We have a Proven 6KW wind turbine that is now about 15 years old. Due to poor site conditions we have never got the output we were hoping for. The solar PV we have since installed separately have been far more consistent.

So, with a spare south facing roof that can hold around 4-6kWH of solar PV, I would like to replace the turbine with PV and feed into the same inverter. Both produce DC electricity.

The output from the turbine starts producing electricity from a nominal voltage of 270V up to a maximum of 600V, I understand. The solar PV panels I have looked at are rated at around 400W and generate up to 38V. So if I were to install 15 of these panels in series then my understanding is that they would produce a maximum of 6KW at 570V (I am not an electrician but studied A level physics many years ago and asked my friendly electrician (who does not install solar PV) and he believes my logic is correct).

The only other main doubt I have would be regarding the output curve of each generator (which I can't seem to find for any specific products) - i.e. the shape of a graph showing wind speed/brightness(lumens?) on the x-axis and voltage output on the y-axis and the way the inverter (SMA 6.3KW Windy Boy) might be optimised to the output of the wind turbine. If those graphs for the turbine and the PV are similar in shape then I see no issue of replacing the feed into the inverter to the PV (or even if the PV graph is steeper (i.e. higher voltage generated at lower light levels than the proportional level of wind speed that the turbine would require).

At this stage I don't want to install batteries but would like to consider adding some later once we work out how much more we could save.

I also don't know who could carry out this installation - my understanding is that the glut of solar PV installers want to fit a complete package including the inverter rather than just a partial install like this.

Any help or advice gratefully received.

And if I find a suitable solution does anyone want to buy my old wind turbine?

Thanks,

Geoff

Meant to ask what setup have you got for the PV you already have. Is there scope for combining with the new.

I have asked SMA but they haven't replied. My experience of customer service is that if there is not likely to be any financial benefit to them (i.e. a new sale) then they're not likely to be bothered to respond.

I am hoping that the names 'Windy Boy' and 'Sunny Boy' were simply marketing names for the same product. Whether there is different configuration to optimise for the energy source I have no idea, hence the question about the output curve (you'd think the technical specs of any product like this would include such a thing but I haven't found it).

The existing PV is on a different roof of a different building with it's own inverter (3KW) and is subject to generous FiTs (which the new solar wouldn't so it needs it's own inverter and generation meter setup.

Posted By: geoff_forwood
The existing PV is on a different roof of a different building with it's own inverter (3KW) and is subject to generous FiTs (which the new solar wouldn't so it needs it's own inverter and generation meter setup.

You would necessarily need a second system. OFGEM changed the FIT scheme rules in 2021 to allow changes of kit and expansion of generating capacity, so you could add to what you already have. You only get paid prorata for the original accredited system size so if you added 3kw of panels to give a 6kw system, youd only get FIT payments for 50% of what you generate/export ie the original 3kw

Thanks for your reply. I am in Devon and my turbine is identical to the one you have linked to on the other thread (except that we have managed 60,000KWH). Typical output is between 4 and 5000kwh per annum.

I already have 2.77KW PV and I understand the DNO agreed a grid connected output of up to 42A, which I calculate to be just over 10KW. If I keep the turbine then I can only add another 1.3KW of PV. From my 15 years of wind experience and 12 years of PV experience, a replacement 6KW of PV would suit me fine. I'm on an E7 tariff so overnight electricity is cheap and I'm home 7 days a week hence why I don't want to install batteries now but rather wait until I can work out what savings the batteries would give me (and maybe we'll invest in an electric car at some point which might reduce the benefit of battery storage further).

Agree with the above.

I've a similar small turbine. The DNO agreed to 2.5kw per phase for the turbine, then I wanted to put some solar on too. They wouldn't up the export allowance but were satisfied with using a compliant, export limited, solar inverter which caps total export at 2.5kw per phase.

Surely even allowing for annual maintenance, 4000+ kWh per year is worth it?