Checking proposed installation

[bobsburgers]

Hi,

Complete newbie here, trying to get up to speed so I can check what installers are quoting me! I'm in South-East UK and have a south facing roof. I'm being quoted 20x 380W panels for a 7.6kw system, but only a 3.6kw hybrid inverter. I feel I need a 5kw inverter to handle the load properly. The panels are Q.Cell G9s and the inverters are Givenergy hybrid 3.6kw and 5kw.
Additionally, I'm under the impression that this system is at best going to give me 280W from each panel (based on the data sheet values for a "normal day") for a total of 5.6kw. And after plugging numbers into global solar atlas and other similar tools, I should get around 5kwh per day in winter and 20+ in spring / summer, does this sound about right?

Thanks

 

[MisterSandals]

Additionally, I'm under the impression that this system is at best going to give me 280W from each panel (based on the data sheet values for a "normal day") for a total of 5.6kw.

You seem to me mixing the watts going into the inverter with watts coming out of the inverter. I suspect your "3.6kW" inverter will accept more than 3.6kW.

"normal day"

Its been a long time since i have seen one of these.

Have you looked at a solar irradiance calculator for your location?

Solar Irradiance Calculator

www.solarelectricityhandbook.com

 

[bobsburgers]

Thanks, based on the datasheet the 3.6kw inverter is going to accept at maximum 4.7kw, and the 5kw inverter will accept 6.5kw DC input. I also assume the 3.6kw inverter is only going to output 3.6kw AC power, and will therefore clip quite a bit during the summer for no real gain (the start up voltage etc. is identical for the 2 inverters).

I've checked the solar irradiance calculator which helped produce some of my estimates.

Thanks

Daven

 

[MisterSandals]

I also assume the 3.6kw inverter is only going to output 3.6kw AC power,

Your manual should detail this. I think some hybrid inverters can output more by combining different sources, including passing thru grid current.