Summary
In 2025, a UK homeowner fully documented the impact of installing solar panels and Tesla Powerwall batteries on their household's energy consumption and costs. The setup included 14 Perlight solar panels and three Tesla Powerwall 2 batteries, configured to maximize cost savings by shifting energy use to off-peak periods. Throughout the year, the homeowner tracked energy import, export, and solar production, revealing significant financial savings and a substantial decrease in grid dependency. This case study provides insights into the effectiveness of solar power in less sunny climates and the financial benefits of smart energy management.
Highlights:
- Annual savings reached £3,857 by using solar power and battery storage.
- Electricity costs significantly reduced from £350-£400 to £50-£100 monthly.
- Solar setup and battery allowed for nearly full off-peak energy usage.
- Exported energy in summer months offset the total electricity costs.
- Long-term savings projected with a ROI of approximately 9% per year.
Throughout 2025, the homeowner utilized a combination of 14 Perlight solar panels and three Tesla Powerwall 2 batteries to optimize household energy use. The solar panels, despite the UK's limited sunshine, managed to produce 3.2 MWh of energy over the year. The Powerwalls were instrumental in shifting consumption to cheaper off-peak hours, resulting in substantial cost reductions. The system's configuration allowed for minimal grid energy use during peak hours, maximizing financial savings.
The homeowner's energy management system displayed a significant reduction in grid dependency. By shifting to off-peak energy consumption facilitated by the battery storage, the household saw a decrease in electricity costs from an average of £350-£400 per month to just £50-£100. During the summer, the solar panels produced excess energy, which was exported back to the grid, earning the household credits that offset their already reduced energy bills, sometimes even earning them money back.
The financial analysis for 2025 showed that the total investment in the solar panels and batteries was £39,360. The savings in electricity costs amounted to £3,857 for the year, projecting a full return on investment in approximately 11 years, with an annual return of about 9%. The system not only reduced costs but also provided energy security during power outages, highlighting both economic and practical benefits of solar and battery integration in residential settings.