Solis 3600 told vs sunnyboy 4000tl

[saggers]

Whats the difference between these 2 units. I've been quoted with the Solis but for 400 more can have the sunny boy. I guess the sunny boy is better built and may last longer? Am I likely to see any extra gains elsewhere. Thanks

 

[whinmoor]

If it's a 4kW system, you should be comparing the Solis 3600 with the SMA SB3600TL-21 SunnyBoy Dual Tracker (not the 4000TL).

SMA is a much better choice if you have any shading whatsoever.

 

[saggers]

Ok I don't seem to suffer from any shading. I will question them why they quoted for that one if the 3600 21 is more suitable, I guess its more money though? I did notice the 4000tl had opti trac shade management any idea what that is?

With no shading is the sunny boy a better investment though? More power or not?

 

[whinmoor]

The SMA 3600-21 is limited to G83 and can therefore be installed without prior permission from the DNO whereas the SMA 4000-21 is not and requires permission. (That's the case in England, anyway - the rules may be different elsewhere).

Opti-trac is a useful feature for shade management but if you don't need that, it's an unnecessary luxury.

I think you'll take a few decades to recover the extra £400 in terms of additional yield. The SMA, however, may be more reliable and the company certainly has a longer history and is more established.

 

[saggers]

Ok I'm rather confused as I've seen a few posts that say a good system is more about the inverter and the design and not the panels used. As for design I am south east facing and no shading so cant see any improvements here. So would I be better off just installing the basic inverter and taking my chances and replace if need be. I'm happy to spend more if it makes sense too.

 

[whinmoor]

The key thing is to choose a good installer. He will select the most suitable components for your circumstances and talk through the pros and cons. Cheapest is rarely best especially when you are making a 20+ year investment which involves major surgery to the fabric of your home.

It's difficult to judge the best solution without a site visit from an experienced technical surveyor. If you had a shiny-suited salesman around, that's probably the company to avoid.