Solar Virgin in need of some advice

[Franksie]

Hi all from the UK. I have just purchased 2 x 405 w solar panels. My idea is to mount them on top of my garage and connect them to a grid tie inverter. I am doing this as a bit of an experiment more than anything kind of dipping my toe into the solar world. I have an EV and am on a very good off peak tariff, this takes care of all the charging. The house is empty most of the day and I can see from my Zappi charger that the house is drawing 0.2KW from the grid. It was just an idea to see if two panels and a grid tie inverter could help reduce this.
My question is which inverter? I appreciate there is a plethora of options, for me it is deciding which one is right for my application. From my basic understanding the inverters need some voltage from the panels in order to boot up. I have looked at the attached and was wondering if anyone with more knowledge could point me in the right direction.
Ebay inverter
Ebay inverter 2
Inverter 3

Am I even looking at the correct ones, all help greatly appreciated.

 

[Rednecktek]

Before you pursue this, have you looked at what kind of hoops you're going to have to jump through to get a grid tie system connected? I think the UK is more lenient on requirements compared to the US but I'm sure there are still hoops.

The simplistic view of how microinverters work (as I understand it) is that the micro sees power from the grid all the time so it can sync up with the grid and all the power is cycling at the same rate and time. The sun comes up and the micro starts drawing power and dumping it into the grid as much as it can get. Without the grid connection the panels don't produce anything, they only provide when ASKED by the system for what it can do.

As opposed to a regular off-grid type system where the charge controller is always trying to charge the system batteries & loads until the batteries and loads are full and ASKS for power from the panels. Panels don't PUSH power, the system ASKS for power and the panels GIVE what they can.

I can see from my Zappi charger that the house is drawing 0.2KW from the grid.

Kw is a measurement of feed rate, not total usage. Kwh is a measurement of volume. 2Kw is only 200w which is about 800w of solar in UK sunlight, but 2Kwh is 200 watts for 10 hours.

Yes, in theory your panels might provide enough power to feed the charger, but it probably won't get sunlight for enough hours to charge the battery much. Going grid-tied is just asking the power company for a discount coupon.

 

[rpdom]

In the UK for a grid tied inverter you will need either a G98 approval - up to 3.68kW - can be applied for after fitting the inverter, or a G99 approval - over 4.68kW output - which must be applied for and granted before connecting the inverter.

To get paid for export you should have an MCS certificate for your installation. However Octopus Energy are considering waiving that requirement in some cases.

There may be other local building regulations to follow too.

 

[mikefitz]

Building regulations, type approval on equipment, approved and tested instalation .

It's virtually impossible without professional involvement