt*Hours of battery storage per day

I don't know enough about your system (battery bank AH?, AC inverter size, your Watt*Hours per day usage, etc.)... And I usually ignore the contribution of a wind turbine (may be of some use during windy/stormy weather--But need to confirm your turbine production/harvest).

Jumping into the middle of an existing system can be confusing. Ideally, I suggest starting with your daily energy needs (Watt*Hours) per day, your location, full time off grid or just a weekend/sunny weather system, etc., then go through the design steps (battery bank size, solar array size, charge controller sizing, AC inverter sizing, etc.). Once you have the system sizing, then do a (few different) paper designs. Then finally purchase the equipment.

 I would be concerned about your wiring right now. Mix of wire sizes (no fuses?), corroded connections(?), and random wiring (wiring should be cleaned up, use bundle ties to make cleaner cable routing, etc.). It is just too confusing for me to really understand what your actual system is (battery banks--how many, mixed AGM with flooded cell or what? Size of inverter, your expected loads, etc.).

Note that adding a refrigerator moves a "small" solar system to a medium (and more expensive system). Refrigerators use a lot of energy, and even water pumps/air pumps for ponds can use a lot of energy too. Solar power is not "cheap"--Measuring your loads, and doing as much conservation as you can will give help you design and build a more "optimal" solar power system--That meets your needs.

Also some places just do not have a lot of sun... Especially during the winter... For example, Tacoma has reasonable sun in the summer, but poor sun in winter--Anything less than (roughly) 3 hours of sun per day ends up needing a much larger array and/or backup power (genset, etc.) to provide reliable electric power.

-Bill