Solar installers in Worcs

am3n3

Hopefully I have just one final question before I accept a quote:
On 3.3-3.6 kWp system the quote included a SolarEdge 3500 HD Wave inverter.

On a new quote for a 3.9 kWp system, this was changed to a SE 3680 version. Is this technically necessary? Alternatively, would buying an inverter with larger DC power capacity be sensible if I wanted to upgrade to higher-capacity panels in the future?

pinnks

It is always better to drive the inverters near the power rating than to future-proof in hope you may extend the system. Apparently they are more efficient but going for a 3680 inverter on a 3.9kWp system would probably be sensible compared to a 3500 subject to price difference as you should get no capping of the output. That said, a 3.9kWp system may not generate much more than 3.5kW one most says unless you are south facing, south east England, perfect roof pitch and so on.

My big inverter is 3600 with 3500Wp of panels; my small inverter is 1500 with 1750W of panels.

Martyn1981

I'm with pinnks, I think both inverters seem appropriate to the kWp sizes. A 3500 might be fine for the bigger system (that's the size I have) but 3680 is also fine, and as you say gives you future proofing.

A friend, who gave me a tour of his PV back when I was green and knew nothing, is now thinking of exactly this, with an upgrade to his 185Wp panels from 2010, assuming the FiT provider has no issues with the change and apportioning generation going forwards.

I'm also pondering the idea when I make some changes in a few years time - adding a small ground mount system and battery - as I have 5 235Wp panels on a low roof, and it might be worth swoping them out for ~330Wp each, assuming all my plans fit within the inverter limitations and FiT rules.

theboylard

For future proofing and a longer warranty, if the 3680 version is a an SE3680H inverter (HD Wave) then yes, grab it.
If its an older model (ie not HD), then the installer has found some old stock - this either helps him offer more for a lower price, or gives him more profit?


They both do the same job, but the HD wave can actually do a bit more than the old one and it's also a lot smaller/lighter. The extended warranty is also cheaper on an HDWave.


Just my thoughts...

am3n3

I'm finally going to accept a quote, coming from Forever Green:
14 x 335W LG Neon 2 panels (total 4.69 kWp)
SolarEdge 3680 HDWave inverter, & optimisers + 20yr extended warranty
iBoost
ModBus (which I'll have for export monitoring to help decide what size for a future battery storage system)
DNO fast-track battery application (offered as a 'freebie')
Total = £7,744

CTS hasn't come back to me after I asked them to spec a larger system than I originally had in mind, which is strange considering they came out to do a survey a couple of weeks ago.

I hummed & hawed about spending extra for LG larger-capacity panels, but I decided it was a slight compromise to spending even more on Sunpower panels. Hopefully the extra I will pay will be reflected in the long-term reliability & efficiency of the panels.

Thanks to everyone for all the advice on this and other related posts and helping me make an informed decision on a big investment.

ASavvyBuyer

am3n3 wrote: »

I'm finally going to accept a quote, coming from Forever Green:

Hope you are happy with Forever Green. They did a good job for us and the system is working well.