What Happens During a Tesla Powerwall 3 Installation?
If you have ordered a Tesla Powerwall 3 or are considering one, you probably want to know exactly what the installation process involves. As Tesla Certified Installers who have completed numerous Powerwall 3 installations across the North East, we can walk you through every step from initial survey to the moment you first see your system generating on the Tesla app.
Step 1: The Site Survey
Every Powerwall 3 installation starts with a thorough site survey. Our surveyor visits your property to assess the proposed Powerwall mounting location, plan the cable routing between the Powerwall and your consumer unit, check your existing electrical installation for compatibility, survey your roof for the solar panel array (if included), and identify any potential challenges that need to be addressed before installation day.
The survey typically takes 45-60 minutes. We photograph everything, take measurements and discuss your preferences for equipment positioning. The Powerwall 3 can be wall-mounted indoors or outdoors, and the ideal location balances cable run length, accessibility and aesthetics.
Step 2: Design and DNO Application
After the survey, our design team creates a detailed system layout including panel positions, cable routes and equipment locations. For systems over 3.68kW per phase, we submit a G99 application to Northern Powergrid. This process typically takes 4-8 weeks, and we submit it immediately after your order confirmation so the approval is usually received before your installation date.
Step 3: Installation Day — Scaffolding and Preparation
On the first day of a combined solar and Powerwall installation, our scaffolding partners erect the scaffold around the working areas of your roof. We use NAPIT-registered scaffolders who understand the specific access requirements for solar installations. While the scaffold is going up, our electricians begin the internal work: preparing the mounting position for the Powerwall and Backup Gateway, running cables from the loft space down to the equipment location, and installing any new circuits required in the consumer unit.
Step 4: Solar Panel Installation
If your Powerwall 3 is being installed alongside a solar array, the roof work typically takes one full day. Our installers fit the mounting rails to the rafters using waterproof flashings, level the rail system to create a perfectly flat mounting plane, and then secure the panels into position. The Powerwall 3 has a built-in solar inverter, so the DC cables from the panels run directly into the Powerwall unit, eliminating the need for a separate string inverter.
Step 5: Powerwall and Gateway Mounting
The Tesla Powerwall 3 weighs approximately 130kg, so mounting it requires two experienced installers and the correct lifting technique. We secure the mounting bracket to the wall first, ensuring it is perfectly level and fixed into solid masonry or structural timber. The unit is then lifted into position and locked onto the bracket. The Backup Gateway is mounted adjacent to the Powerwall and connected to your consumer unit, enabling the automatic transfer switch that provides seamless backup power during grid outages.
Step 6: Electrical Connections and Testing
With all hardware physically installed, our lead electrician completes the AC and DC wiring connections, installs protection devices in the consumer unit, and carries out comprehensive testing. This includes continuity testing of all circuits, insulation resistance measurements, earth fault loop impedance testing, and RCD trip time verification. Every test result is recorded on the electrical installation certificate.
Step 7: Commissioning
Commissioning is the process of bringing the system online and configuring it through the Tesla Installer Portal. Our Tesla-trained technician connects the Powerwall to your home WiFi network, registers the system with Tesla, configures the backup power settings, sets up your time-of-use tariff schedule if applicable, and verifies that the automatic transfer switch operates correctly by simulating a grid outage. You will see the system appear in your Tesla app within minutes of commissioning.
Step 8: Customer Handover
The final step is a thorough handover where we walk you through the Tesla app, explain how to monitor your system, adjust settings and optimise your energy usage. We provide a complete handover pack including MCS certificates, electrical test certificates, product warranties, and a summary of your system specifications. Most customers are up and running confidently within minutes of the handover.
How Long Does Installation Take?
A Powerwall 3 with solar panels typically takes 2-3 days depending on system size and complexity. A Powerwall 3 added to an existing solar system usually takes 1-1.5 days. Our most complex installation involved a 70-metre cable trench to position the Powerwall in a detached garage, which required additional civil works. Every installation is different, and we provide a clear timeline during the survey stage.
Book Your Installation
Contact ALPS Electrical to book your free Tesla Powerwall 3 survey. As one of the few Tesla Certified Installers in the North East, we offer priority access to Powerwall stock and the expertise to handle even the most challenging installations.