Bob's Home

Overview

• Location: Aylesbury

• Date of Installation: January 2025

• Type: Residential

• Roof Layout: South-East & North-East

• Panel Count: 15 Jinko Tiger Neo 440W N-Type All Black Mono Solar Panels

• System Size: 6.6 kW

Hardware Used

• Inverter: Tesla Powerwall 3 + Gateway
  
  

• Battery: Tesla Powerwall 3 with Backup Gateway (13.5 kWh)
  
  The Tesla Powerwall 3 is a 13.5 kWh battery storage system is designed to enhance the efficiency of a solar photovoltaic (PV) system. It allows excess solar energy generated during daylight hours to be stored and used when solar production is low, such as at night or during cloudy periods.

  Without battery storage, a portion of the solar energy generated is typically exported to the grid at circa 15p/kWh instead of displacing energy that would be normally imported to the property at 25p/kWh, making a potential 10p/kWh saving The Powerwall 3 increases self-consumption by an additional 23%, reducing reliance on imported electricity from the grid.

  With the inclusion of battery storage, the household's total grid independence has increased to 55%, meaning more than half of the annual electricity consumption is met by solar energy.

  The Powerwall 3 includes a Backup Gateway, which allows for continued power supply during grid outages. This ensures that essential appliances can continue operating during power failures.
  
  

• Mounting: Fastensol pitched roof mounting system
  
  

• Ancillary Items: Isolators, wiring, meters, and other electrical components

Installation Process

• Timeline: Completed within a short period with minimal disruption to the household

Performance and Financial Projections

• Estimated Annual Energy Generation: 5,115 kWh

• Annual CO₂ Savings: 1,059 kg CO₂

• Estimated First-Year Savings: £1,044

• Payback Period: 15 years

• Total Installation Cost: £15,527 (including VAT)

Financial Breakdown

• Smart Export Guarantee (SEG) Eligible: Yes

• Expected Electricity Usage Contribution:

  • Direct Use from Solar: 2,686 kWh

  • Usage from Battery Storage: 1,974 kWh

  • Exported to Grid: 2,345 kWh

  • Imported from Grid: 3,840 kWh

Environmental Impact

• Reduction in Carbon Footprint:

  • Annual Carbon Offset: 1,059 kg CO₂

  • Equivalent to:

    • Driving 3,782 miles

    • CO₂ absorbed by 49 trees

Live Monitoring and Updates

• Real-time monitoring of system performance available via Tesla Gateway

• Performance tracking with sunpath diagrams and shading calculations

Frequently Asked Questions (FAQs)

How does shading affect the system?

• The shading factor for this installation is estimated at 1.00, ensuring optimal energy generation with minimal losses.

What is the expected performance over time?

• While solar panels experience minor degradation, Jinko Tiger Neo panels offer long-term efficiency and reliability.

Can excess electricity be sold back to the grid?

• Yes. The system qualifies for the Smart Export Guarantee (SEG), enabling surplus energy to be fed back into the national grid for payments.