2 x 355w panels need tie inverter advice please

[mikaj66]

2 x 355w panels need tie inverter advice please
i have a 28 panel array on my main roof 7.8kw with 3 x batteries i have 2 spare 355w panels from another job im planing to put on my garden room roof
i understand it may be possible to hook them up to an inverter/s and put that energy into my home grid.
i assume this would power my residual devices.
i dont plan to add a battery to this 2 panels but i could if necessary.
so looking for a shopping list for my electrician to get the job done.
i have sourced the brackets for flat roof so thats a start and Sonoff Pow R2 Remote Control WiFi Switch Smart Energy Monitoring Consumption UK to monitor and remote switch.
so what inverter would you recommend please and am i right assuming how to go about this additional set up it would be stand alone from my larger roof set up
thanks
mike j

 

[MichaelK]

This sounds like a solution, looking for a problem to solve? You don't seem to have any real plan at all, except to figure out what to do with extra panels.

You do NOT want to connect them in any way to your existing grid-connected home. That is VERY illegal, and potentially dangerous to power company employees working on the power lines. You would need a transfer switch, or a proper either/or switching panel to keep the two sources of power totally separate from each other.

What you can do is create a modest off-grid system to power a few select items that don't consume too much power. It will require batteries, a charge controller, and an inverter, though you might go the batteries + AiO route.

I see you are in the UK, so I'd expect your winter sunhours to be low, maybe 2.0sh? Can you tell me the values for your area? I'd expect you to be able to make about 1.4kWh of power per day in winter on a clear day. I'd say a 24V system with four 6V golf-cart batteries, and something like a MPP AiO. Enough to power your lights, a television, and charge your laptop.