connecting a wind turbine to my existing solar setup.

[bony999]

Hello All

I am sure that with the wealth of advice and guidance on here, someone will be able to give me a definitive answer to the above topic. At present I have an inverter and solar setup running nicley on a conversol V4 with 2 pylontec us 5000  batteries and it is powering my home on a seperate consumer unit that supplies the power to the whole house. The only thing currently on the mains supply is the lighting.(working on that too).

My question is this. If I get a wind turbine set up in my garden and run the output from it into my solar power cupboard, how can I best use the wind turbine output to add to my existing solar setup. I have another Axpert MKS4 inverter that I have repaired this has two solar inputs and initially I was thinking of changing the inverters over and then connecting the wind outut in, to the second pv input as an additional source of power. )The solar produces 230v total so I have enough for another 220v to reach may 450V input).  I suspect that this may be an issue if the supply from the turbine fluctuates when there are two inputs as this will effect the mppt tracking but I am not 100% sure of why. In any even I suspect it will not work well if there is no solar and the wind power is not producing enough to start the inverter.

I would consider adding the second inverter (the axpert) to my cupboard and then supplying this with wind power as its only input and possibly using a small pylontec battery to enable the inverter to stay on when the wind power is too low to power it but I am not sure if I could then add the 230V output in to my consumer unit along with the 230V from my solar setup.

Would I need to add a diode to the supply from both so that they do not feed back to each other or is it simply a case that when the supply comes out of each inverter they have internal protection to stop this happening anyway? I realise the wind turbine setup needs a shunt etc and have accounted for this in the setup but I am at a bit of a loss as to the best way to connect the output the wind turbine produces. My initial idea is for something along the lines of a 1 to 2 Kw turbine as an added small source to the system, a bit like a trickle charge to the system. I know the turbines don't produce what they state on them but I figure that any input is still a bonus for the days when the sun is not shining.

As ever I would welcome any assistance or for that matter a pointer to someone who has already done this and can tell me the pitfalls of doing this. I know it is not going to produce tons of power but any is better than none.

 

Regards

Bony999

 

[macafrican]

I’d look at how boats handle wind turbines  - they could have shore AC power plus DC solar plus DC engine alternator plus wind (AC or DC) and have two battery banks plus battery inverter(s).   My gut feeling is a DC charge controller from wind turbine that supplies common DC bus to which you hook the battery inverter and battery.   The battery BMS would not know or care who supplies DC or draws DC so view that DC busbar (or DC combiner) as an interchange?

I don’t think hooking wind into MPPT solar input of Axpert is a good idea but could be wrong.   Very different power management, more than likely the wind charge controller can do a lot of other things to turbine.

[bony999]

Hi macafrican

thanks for getting back to me, I will look into your suggestion. I am in the dark with wind and combining it to a solar setup so that looks like a good place to start.

Many thanks and Regards

Bony999

[Powerforum Store]

Hello 

You may have a few problems integrating a turbine with the system. 

Coupling the turbine to the MPPT Controller of your axpert inverter is not necessarily a great Idea.

Firstly your controller choice for the wind turbine would be problematic. 

A lot of the cheap chinese vertical axis and horizontal axis wind turbines that are punted in South Africa either comes with a 48V MPPT Controller which is cheap and nasty the dump loads that come with these machines are inadequate and almost always burn out then leaving your turbine without any method to dump excess power that it may produce.

These controllers are not user adjustable and need to be factory configured to match your lithium battery exactly.

These types of controllers default configuration is for lead acid compatibility. 

The Controller converts the 3 Phase variable frequency voltage and amperage your turbine generator produces into usable DC Power some wind turbines have the controller built in however these types of machines are more focused on marine applications meaning the output of the built in controller is only compatible with lead acid battery types. 

So risk of damaging your Lithium battery with these types of controllers are very very high some will argue the BMS will protect the battery however I have had a few clients contact me that imported these turbines with their controllers themselves and ended up with damaged Lithium Batteries that the suppliers will not repair under warranty. 

The other type of controller you get with your cheap Chinese turbines is the grid tied controller these require a reference voltage and frequency to work meaning they have to connect to ESKOM or to the backup port of an inverter so that they can produce power. 

Problems of these types of controllers are as follows 

They are not NRS Compliant they do not have CT Clamps to prevent or limit export to grid 

They are not load bearing they simply generate power at a slightly elevated voltage (230 VAC) 

Because the controllers are very cheap you will also find that the dump loads are inadequate. As a rule of thumb the wind turbine dump load needs to be at least 1.5 to 2 times the rated capacity of the turbine meaning a 500 Watt turbine needs a 750 watt to 1 KW dump load. 

A dump load is a resistive load that can be activated by the controller to divert unused power and is also used as a braking mechanism for most fixed blade turbines. 

There however are MPPT Controllers in the market that can produce 600VDC that can be coupled to an MPPT however the MPPT has to be very advanced and reactive. 

As an example SMA inverters are capable of accepting these types of configurations and they have special settings and features that support this type of integrations the Same goes for Solis inverters. Because the Solis and SMA inverters are NRS approved you can then Legally grid tie these inverters to the grid or you can use them in an AC Coupling configuration. 

Sunsynk / Deye  also claims that you can couple a Wind turbine to their MPPT however we still need to investigate if the Advanced MPPT Controllers that can output 600VDC will be compatible at risk of damaging a Sunsynk or Deye inverter however untested they are also very vague of what type of wind turbine controller is required I have looked into those options and there is no clear information available besides that the majority of wind turbine controller manufacturers do not provide a vast range of options for their controllers. I would be very interested in hearing of anyone that has successfully integrated a Chinese wind turbine with a Sunsynk or Deye MPPT controller without damage or difficulty. I know of one product that claim they have however they have a special controller to achieve this. 

Axpert Voltronics based inverters MPPT Technology is not very advanced and not fast enough to adapt to fast voltage changes so I suspect that if you try to couple a high voltage MPPT based wind turbine controller to the Voltronics MPPT you may just end up destroying the MPPT of the Voltronics inverter also untested. 

The Voltronics MPP also does not allow any functional setting adjustments and just have SOLAR compatible programs so I would be very cautious of trying to do this at risk of damaging the inverter. 

Voltronics / Axpert inverters do not support AC Coupling and the Grid tied inverter will not be able to connect to the ESKOM or Utility input of the Axpert inverter because without Utility power because the grid tied inverters needs a reference voltage and frequency to switch on. 

The Safest integration with your Voltronics / Axpert based inverters is to connect the controller to the battery however this is not the ideal way to integrate because of the following problems you may experience. 

The controller must be configured to match your brand of lithium battery by the factory that the controller comes from and must be MPPT based controller not PWM. 

Once you have achieved that the turbine will generate power to charge the batteries and produce power while the batteries are empty however when the battery is full 

The inverter with BMS coms will not be able to use potential power generation form the Wind turbine controller coupled to the battery in essence the Inverter gets a signal from the BMS of the battery to stop charging the battery and the basically decoupling the DC Bus between the battery and the inverter this applies to most modern inverters that has BMS coms with the battery. 

Then the turbine will activate its dumpload and brake the turbine to stop producing power because based on the voltages set by the factory for the wind turbine controller the battery is full and therefore does not need to be charged by the turbine. 

This means even if there is potential power production available from the turbine it will not be able to run because the battery is full only when the battery voltage drops below 100% will the turbine then start producing power.

The down side of this is that the battery will get cycled a lot more in that event. 

I hope this gives you some idea on how this integration of wind power would work with your Voltronics inverter 

 

 

[Powerforum Store]

Wind turbines are rated at a Nominal wind speed for example our 2 KW variable pitch wind turbine will produce 2 KW @ 9 Meter per second wind or 32.4 Kph 

up to that point they have a power curve and depending on the product will determine what the curve looks like 

How we calculate the potential production of the wind turbine would be then based on an average wind speed of the area where the turbine is to be implemented. 

So lets assume that your average wind speed in your area is 6MS or 21.6 KPH then our 2 KW turbine should produce the following 

@6MS = 21.6 KMPH AEP = 5950 KWH per Year = 16.30 KWH Per Day the AEP is the Annual Energy Prediction conservitavely taking gusts and other factors into account that could affect how efficient the turbine would work. The Power curve states that the turbine should under ideal wind conditions produce @6MS = 21.6 KMPH wind speed 750 Watt.

Your average wind speed for an area is calculated over a year and the assumption then would be 24 hours per day 365 days per year. 

Therefore you AEP would also be calculated over a year.

I hope this makes sense. 

So before you consider a turbine you need to make sure that the area you are situated in has enough average wind speed for the turbine to be viable. 

a good way to get a good idea of what the average yearly wind speed in your are is by using Meteoblue 

simply type the following phrase into google search 

Yearly average wind speed for (Your Location or area) 

Example 

The Yearly average wind speed for Colesberg 

https://www.meteoblue.com/en/weather/historyclimate/climatemodelled/colesberg_south-africa_1013076

So as you can see the yearly average wind speed data is then available to calculate your average and looking at the Data quickly says that Colesberg has a reasonable strong average wind speed you can also see the predominant wind direction this will enable you to locate the turbine in the most ideal position. 

Strong winds will affect Fixed blade turbine differently to Variable pitch Wind turbines. 

Fixed blade turbines have various methods to try to maintain constant rotor speeds by activating dump loads for electromagnetic braking or the tails turning the head of the turbine out of the wind disrupting production.

Where variable pitch turbines simply change the pitch of their blades to maintain constant rotor speeds form 2 to 25 MS winds.

Variable pitch turbines therefore can produce a much higher average production and have a much longer mechanical lifespan than fixed blade turbines. 

Turbines are affected by any tree building or structure in the way of its predominant wind direction. So the turbine has to be higher than any of those obstructions. 

Turbines will make their rated power if the wind is non turbulent and directional. 

One obvious advantage of wind power over solar power is the fact that it can produce power on a 24 Hour cycle versus solar power that only produces power on average for about 4 hours per day per year. 

Advantages of the 24 hour production is double sided. 

It reduces the base load of a system by producing constant power thus reducing the load on the battery system extending battery life potentially. 

Produces power over 24 hours accumulated production is considerable as an example  500 watt per hour over 24 hours is 12KW meaning 12KW produced and 12KW not used from battery.. 

 

[bony999]

Hello Powerforum store

I am very grateful for your full and comprehensive reply, it certainly gives me a lot to think about.

Looking at what may be  number of issues with my current inverter I may look into getting something that is designed to work with a turbine and perhaps a seperate battery to charge with it. Then I could have a seperate system to produce 230V power that I could then try to integrate with my current solar setups consumer unit.

I have read so much on the forums about the issues of wind power and I did not really think it would be so straight forward as to just add it to my current setup. If the turbines are designed for non Li-Ion batteries I guess I will be stuck with gel type leisure batteries as my store and a turbine,charge controller, inverter, shunt and safety devices.

I do not have the room to add more solar panels so I was considering wind as an option to add more 230V power to my existing off grid setup. I am very grateful for the level of detail you have provided and it has certainly made me realise there is a bit more to this wind power than adding it to a solar setup.

Regards

 

Bony999