Connecting solar panels to each other

Very straight forward. Each solar panel comes with two MC4 connectors attached to two cables, one positive, one negative. Connect the positive MC4 (Female) to the negative (Male) MC4 of the panel next door.

Keep connecting panels in this way, this is called a 'string'. The maximum number of panels to a string is set by the inverter's maximum voltage. Usually 12 panels.

Inverters typically have two strings (MPPT)/DC inputs - 2 positive, two negative MC4 connectors for solar PV.

You don't have to choose between wiring in parallel or series. Solar panels are wired in series.

Connecting Solar Panels To The Inverter

Once you have all your solar panels, 1 or 2 strings, connected, now you are going to have to connect those MC4s to two lengths of PV cable per string - one for the positive side, one for the negative side and run the cable back to the inverter where they will connect to the inverter's MC4 connections - labelled Solar PV or generation.

To make up your own MC4 connections you may need an MC4 crimping set and wire stripper - available from Amazon for £20-25.

The video below will show you how to make up your own MC4 connectors. The video uses black and red wire - this is purely aesthetic to distinguish between the positive and negative cable - you can do the same with some tape to mark which cable is which.

How to assemble MC4 connectors (Easy DIY).

Source: Youtube

Link to Amazon crimping and wire stripper

Once your solar panels are connected to the inverter

Almost there! Once connected to the inverter, turn the inverter's black DC switch off if it isn't already.

Get a fully qualified electrician to connect the AC side of the inverter to the house. This involves making another circuit on the consumer unit, depending on the cable route to the consumer unit, this could take 1-2 hours, longer if more complex.

Whilst your electrician is doing this, take the time to read the inverters manual or watch the inverters set up video on YouTube!

Once the AC side is connected, turn the AC isolator on and then the black DC isolator on, after 1-2 minutes, the inverter should start generating power.

If no DC is detected - you'll have to go back and check the panel connections. Tip: Ask the electrician to test each DC cable with his/her multimeter.

Make sure the electrician provides the electrical certificate - you will need this to apply to get paid for exporting.

Permission from the grid/DNO (District Network Operator)

Permission from the grid is not required to connect less than 3.68kW per phase. This means 3.68 kW for single phase and 11.04kW for three phase only require a G98 notification - letting the grid know that there is a connection. It is a requirement to tell the DNO so they are aware of a connection.

A G99 application is required for installations installing a larger inverter than 3.68 kW per phase.

This has to be done in advance of your installation so apply as soon as you know what inverter you are planning to use.

We can do either of these for you if you would prefer.

Always use a qualified electrician

You are required to use a fully qualified electrician to work on the electrics of your house.

You will need the Electrical Installation Certificate to apply for exports.

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