serious worries.

[GaryM]

Moggy, I posted some figures from PVSOL above somewhere with different inverters and found the TL4000 to yield the most. Are you not a believer in figures from PVSOL? I know it's not the real world though it's all I have to go on.

 

[moggy1968]

no I'm not I'm afraid!!
It's a guide, a start point thats all.
For a 3.29kW system a 4kW inverter is way overspecced.

You look at what the software sugests, then look at it yourself in detail using your own skill and experience to come up with a choice suitable for the array.
You don't just fit whatever the computer says!!

For example, I've just run this through Sunny Design and it gives the green light for everything from a SB1200 to a SB5000!
I haven't look at this scenario in detail (and don't have the time to do so) but I would be looking at inverters between 3000 and 3600w

 

[SolarCity]

I get a bigger yield with an IG TL 30 on this system. I agree that the inverter is oversized - it won't result in a great loss in yield, if any at all, but you have paid extra for it which isn't really fair, is it?

 

[GaryM]

I get a bigger yield with an IG TL 30 on this system. I agree that the inverter is oversized - it won't result in a great loss in yield, if any at all, but you have paid extra for it which isn't really fair, is it?

I get lower. Would location play a big part as I used my location near Manchester.
Both systems wired as a single string of 14 panels.

Eversolar TL4000 - 2841.7kWh
Eversolar TL3200 - 2825.2kWh
Stecagrid 3000 - 2816.6kWh
Secagrid 3600 - 2811.5kWh
Fronius IGTL3.6 - 2797.8kWh
Fronius IGTL3.0 - 2791.9kWh
PowerOne PVI3600 - 2775.4kWh

 

[moggy1968]

yes it would, the further north you go the lower your yield so the more severe the effect of oversizing the inverter becomes.
I don't know what the start up viltage is on this inverter but the other problem that you can get by oversizing is that although the voltage is ok now, in a few years time as the panel voltage drops off, you may fail to achieve start up voltasge some days.

 

[GaryM]

yes it would, the further north you go the lower your yield so the more severe the effect of oversizing the inverter becomes.
I don't know what the start up viltage is on this inverter but the other problem that you can get by oversizing is that although the voltage is ok now, in a few years time as the panel voltage drops off, you may fail to achieve start up voltasge some days.

I was meaning would inverter A yeild more than inverter B in one location yet yeild less in another location?

125-550V for the EverSolar TL4000 so shouldn't be a problem.

 

[SolarCity]

Hmm, I get a slight increase in yield in both my location and Manchester.

 

[stavtoon]

I will add that im in County Durham if that helps.http://pvoutput.org/list.jsp?userid=5754

 

[Grumpy]

Why is 5m of 2.5mm t&e not suitable? At 16A I calculate the voltage drop to be 1.44v or 0.63% well within tolerance I thought.

 

[JulianC]

In this case it is suitable.

 

[moggy1968]

Why is 5m of 2.5mm t&e not suitable? At 16A I calculate the voltage drop to be 1.44v or 0.63% well within tolerance I thought.

yes it is, just that I tend to use 4mm, although you should check the inverter manufacturers instructions as well. I know SMA reccommend minimum 4mm on many of their inverters, dunno why but manufacturers instructions is manufacturers instructions I guess!

 

[powervan]

Manufacturers are like fitters all have there own ways of doing it !! WHO is RIGHT !! thats wot forums for ) now im off for a pint!! if your on here after 7pm tonite take a look in the MIRROR lol