7.2KW JA Solar with 10kWh Battery

Full Installation Walkthrough

This project in Darlington is particularly noteworthy because it required a G99 application to Northern Powergrid before the installation could proceed. Many homeowners are unaware that solar installations above 3.68KW per phase require formal permission from the local Distribution Network Operator, and this video provides a detailed explanation of what the G99 process involves, why it exists, and how ALPS Electrical manages the entire process on behalf of our customers.

The G99 application process exists to ensure that the local electricity network can safely accommodate the additional generation capacity being connected. When multiple properties in an area install solar panels, the cumulative effect of all that generation feeding back into the grid can cause voltage rise issues on the local transformer and cables. The DNO needs to assess whether the network infrastructure can handle the proposed new generator without adversely affecting the supply quality for neighbouring properties.

For this project, we submitted the G99 application to Northern Powergrid approximately eight weeks before the planned installation date. The application included the full system specification: the total array capacity of 7.2KW, the inverter type and rating, the connection point details, and the property address. Northern Powergrid then assessed the application against their network models and confirmed that the local infrastructure could accommodate the system without requiring any network reinforcement works.

With the G99 approval secured, we proceeded with the installation. The property is a spacious detached house on the outskirts of Darlington with a large south-facing roof that provided an excellent platform for the solar array. Our site survey had identified the optimal panel layout, and the homeowner had approved the system design including the panel positions, inverter location and battery placement.

The JA Solar panels were installed across the main south-facing roof using our standard mounting system. The array was arranged in a neat rectangular configuration that maximised the use of the available roof space while maintaining appropriate clearance distances from the roof edges and ridge line. Each panel was connected with MC4 connectors and the strings were wired to optimise the voltage and current characteristics for the selected inverter.

Inside the property, we installed the hybrid inverter and a 10kWh battery storage system. The 10kWh capacity provides ample storage for a typical family home, capturing enough surplus solar energy during the day to power the property through the evening and into the night. The system was configured with intelligent charge and discharge scheduling that takes into account the homeowners electricity tariff and typical daily consumption pattern.

The electrical integration required careful planning because the existing consumer unit was an older split-board design that needed upgrading to accommodate the additional circuits for the solar and battery system. We replaced the consumer unit with a modern dual RCD board featuring individual RCBO protection on every circuit, which not only accommodates the new solar and battery connections but also brings the entire electrical installation up to the current eighteenth edition wiring regulations standard.

Full testing and commissioning was carried out in accordance with both MCS requirements and BS 7671, with particular attention to the G99 compliance testing that verifies the inverter protection settings are correctly configured to disconnect from the grid if voltage or frequency deviates outside the permitted limits. These protection settings are critically important for network safety and are verified as part of every G99-connected installation we complete.

The commissioning notification was submitted to Northern Powergrid confirming the installation was complete and the protection settings had been verified. The generation meter was installed and the system was registered with the Smart Export Guarantee scheme for export payments. All MCS documentation was completed and filed, and the homeowner received a comprehensive handover pack including all certificates, warranties and operating instructions.

This project is a good reminder that choosing an experienced, MCS-certified installer like ALPS Electrical matters, particularly for larger systems that require G99 approval. We manage the entire G99 application process as part of our standard service, ensuring that the necessary approvals are in place before our installation team arrives on site. Some less experienced installers are not aware of the G99 requirement or attempt to install systems without the necessary approval, which can result in the DNO requiring the system to be disconnected or de-rated. With ALPS Electrical, you can be confident that every aspect of the installation is handled correctly, from initial design through to final commissioning and DNO notification.