Battery retrofit to existing solar system
Self-consumption increased from approximately 35% to approximately 70% with a new hybrid inverter and tariff setup.
- Location
- Newton Abbot, Exeter and Devon
- Property
- 3-bed Semi-detached
- Service
- Battery Storage
- Date completed
- 2025
The situation
Existing 3.6 kW solar system installed 3 years ago by another company. Customer exporting most generation. Inverter not battery-compatible. Consumer unit space limited.
What we designed and installed
GivEnergy 5.2 kWh battery with a new hybrid inverter replacing the existing string inverter. Consumer unit upgraded to accommodate battery circuit. Monitoring reconfigured and Octopus Flux tariff set up.
| Component | Specification |
|---|---|
| Solar PV | Existing 3.6 kW |
| Inverter | Hybrid inverter |
| Battery | GivEnergy (5.2 kWh) |
| Monitoring | GivEnergy monitoring |
| Tariff configured | Octopus Flux |
How we set it up
The new inverter and battery dispatch profile were commissioned around evening demand, with import/export behaviour verified against tariff windows.
Results
Self-consumption increased from approximately 35% to approximately 70%. Saving approximately GBP480/year with tariff optimisation. Battery payback projected at approximately 5.5 years.
| Metric | Value | Basis |
|---|---|---|
| Self-consumption | Approximately 70% | Estimated |
| Annual savings | Approximately GBP480/year | Estimated - Octopus Flux |
| Estimated payback | Approximately 5.5 years | Estimated (based on current tariff rates) |
Results labelled estimated are based on system modelling and typical usage patterns. Results labelled observed are based on actual monitoring data collected after installation. Observed results may differ from estimates due to weather, usage changes, and tariff adjustments.
The installation
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