1. PV. PhotoVoltaic panels, ………

Manufacturing costs for these PV panels has drastically reduced over the last 20 years, and therefore making Renewable Energy electricity production at a very good cost effective solution.  All PV production is a DC voltage and this will need to be converted to a AC domestic voltage for a normal house.

On average 15,000 Watts, or 15kW is about for a normal dwelling/house, so 15kW of PV would take  a required space/size in your garden with a PV array of between  20 meters by 5 meters and 25 meters by 3.4 meters

That would be for 60 panels at 250w each and 1.6m x 1m each, 3 rows of 20 would be 20 meters by 5 meters.

For the latest up to date more efficient PV panels at 330w that are 1.8m by 1.1m each, 3 rows of 16 would be a space of 18 meters by 5.4 metres.  

In 2019 15kW of PV Mono Crystalline panels can be from 4.500e to 9,200 Euros. 

In 2020 3.7kW of PV Mono Crystallinepanels, 10off 370w  Longi PV panels with transport fees etc, $1920 or 1600 euros,


For best results your PV should be directly faceing the sun and angled to face the sun at Midday on the days of the Spring or Autumn Equinox.


The different stages of fitting PV rail brackets to a Slate roof.

This building roof, 6 meters by 6 meters, is having a new roof fitted, so an ideal time to prepare for covering the South facing side, (Northern Hemisphere) with 3.3kW of PV.

A 3.7kW Photovoltaic PV, electrics installation.

A 3.7kW Photovoltaic PV, and its electrics installation, that will join my other 14kW of PV that we have here that is also collecting the sun light.

These are UpToDate, Dec 2020, LONGI 370w split monocrystalline PV panels, each panel is 1760mm x 1040mm and 35mm thick. Each has a maximum output of 40.5vdc at 9.1amps.

Firstly, SAFETY, High voltages are dangerous, if you are not sure then please!, please! ask a competent qualified person.


This electrics installation is for France and complies to the French regulations, which after all these years I actually like. The earth system here is a 1.5m rod bashed into the ground and linked to the distribution fuse boxes with a earth 16mm/2 cable.  MCB’s here are 2 pole, so both N & L are protected, in France we do not use a common Neutral bond/bus bar, nor do we bond the Neutral to the Earth.

For this installation on the south side of the new garage slate roof, I have 2off used/second-hand 1700W SMA Grid Tied Inverters, GTI’s.  These will feed into the OzInverter created 240vac Mini Grid.   Therefore, I have split the 10off PV panels into 2 strings of 5 panels each, and those 5 panels will give a maximum of 202.5vdc at 9.1amps into each GTI. 

The 2 GTI inverters will convert the 202.5vdc into 240vac and this will feed back into the OzInverter MINI GRID that is connected to all the 8 buildings here.

If the electricity being created by the PV is not being used around the buildings, then any excess will back feed through the OzInverter and re-charge the batteries.  If the batteries are fully charged then the AC voltage will rise slightly by a few volts and shut the SMA GTI inverters down. 

 Please note, it is very important for the life and longevity of your batteries, that they MUST NOT BE OVERCHARGED.

So setting the GTI shut down voltage is specialised for each GTI, as its location for voltage drop/droop, and its own internal settings do vary.   Dc battery voltage Comparator circuits can also be used to operate a relay at the GTI to shut it down.  Another method is redirection circuit or specialised battery controllers that sends excess power to Dump Loads or other uses like underfloor heating or swimming pool heater etc.

Costs so far, the 10off Longi PV panels with transport fees etc, $1920 or 1600 euros,  2off SMA 1700 used GTI’s, total $204 or 170 euros.

10 Longi PV panels, 1760mm x 1040mm propped up inside awaiting electrical testing.

The Initial stage of installation of the electrical boxes and hardware, wire trunking and the 2 GTI Inverters installed.     

NOTE ..... The white back board is plasterboard over a 18mm plywood backboard, its good as this install is inside a wooden garage, and it also gives the securing screws something to really grip into.   And those GTI inverters are 30kgs each.

Next is installing the PV rails that will take the 10 PV panels.