19.1kW Solar with Tesla Powerwall — Part 2

Full Installation Walkthrough

Part two of this landmark installation series picks up where part one left off, with all 44 Jinko Tiger Neo 435W panels now mounted across the three roof faces and the DC wiring ready to be connected to the inverters inside the property. This phase of the project focuses entirely on the electrical infrastructure: the inverter installation, consumer unit modifications, Tesla Powerwall integration and the complex wiring that brings all the components together into a single cohesive energy system.

The internal work began in the utility room, which the homeowner had generously cleared of contents to give our electricians maximum working space. We installed a large dedicated backboard to house both SolarEdge 6KW inverters, the DC isolators, AC isolators and all associated wiring. The backboard was securely fixed to the masonry wall using appropriate fixings rated for the combined weight of the equipment, and we applied a flame-retardant coating as an additional safety measure.

The DC cables from the roof were routed into the utility room through a fire-sealed penetration in the external wall. Each string of panels was terminated at a DC isolator before connecting to the corresponding inverter input. The SolarEdge inverters each handle multiple strings, and we carefully labelled every cable and connection point with permanent markers so that any future maintenance or fault-finding can be carried out quickly and safely without ambiguity about which cable serves which part of the array.

The SolarEdge power optimisers had been installed on each panel during the roof phase, with each optimiser paired to its corresponding panel through the SolarEdge monitoring platform. This means the homeowner can see the individual output of every single panel on their phone, making it immediately obvious if any panel develops a fault or suffers from unexpected shading. This granular monitoring capability is one of the key advantages of the SolarEdge platform over string inverter systems.

The Tesla Powerwall was the centrepiece of the storage solution. We installed the Powerwall unit on the garage wall, which provided the required clearance distances from combustible materials and other equipment. The Tesla Gateway, which manages the switching between grid and battery backup modes, was installed adjacent to the main consumer unit. The Gateway required a complete rewiring of the consumer unit tails to insert itself between the electricity meter and the consumer unit, enabling it to monitor and control the entire electrical supply to the property.

This consumer unit modification is one of the most technically demanding aspects of any Tesla Powerwall installation, and it must be carried out with absolute precision. The Gateway needs to be able to isolate the property from the grid within milliseconds of detecting a power failure, then seamlessly switch to battery backup without any perceptible interruption to the household. Getting the wiring sequence and configuration exactly right is essential for this automatic transfer to work reliably every time.

Our lead electrician carried out the consumer unit modifications, which involved installing a new Henley block at the meter position, running new tails to the Gateway, and then running further tails from the Gateway to the existing consumer unit. All connections were made using appropriately rated terminals and cable, with every joint accessible and clearly labelled for future reference.

The AC output from both SolarEdge inverters was wired to a dedicated solar supply consumer unit, which in turn feeds into the main consumer unit through a correctly rated MCB. This arrangement ensures that the solar generation is properly protected and can be isolated independently from the battery and grid supplies if required for maintenance or fault investigation.

Cable management throughout the installation was given particular attention. On a system of this complexity with multiple inverters, a battery, a Gateway, numerous isolators and extensive cabling, it would be easy for the wiring to become cluttered and difficult to follow. Our electricians used trunking, cable ties and labelling at every junction point to maintain a standard of presentation that matches the quality of the equipment itself.

With all the wiring complete, the team moved on to initial testing. Every circuit was tested for continuity, insulation resistance, polarity and earth fault loop impedance in accordance with BS 7671. The SolarEdge inverters were powered up and configured through the monitoring platform, with each optimiser verified as communicating correctly. The Tesla Powerwall was activated through the Tesla app, and the Gateway was configured for the homeowners preferred backup and self-consumption settings.

The testing phase for a system of this scale is thorough and methodical, and we documented every measurement and configuration setting in the commissioning record that forms part of the MCS certification pack. Part three of this series covers the final commissioning, system testing under load, and the complete walkthrough of the finished installation.